Transcript of методичка гнф
- 1. PART 1 Text 1 Geology (4500) 1. Learn the words and word
combinations before reading: solid matter ['sOlId'mxtq] - encompass
- [in'kAmpqs] - breakdown - ['breikdaun] - constituent -
[kqn'stitjuqnt] - , to be in excess of aqueous - ['eikwiqs] - ,
vapour - ['veipq] - , tripoli ['trIpqlI] suffuse [sq'fjHz] ,
gemstone , nitrogen - ['naitrqdZqn] - exogenous processes - ,
trough - [trOf] - , diverse transformations -[dai'vWs] - 2. Mind
the the prononciation of the following words: Geology -
[dZi'OlqdZi]; Geologist - [dZi'OlqdZist]; Geological
-[dZiq'lOdZikql]; Earth - [WT]; biosphere ['baIq"sfIq] ;
lithosphere ['lITq"sfIq]; hydrosphere ['haIdrq"sfIq]; atmosphere
['xtmqs"fIq]. 3. Read and translate the text: Geology (from Greek:
geo, "earth"; and , logos, "speech" lit. to talk about the earth)
is the science and study of the solid matter that constitutes the
Earth. Encompassing such things as rocks, soil, and gemstones,
geology studies the composition, structure, physical properties,
history, and the processes that shape Earth's components. It is one
of the Earth sciences. The age of the Earth, determined on the
basis of the known rate of breakdown of radioactive elements
entering the crust, is calculated to be in excess of 4,000 Ma* .
Geologists help to locate and manage the Earth's natural resources,
such as petroleum and coal, as well as metals such as iron, copper,
and uranium. Additional economic interests include gemstones
- 2. and many minerals such as asbestos, perlite, mica,
phosphates, zeolites, clay, pumice, quartz, and silica, as well as
elements such as sulfur, chlorine, and helium. The atmosphere (from
the Greek atmo- air and sphaere - sphere) is the layer of the air
which envelops the earth. Essentially it consists of nitrogen and
oxygen with a small quantity of water vapours, carbon dioxide and
certain rare noble gases, notably argon. The hydrosphere (Greek
hydro-water) is the aqueous shell which includes all the natural
waters the waters of oceans, seas, lakes, rivers, which cover more
than 70 of the earths surface, and also the underground waters,
suffusing the rocks of the earth. The lithosphere (Greek lithos-
stone) is the outer solid shell of the earth. Thats the very thing
interesting for geologists. The lithosphere comprises several
shells. The outer cover (shell) of the Earth, known as the Earth's
crust, is the shell on which we live and the one accessible for our
investigation. We obtain most of information concerning the Earth
from our studies of the composition and structure of the Earth's
crust. Throughout this vast span of time the Earth's crust has been
undergoing continual changes. Forces within the Earth, the
so-called endogenous (internal) forces, have caused parts of the
crust to be uplifted or lowered as well as folded and buckled into
high mountains and deep troughs. Always, the exogenous (external)
forces of the Earth such as the wind, water, and extreme variances
of temperature have been at work wearing away all land areas above
the sea. While high mountains in one region were being worn away to
flat plains, the lowlands in other areas were being elevated into
highlands. Thus, portions of the Earth's crust have repeatedly been
raised to great heights and then worn away. The lithosphere is
composed of rocks, such as granite, basalt, sandstone, limestone.
Rocks are complex natural bodies, composed of chemically and
physically simpler bodies called minerals. Examples of minerals are
quartz, feldspar and mica which form granite or calcite which is a
basic constituent of such rocks as limestone and marble. Minerals
in turn are a combination of separate chemical elements. Minerals
are natural bodies, individualized physically or chemically,
arising in the earths crust as a result of physico- chemical
processes, without any particular interference into these processes
by man. The biosphere (Greek bios- life) is the envelope of the
earth which is the site of organic life. This sphere of life as it
were* , the atmosphere, the hydrosphere, and upper part of
lithosphere is a material factor in the diverse transformations and
changes occurring in the parts of the earth near the surface.
Living organisms destroy and alter rocks and minerals that had
formed earlier, which gives rise to* new compounds and new
minerals; furthermore, they themselves furnish* the material for
the accumulation of organic rocks, such as limestones, tripoli,
chalk, coal, etc. Notes: * Ma mega anna (lat.) 106 years, i.e. one
million years 2
- 3. * as it were * to give rise to , * furnish , 4. Revise the
grammatical value of the underlined words. (Clue: they are
participles), name their functions in the sentence. 5. After
reading the text answer the following questions: 1. What is geology
as a science? 2. How many shells does the Earth have? What are
they? 3. What does the atmosphere consist of? 4. What is
hydrosphere? What waters does it include? 5. What is the outer
solid shell of the Earth? What is it composed of? 6. What parts of
the Earth does the biosphere occupy? 6. Shortly describe each shelf
enveloping the Earth. Text 2 The subject matter of geology (2800)
1. Learn the words and word combinations before reading: to be
abundant in - [q'bAndqnt] - to apply - [q'plai] - , , (to) basis
(pl bases) - ['beIsIs] / ['beIsJz] - , , , be concerned with - [
kqn'sWnd] - significance -[sig'nifikqns] - , , foresee - , , hazard
-['hxzqd] - , mudflow margin - ['ma:dZin] - , margins of continents
shallow sea - ['Sxlqu] - subdivision -['sAbdi"viZqn] - epoch -
['i:pOk] - , , fossil ['fOsl] - , ( , ) be very cautious ['kLSqs] -
2. Mind the prononciation of the following geological names:
Palaeozoic ["pxliq' zqVIk] , Archeozoic ["Rki' zqVIk], Proterozoic
["prquterqu' zqVIk], Mesozoic ["mFsqu' zqVIk], Cenozoic
["sJnqu'zqVIk], Cambrian [`kxmbriqn], Ordovician ["LdqV'vISIqn],
Silurian [sai'luqriqn], Devonian [de'vquniqn], Carboniferous
["kRbq'nIfqrqs], 3
- 4. Permian ['pWmiqn], Jurassic [dZu'rxsik], Triassic
[traI'xsIk], Cretaceous [krI'teISqs], Quaternary [kwq'tWnqrI] 3.
Read and translate the text: Geology is the science studying the
history of the earths development. Geology gives the possibility to
establish how the geography of the earths surface changed in
different periods of the earths existence. Studying geology one
comes to know what animals and plants existed in the far off past
and what changes the organic world was subjected to. The subject
matter of geology is to explain the causes and regularities of all
the changes. Geology is concerned with minerals, rocks, organic
remains and with modern geological processes. Geology has an
extremely practical significance, constituting a theoretical basis
of searching and prospecting for different useful materials, all of
which being rocks or minerals. Geologists work to understand the
history of our planet. The better they can understand Earths
history the better they can foresee how events and processes of the
past might influence the future. Here are two examples: 1) The
processes acting upon the Earth cause hazards such as landslides,
earthquakes and volcanic eruptions. Geologists are working to
understand these processes well enough to avoid building important
structures where they will be damaged. If geologists learn a lot
about volcanic mudflows of the past then that information can be
very useful in predicting the dangerous areas where volcanic
mudflows might strike in the future. Intelligent people should be
cautious when considering activities or property development in
these areas. 2) Geologists have worked hard to learn that oil and
natural gas form from organic materials deposited along the margins
of continents and in shallow seas upon the continents. They have
also learned to recognize the types of rock that are deposited in
these near-shore environments. This knowledge enables them to
recognize potential oil and natural gas source rocks. TIME. The
major subdivisions of geologic time are based on organic processes
changes in animal and plant life. The time of earths crust
development is divided into eras; they represent differences of
life forms. Eras are subdivided into periods and this subdivision
is based on the type of life existing at the time and on major
geologic events like mountain building and plate tectonic movement.
Periods are subdivided into epochs based on more specific and
shorter time periods of life and geologic events. Then there are
ages. In the course of formation of the earths crust different
rocks were being developed. The names applied to the divisions of
geologic time and those of the rocks 4
- 5. were not the same, but for reach division of the time scale
there is a corresponding one of the rock scale. Thus we have: TIME
SCALE ROCK SCALE Era Group Period System Epoch Series age stage
There are 5 eras and five corresponding groups of rocks. They are:
Archeozoic era and group Proterozoic era and group Palaeozoic era
and group Mesozoic era and group Cenozoic era and group Archeozoic
and Proterozois eras are not abundant in organic fossils and as a
rule are not subdivided into periods, epochs and ages. The
Palaeozoic era and group are subdivided into Cambrian, Ordovician,
Silurian, Devonian, Carboniferous and Permian periods. The Mesozoic
era has three periods: Jurassic, Triassic and Cretaceous periods.
The Cenozoic era has three periods: Palaeosoic, Neogenic and
Quaternary periods. Each of all these periods is represented by
different forms of organic life. 4. Divide the underlined ingform
words into gerund, participle and verbal noun groups. 5. See to
what passive tense forms are used in the text. 6. Tell your
understanding of: - the subject matter of geology; - the main tasks
of geologists; - the major subdivisions of geologic time and those
of the rocks. Text 3 Rocks (6400) 1. Learn the words and word
combinations before reading: connote - [kO'nqut] - , 5
- 6. specimen - ['spesimin] - , exposure - [iks'pquZq] - , ( )
igneous - ['igniqs] - crystallization - ["kristqlai'zeiSqn] -
abyssal - [q'bisql] - , , adjacent geological stratum -
[q'dZeisqnt] - host - [hqust] - , tungsten - ['tANstqn] - uranium -
[ju'reinjqm] - granite - ['grxnit] - chromium - ['krqumjqm] -
occurrence - [q'kArqns] - , texture - ['tekstSq] - , , , geometry -
[dZi'Omitri] - distortion - [dis'tLSqn] - , facies - , , index
mineral gneiss - [nais] - , , , valuable - ['vxljuqbl] - ,
sillimanite - kyanite ['kiq"nit] -, staurolite ['storq"lit]
olivines - , , pyroxenes - ['pairOksJn] - amphiboles - ['amfq"bol]
( , , , , ) mica - ['maikq] - feldspar - ['feldspa:] - 2. Read and
translate the text: Broadly speaking a rock is an assemblage of one
or (most commonly) two or more minerals (specific chemical
compounds) that form a part of the Earths solid body. A rock
normally connotes an individual specimen one that can be held in
ones hand or is larger but detached from its outcrop (exposure of
the rocks source) so that it has visible boundaries. We know all
rocks to fall into three great divisions termed: 1) sedimentary, 2)
igneous, 3) metamorphic. In this text well read about two of them:
igneous and metamorphic. Igneous rocks (from Latin ignis, fire) are
one of the three main rock types. Igneous rocks are formed by
solidification of cooled magma (molten rock). 6
- 7. Igneous rocks that have solidified without reaching the
surface are termed intrusive or abyssal. Those which have flown out
on the surface as lava before solidifying are termed effusive or
volcanic. Over 700 types of igneous rocks have been described, most
of them formed beneath the surface of the Earths crust. These have
diverse properties, depending on their composition and how they
were formed. Igneous rocks make up approximately ninety-five
percent of the upper part of the Earths crust, but their great
abundance is hidden on the Earths surface by a relatively thin but
widespread layer of sedimentary and metamorphic rocks. Igneous
rocks are geologically important because: their minerals and global
chemistry give information about the composition of the mantle,
from which some igneous rocks are extracted, and the temperature
and pressure conditions that allowed this extraction, and of other
pre-existing rocks that melted; their absolute ages can be obtained
from various forms of radiometric dating and thus can be compared
to adjacent geological strata, allowing a time sequence of events;
their features are usually characteristic of a specific tectonic
environment, allowing tectonic reconstitutions; in some special
circumstances they host important mineral deposits (ores): for
example, tungsten, tin, and uranium are commonly associated with
granites, whereas ores of chromium and platinum are commonly
associated with gabbros. Typical intrusive formations are
batholiths, stocks, laccoliths, sills and dikes. Igneous rocks are
classified according to mode of occurrence, texture, mineralogy,
chemical composition, and the geometry of the igneous body.
Metamorphic rocks are the result of the transformation of an
existing rock type, the protolith, in a process called
metamorphism, which means change in form. The protolith is
subjected to heat and pressure (temperatures greater than 150 to
200 C and pressures of 1500 bars) causing profound physical and
chemical change. Metamorphic rocks make up a large part of the
Earths crust and are classified by texture and by chemical and
mineral assemblage (metamorphic facies). They may be formed simply
by being deep beneath the Earths surface, subjected to high
temperatures and the great pressure of the rock layers above. They
can be formed by tectonic processes such as continental collisions
which cause horizontal pressure, friction and distortion. They are
also formed when rock is heated up by the intrusion of hot molten
rock called magma from the Earths interior. The study of
metamorphic rocks (now exposed at the Earths surface following
erosion and uplift) provides us with very valuable information
about the temperatures and pressures that occur at great depths
within the Earths crust. Some examples of metamorphic rocks are
gneiss, slate, marble, schist, and quartzite. 7
- 8. Metamorphic minerals are those that form only at the high
temperatures and pressures associated with the process of
metamorphism. These minerals include sillimanite, kyanite,
staurolite, andalusite, and some garnet.Other minerals, such as
olivines, pyroxenes, amphiboles, micas, feldspars, and quartz, may
be found in metamorphic rocks, but are not necessarily the result
of the process of metamorphism. These minerals formed during the
crystallization of igneous rocks. They are stable at high
temperatures and pressures and may remain chemically unchanged
during the metamorphic process. However, all minerals are stable
only within certain limits, and the presence of some minerals in
metamorphic rocks indicates the approximate temperatures and
pressures at which they were formed. 3. Determine the form of the
underlined tense structures. 4. Find the gerunds in the text. 5.
After reading the text answer the following questions: 1. What is a
rock? 2. What are the main rock types? 3. What does the word
igneous mean? 4. How many per cent of the upper part of the Earths
crust do the igneous rocks make up? 5. Why are igneous rocks so
geologicaly important? 6. What does the word metamorphism mean? 7.
What does the study of metamorphic rocks provide us with? 8. What
metamorphic minerals can you name? Text 4 Sedimentary rocks (4500)
1. Learn the words and word combinations before reading: common -
['kOmqn] - , , dolomite - ['dOlqmait] - conglomerate -
[kqn'glOmqrqt] - ( ) chemogenic - [kemq'dZenIk] - clastic rock -
['klxstik] - overburden - ["quvq'bWdn] - pressure - ['preSq] -
squeeze - [skwJz] - , , layer - ['leiq] - , , connate fluids -
['kOneit 'flHid] - expel - [iks'pel] - , 8
- 9. diagenesis - ['daIqdZenisis], ( ) chemical - ['kemikql] -
stratum / pl. strata - ['stra:tqm] - , , superposition -
['sju:pqpq'ziSqn] - gradation - [grq'deiSqn] - , , gap - [gxp] - ,
, unconformity - ['Ankqn'fLmiti] - lithification - ['litifi"keiSqn]
- , equal - ['Jkwql] - size - boulder - ['bquldq] - , , cobble -
['kObl] - , ; successive - [sqksesIv] - , 2. Read and translate the
text: Sedimentary rocks formed from sediments cover 75-80% of the
Earths land area, and include common types such as chalk,
limestone, dolomite, sandstone, conglomerate and shale. According
to the agents involved in the deposition of sedimentary rocks we
may have: 1) mechanically formed sediments (clastic rocks), 2)
chemically formed sediments (chemogenic rocks), 3) organically
formed sediments (organic rocks), 4) rocks of mixed origin.
Sedimentary rocks are formed because of the overburden pressure* as
particles of sediment are deposited out of air, ice, wind, gravity,
or water flows carrying the particles in suspension. As sediment
deposition builds up, the overburden (or lithostatic) pressure
squeezes the sediment into layered solids in a process known as
lithification (rock formation) and the original connate fluids are
expelled. The term diagenesis is used to describe all the chemical,
physical, and biological changes, including cementation, undergone
by a sediment after its initial deposition and during and after its
lithification, exclusive of surface weathering. Sedimentary rocks
are laid down in layers called beds or strata. That new rock layers
are above older rock layers is stated in the principle of
superposition.There are usually some gaps in the sequence called
unconformities. These represent periods in which no new sediments
were being laid down, or when earlier sedimentary layers were
raised above sea level and eroded away. The layers may vary as to
kind of material, colour, texture and thickness. 9
- 10. The products of rock decay vary greatly in size, but when
subjected to the action of running water they are sorted and graded
into particles of approximately equal size in accordance with the
strength of current. Grouped then according to the size beginning
with the coarsest, the following names for this material may be
employed: 1) boulders and cobbles (the coarsest), 2) gravel, 3)
sand, 4) clay. Gradation of these into each other is very common.
They are unconsolidated mechanical sediments. Sedimentary rocks
contain important information about the history of Earth. They
contain fossils, the preserved remains of ancient plants and
animals. Coal is considered a type of sedimentary rock. Differences
between successive layers indicate changes to the environment which
have occurred over time. Sedimentary rocks can contain fossils
because, unlike most igneous and metamorphic rocks, they form at
temperatures and pressures that do not destroy fossil remains. The
sedimentary rocks cover only 5% of the total of the Earths crust.
All rocks disintegrate when exposed to mechanical and chemical
weathering at the Earths surface. Mechanical weathering is the
breakdown of rock into particles without producing changes in the
chemical composition of the minerals in the rock. (ice, water,
heating and cooling). Chemical weathering is the breakdown of rock
by chemical reaction. In this process the minerals within the rock
are changed into particles that can be easily carried away.
Sedimentary rocks are economically important in that they can
easily be used as construction material because they are soft and
easy to cut. In addition, sedimentary rocks often form porous and
permeable reservoirs in sedimentary basins in which petroleum and
other hydrocarbons can be found. Notes: * overburden pressure * as
to 3. Find in the text the equivalents: , , , , , , , , , . 4. Make
the resume of the text. 5. Answer the question: why are sedimentary
rocks so important for petroleum geophysicists? 10
- 11. Text 5 Composition of rocks (5400) 1. Learn the words and
word combinations before reading: occur - [q'kW] - , , occurrence -
[q'kArqns] , crystalline structure -['kristqlain] - common -
['kPmqn] halide - [hlad] - , sulfide -['sAlfaId] - , sulfate -
['sAlfeIt] - , luster - ['lAstq] , constituent - [kqn'stItjuqnt] ,
transparent - [trxn'spxrqnt] - brittle - ['brItl] , . effervesce -
["efq'ves] - , substitute for -, 2. Read and translate the text:
Most rocks are composed of minerals. Minerals are defined by
geologists as naturally occurring inorganic solids that have a
crystalline structure and a distinct chemical composition. Of
course, the minerals found in the Earth's rocks are produced by a
variety of different arrangements of chemical elements. A list of
the eight most common elements making up the minerals found in the
Earth's rocks is described in Table 1. Element Chemical Symbol
Percent Weight in Earth's Crust Oxygen O 46.60 Silicon [slkn] Si
27.72 Aluminum [lu:mnm] Al 8.13 Iron [an] Fe 5.00 Calcium Ca 3.63
Sodium Na 2.83 Over 2000 minerals have been identified by earth
scientists. Table 2 describes some of the important minerals, their
chemical composition, and classifies them in one of nine groups.
11
- 12. The Element Group includes over one hundred known minerals.
Many of the minerals in this class are composed of only one
element. Geologists sometimes subdivide this group into metal and
nonmetal categories. Gold, silver, and copper are examples of
metals. The elements sulfur and carbon produce the minerals sulfur,
diamonds, and graphite which are nonmetallic. 12
- 13. Table 2: Classification of some of the important minerals
found in rocks. Group Typical Minerals Chemistry Elements Gold Au
Silver Ag Copper Cu Carbon (Diamond and Graphite) C Sulfur S
Sulfides Cinnabar [snb:] HgS Galena [gli:n] PBS Pyrite [pa()rat]
FeS2 Halides Fluorite [fl()rat] CaF2 Halite [hlat] NaCl Oxides
Corundum [krndm] Al2O3 Cuprite [kju:prat] Cu2O Hematite [hi:mtat]
Fe2O3 Carbonates (Nitrates and Borates) Calcite [klsat] CaCO3
Dolomite [dlmat] CaMg(CO3)2 Malachite [mlkat] Cu2(CO3)(OH)2
Sulfates Anhydrite [nhadrat] CaSO4 Gypsum [dps()m] CaSO4 -2(H2O)
Phosphates (Arsenates, Vanadates, Tungstates, and Molybdates)
Apatite [ptat] Ca5(F,Cl,OH)(PO4) Silicates Albite [lbat] NaAlSi3O8
Augite [:dat] (Ca, Na)(Mg, Fe, Al)(Al, Si)2O6 Beryl [berl]
Be3Al2(SiO3)6 Biotite [batat] K (FE, Mg)3AlSi3O10(F, OH)2
Hornblende [h:nblend] Ca2(Mg, Fe, Al)5(Al, Si)8O22(OH)2 Microcline
KAlSi3O8 Muscovite [mskvat] KAl2(AlSi3O10)(F, OH)2 Olivine [lvi:n]
(Mg, Fe)2SiO4 Orthoclase [:kles] KAlSi3O8 Quartz [kw:ts] SiO2
Organics Amber [mb] C10H16O 13
- 14. The sulfides form an economically important class of
minerals. Many of these minerals consist of metallic elements in
chemical combination with the element sulfur. Most ores of
important metals such as mercury (cinnabar - HgS), iron (pyrite -
FeS2), and lead (galena - PbS) are extracted from sulfides. Many of
the sulfide minerals are recognized by their metallic luster. But
on account of their usual sparing occurrence in rocks only one of
them, pyrite, has a special importance as a rock making mineral.
The halides are a group of minerals whose principle chemical
constituents are fluorine, chlorine, iodine, and bromine. Many of
them are very soluble in water. Halides also tend to have a highly
ordered molecular structure and a high degree of symmetry. The most
well-known mineral of this group is halite (NaCl) or rock salt. The
oxides are a group of minerals that are compounds of one or more
metallic elements combined with oxygen, water, or hydroxyl (OH).
The minerals in this mineral group show the greatest variations of
physical properties. Some are hard, others soft. Some have a
metallic luster, some are clear and transparent. Some
representative oxide minerals include corundum, cuprite, and
hematite. The carbonates consist of minerals which contain one or
more metallic elements chemically associated with the compound CO3.
Most carbonates are lightly colored and transparent when relatively
pure. All carbonates are soft and brittle. Carbonates also
effervesce when exposed to warm hydrochloric acid. Most geologists
considered the Nitrates and Borates being subcategories of the
carbonates. Some common carbonate minerals include calcite,
dolomite, and malachite. The sulfates are a mineral group that
contains one or more metallic element in combination with the
sulfate compound SO4. All sulfates are transparent or translucent
and soft. Most are heavy and some are soluble in water. Rarer
sulfates exist containing substitutes for the sulfate compound. For
example, in the chromates SO4 is replaced by the compound CrO4. Two
common sulfates are anhydrite and gypsum. The phosphates are a
group of minerals of one or more metallic elements chemically
associated with the phosphate compound PO4. The phosphates are
often classified together with the arsenate, vanadate, tungstate,
and molybdate minerals. One common phosphate mineral is apatite.
Most phosphates are heavy but soft. They are usually brittle and
occur in small crystals or compact aggregates. The silicates are by
far the largest group of minerals. Chemically, these minerals
contain varying amounts of silicon and oxygen. It is easy to
distinguish silicate minerals from other groups, but difficult to
identify individual minerals within this group. None are completely
opaque. Most are light in weight. The construction component of all
silicates is the tetrahedron. A tetrahedon is a chemical structure
where a silicon atom is joined by four oxygen atoms (SiO4). Some
representative minerals include albite, augite, beryl, biotite,
hornblende, microcline, muscovite, olivine, othoclase, and quartz.
The organic minerals are a rare group of minerals chemically
containing hydrocarbons. Most geologists do not classify these
substances as true minerals. Note 14
- 15. that our original definition of a mineral excludes organic
substances. However, some organic substances that are found
naturally on the Earth that exist as crystals resemble and act like
true minerals. These substances are called organic minerals. Amber
is a good example of an organic mineral. Notes: * on account of -
-, , 3. Read the following sentences and say if they are taken from
the text or not, if they are not correct, correct them. 1.
According to geologists minerals are naturally occurring organic
solids that have a crystalline structure and a distinct chemical
composition. 2. The Elements Group includes over two hundred known
minerals. 3. Only one of sulfide minerals has a special importance
as a rock-making mineral, its mercury. 4. All carbonates are not
soft and brittle. 5. Phosphates are usually brittle and occur in
small crystals or compact aggregates. 4. Say: - the most common
elements making up the minerals found in the Earth's rocks. - what
organic minerals are. - which group of minerals is the largest one.
PART 2 Text 1 Origin of Oil and Gas (4200) 1. Learn the words and
word combinations before reading: decay - [dI'keI] , trap - [trxp]
n , ( ), ; v , , , , , yield - [jJld] n , , ; ; (); v , , algae
['xldZJ] pl alga - kerogen - bituminous material occurring in shale
and yielding oil when heated to be mature , ( ), protein -
['prqutJn] - , trigger - ['trIgq] - , , squeeze - [skwJz] - , ,
expel - [Ik'spel] , fracture - ['frxktSq] - , , blob - [blPb] - ,
tarry - ['txrI] - , , viscous - ['vIskqs] - , 15
- 16. 2. Read and translate the text: Oil and gas are derived
almost entirely from decayed plants and bacteria. Energy from the
sun, which fuelled the plant growth, has been recycled into useful
energy in the form of hydrocarbon compounds - hydrogen and carbon
atoms linked together. Of all the diverse life* that has ever
existed comparatively little has become, or will become oil and
gas. Plant remains must first be trapped and preserved in sediments
then be buried deeply and slowly 'cooked' to yield oil or gas.
Rocks containing sufficient organic substances to generate oil and
gas in this way are known as source rocks. Whether oil or gas is
formed depends partly on the starting materials. Almost all oil
forms from the buried remains of minute aquatic algae and bacteria,
but gas forms if these remains are deeply buried. The stems and
leaves of buried land plants are altered to coals. Generally these
yield no oil, but again produce gas on deep burial. On burial the
carbohydrates and proteins of the plant remains are soon destroyed.
The remaining organic compounds form a material called kerogen.
Aquatic plants and bacteria form kerogen of different composition
from woody land plants. The processes of oil and gas formation
resemble those of a kitchen where the rocks are slowly cooked.
Temperatures within the Earth's crust increase with depth so that
sediments, and kerogen which they contain, warm up as they become
buried under thick piles of younger sediments. As a source rock,
deposited under the sea or in a lake, becomes hotter (typically
>100o C), long chains of hydrogen and carbon atoms break from
the kerogen, forming waxy and viscous heavy oil. At higher
temperatures, shorter hydrocarbon chains break away to give light
oil and then, above about 160o C, gas. Once a source rock has
started to generate oil or gas it is said to be mature. The most
important products generated are gas, oil, oil containing dissolved
gas, and gas containing dissolved oil which is called gas
condensate. Condensate is the light oil which is derived from gas
condensates to be found at high underground temperatures and
pressures. Migration Much oil and gas moves away or migrates from
the source rock. Migration is triggered both by natural compaction
of the source rock and by the processes of oil and gas formation.
Most sediments accumulate as a mixture of mineral particles and
water. As they become buried, some water is squeezed out and once
oil and gas are formed, these are also expelled. If the water
cannot escape fast enough, as is often the case* from muddy source
rocks, pressure builds up. Also, as the oil and gas separate
16
- 17. from the kerogen during generation, they take up more space
and create higher pressure in the source rock. The oil and gas move
through minute pores and cracks which may have formed in the source
rock towards more permeable rocks above or below in which the
pressure is lower. Oil, gas and water migrate through permeable
rocks in which the cracks and pore spaces between the rock
particles are interconnected and are large enough to permit fluid
movement. Fluids cannot flow through rocks where these spaces are
very small or are blocked by mineral growth; such rocks are
impermeable. Oil and gas also migrate along some large fractures
and faults which may extend for great distances if as a result of
movement, these are permeable. Oil and gas are less dense than the
water which fills the pore spaces in rocks so they tend to migrate
upwards once out of the source rock. Under the high pressures at
depth gas may be dissolved in oil and vice versa so they may
migrate as single fluids. These fluids may become dispersed as
isolated blobs through large volumes of rock, but larger amounts
can become trapped in porous rocks. Having migrated to shallower
depths than the source rocks and so to lesser pressures the single
fluids may separate into oil and gas with the less dense gas rising
above the oil. If this separation does not occur below the surface
it takes place when the fluid is brought to the surface. Water is
always present below and within the oil and gas layers, but has
been omitted from most of the diagrams for clarity. Migration is a
slow process, with oil and gas travelling between a few kilometres
and tens of kilometres over millions of years. But in the course of
many millions of years huge amounts have risen naturally to sea
floors and land surfaces around the world. Visible liquid oil
seepages are comparatively rare, most oil becomes viscous and tarry
near the surface as a result of oxidation and bacterial action, but
traces of natural oil seepage can often be detected if sought.
Notes: * of all the diverse life * as it often the case 3. Say what
verb forms are underlined and name their functions. 4. Answer the
following questions: 1. What is a source rock? 2. Under what
conditions is the gas formed from algae and bacteria? 3. What is
kerogen? 4. When is viscous heavy oil formed? 5. Where do oil and
gas migrate? 6. Is oil less dense than the water which fills the
pore space? Text 2 Trapping Oil and Gas (2750) 17
- 18. 1. Learn the words and word combinations before reading:
spill point fracture -['frxktSq] - , , bubble out ['bAbql 'aut] ,
break , , impervious - [im'pWvjqs] - , , ( . .) reservoir bed -
['rqzqvwa:] - - fault traps - , domed arch - [a:tS] - fold -
[fquld] - , folded petroleum-bearing formation combination trap
truncated - ['trANkeitid] - , , pinch - [pIntS] - . ( ; . ~ out)
piercement dome [piqsi'ment 'dqum]- , spindle top 2. Read and
translate the text: Oilfields and gasfields are areas where
hydrocarbons have become trapped in permeable reservoir rocks, such
as porous sandstone or fractured limestone. Migration towards the
surface is stopped or slowed down by impermeable rocks such as
clays, cemented sandstones or salt which act as seals. Oil and gas
accumulate only where seals occur above and around reservoir rocks
so as to stop the upward migration of oil and gas and form traps,
in which the seal is known as the cap rock. The migrating
hydrocarbons fill the highest part of the reservoir, any excess oil
and gas escaping at the spill point where the seal does not stop
upward migration. Gas may bubble out of the oil and form a gas cap
above it; at greater depths and pressures gas remains dissolved in
the oil. Since few seals are perfect, oil and gas escape slowly
from most traps. A hydrocarbon reservoir has a distinctive shape,
or configuration, that prevents the escape of hydrocarbons that
migrate into it. Geologists classify reservoir shapes, or traps,
into two types: structural traps and stratigraphic traps.
Structural Traps Structural traps form because of a deformation in
the rock layer that contains the hydrocarbons. Two examples of
structural traps are fault traps and anticlinal traps. Fault Traps
The fault is a break in the layers of rock. A fault trap occurs
when the formations on either side of the fault move. The
formations then come to rest* in 18
- 19. such a way that, when petroleum migrates into one of the
formations, it becomes trapped there. Often, an impermeable
formation on one side of the fault moves opposite a porous and
permeable formation on the other side. The petroleum migrates into
the porous and permeable formation. Once there, it cannot get out
because the impervious layer at the fault line traps it. Anticlinal
Traps An anticline is an upward fold in the layers of rock, much
like a domed arch in a building. The oil and gas migrate into the
folded porous and permeable layer and rise to the top. They cannot
escape because of an overlying bed of impermeable rock.
Stratigraphic Traps Stratigraphic traps form when other beds seal a
reservoir bed or when the permeability changes within the reservoir
bed itself. In one stratigraphic trap, a horizontal, impermeable
rock layer cuts off, or truncates, an inclined layer of
petroleum-bearing rock. Sometimes a petroleum-bearing formation
pinches out that is, an impervious layer cuts it off. Other
stratigraphic traps are lens-shaped. Impervious layers surround the
hydrocarbon-bearing rock. Still another occurs when the porosity
and permeability change within the reservoir itself. The upper
reaches of the reservoir are nonporous and impermeable; the lower
part is porous and permeable and contains hydrocarbons. Other Traps
Many other traps occur. In a combination trap, for example, more
than one kind of trap forms a reservoir. A faulted anticline is an
example. Several faults cut across the anticline. In some places,
the faults trap oil and gas. Another trap is a piercement dome. In
this case, a molten substancesalt is a common onepierces
surrounding rock beds. While molten, the moving salt deforms the
horizontal beds. Later, the salt cools and solidifies and some of
the deformed beds trap oil and gas. Spindle top is formed by a
piercement dome. Notes: * come to rest , * seal , , , . 3. Match
the word combinations in the first column with their Russian
equivalents in the second one. Porous sandstone Cap rock Reservoir
shape Layers of rock Fault trap 19
- 20. Faulted anticline Spill point 4. Answer the following
questions: 1. Where do hydrocarbons become trapped? 2. What stops
the upward migration of oil and gas? 3. What are traps? 4. When
does a fault trap occur? 5. What is an anticline trap? 6. When do
stratigraphic traps form? Text 3 How much oil and gas (3650) 1.
Learn the words and word combinations before reading: at a profit
porosity - [pL'rO siti] - , ; permeability - ["pWmjq'biliti] - ,
well log , rock matrix - ['meitriks] - ; core - , fluid saturation
["sxCq'reISqn] - fraction , pressure ['preSq] - ; , drive [draiv]-
; ( , ) , ( ), sealing [sJliN] fault . nonsealing drillsteam test-
drilling rate log = drilling time log ; mud log , tracer 2. Read
and translate the text: 20
- 21. When deciding whether to develop a field, a company must
estimate how much oil and gas will be recovered and how easily they
will be produced. Although the volume of oil and gas in place can
be estimated from the volume of the reservoir, its porosity, and
the amount of oil or gas in the pore spaces, only a proportion of
this amount will be recovered. This proportion is the recovery
factor, and is determined by various factors such as reservoir
dimensions, pressure, the nature of the hydrocarbon, and the
development plan. More specifically, petroleum engineers have to
know: -- the pore spaces of a rock (porosity). Porosity is the
volume fraction of space not occupied by the rock matrix. Not only
average porosity is important but also porosity distribution, both
vertically and horizontally. Reservoir porosity is determined from
measurements on cores and well logs using relationships that are
somewhat empirical. -- how the pore spaces are interconnected
(permeability), if permeability is good and the reservoir fluids
flow easily, oil, gas and water will be driven by natural depletion
into the well and up to the surface. -- the nature of the fluids
filling the pore spaces (fluid saturation). Expansion of the gas
cap and water drives oil towards the well bore. Gas and water
occupy the space vacated by the oil. In reservoirs with
insufficient natural drive energy, water or gas is injected to
maintain the reservoir pressure. -- the energy or pressure that may
cause the fluids to flow (drives). Pressure is the driving force in
oil and gas production. Reservoir drive is powered by the
difference in pressures within the reservoir and the well, which
can be thought of as a column of low surface pressure let into the
highly pressured reservoir. -- the vertical and areal distribution
of reservoirs and pore-connected spaces, and -- barriers to fluid
flow (sealing and nonsealing faults, stratigraphic barriers, etc.).
These facts have to be determined from available information, which
probably consists of: surface seismic, gravity, magnetic, and other
geophysical data, borehole logs of various types, cores taken in
boreholes, analyses of fluids recovered in drillstem tests,
production and pressure data, specialized geophysical measurements,
occasionally tracer data, and drilling rate logs, mud logs, and
other well data. Well logs, geologic background, and well-to-well
log correlations supplemented by seismic character studies (will be
seen further) give an overall picture of the stratigraphy and
stratigraphic changes across the reservoir, and pro- duction and
pressure data (and occasionally tracer data) give information about
the connectivity of reservoir members between wells. Surface
geophysical data, while lacking the vertical resolution of borehole
logs and cores, provides the only data source that gives detailed
information about areal distributions. The proportion of oil that
can be recovered from a reservoir is dependent on the ease with
which oil in the pore spaces can be replaced by other fluids like
water or gas. Tests on reservoir rock in the laboratory indicate
the fraction of the original oil in 21
- 22. place that can be recovered. Viscous oil is difficult to
displace by less viscous fluids such as water or gas as the
displacing fluids tend to channel their way towards the wells,
leaving a lot of oil in the reservoir. Each oil and gas reservoir
is a unique system of rocks and fluids that must be understood
before production is planned. Of course all these facts are to be
determined and calculated by a very synergistically working team of
development geologists, geophysicists and petroleum engineers using
all the available data to develop a mathematical model of the
reservoir. Computer simulations of different production techniques
are tried on this reservoir engineering model to predict reservoir
behaviour during production, and select the most effective method
of recovery. For example, if too few production wells are drilled
water may channel towards the wells, leaving large areas of the
reservoir upswept. Factors, such as construction requirements, cost
inflation and future oil prices must also be considered when
deciding whether to develop an oil or gas field. When a company is
satisfied with the plans for development and production, they must
be approved by the Government, which monitors all aspects of oil
field development. 3. Explain the words: porosity, permeability,
fluid saturation, sealing and nonsealing faults, drillstem tests,
stratigraphic changes across the reservoir, areal distribution. 4.
Answer the questions: 1. How can the volume of oil and gas in place
be estimated? 2. What is the reservoir porosity determined from? 4.
What gives detailed information about areal distributions? 5. What
do a geologist and a geophysicist have to know about oil
reservoirs? Text 4 Discovering the underground structure (6300) 1.
Learn the words and word combinations before reading: pattern -
['pxtn] , , , density -['densiti] - - , , , ..; , altitude -
['xltitHd] - , , subsurface picture delineation wells -
[di"lini'eiSqn] - geometric framework spatial elements - ['speiSql]
- slicing validate - ['vxlideit] - 22
- 23. laterally selected event travel time resolution , strong
acoustic impedance [im'pJdqns] contrast acquisition configuration ,
downhole hardware - 2. Read and translate the text: Large-scale
geological structures that might hold oil or gas reservoirs are
invariably located beneath non-productive rocks, and in addition
this is often below the sea. Geophysical methods can penetrate them
to produce a picture of the pattern of the hidden rocks. Relatively
inexpensive gravity and geomagnetic surveys can identify
potentially oil-bearing sedimentary basins, but costly seismic
surveys are essential to discover oil and gas bearing structures.
Sedimentary rocks are generally of low density and poorly magnetic,
and are often underlain by strongly magnetic, dense basement rocks.
By measuring 'anomalies' or variations from the regional average, a
three-dimensional picture can be calculated. Modern gravity surveys
show a generalised picture of the sedimentary basins. Recently,
high resolution aero-magnetic surveys flown by specially equipped
aircraft at 70 - 100m altitude show fault traces and near surface
volcanic rocks. Initially 3D seismic surveys were used over the
relatively small areas of the oil and gas fields where a more
detailed subsurface picture was needed to help improve the position
of production wells, and so enable the fields to be drained with
maximum efficiency. Nowadays 3 D seismic surveys are used for more
detailed information about the rock layers, to plan and monitor the
development and production of a field. The seismic information is
integrated with well logs, pressure tests, cores, and other
engineering/geoscience data from the discovery and delineation
wells to formulate an initial field development plan. As more wells
are drilled, logged, and tested, and production histories are
recorded, the interpretation of the 3-D data volume is revised and
refined to take advantage of the new information. Aspects of the
interpretation that were initially ambiguous become clear as an
understanding of the field builds, and inferences from the seismic
data become more detailed and reliable. The 3-D data volume evolves
into a continuously utilized and updated management tool that
impacts reservoir planning and evaluation for years after the
seismic survey was originally acquired. Types of 3-D Seismic
Analyses 23
- 24. The interpretations that a geophysicist might perform with
3-D seismic data can be grouped conveniently into those that
examine the geometric framework of the hydrocarbon accumulation,
those that analyze rock properties, and those that try to monitor
fluid flow and pressure in the reservoir. These analyses affect and
significantly improve decisions that must be made about volume of
reserves, well or platform locations, and recovery strategy. The
first general grouping is geometric framework. Its a collective
term for such spatial elements as the attitudes of the beds that
form the trap, the fault and fracture patterns that guide or block
fluid flow, the shapes of the depositional bodies that make up a
field's stratigraphy, and the orientations of any unconformity
surfaces that might cut through the reservoir. By mapping travel
times to selected events, displaying seismic amplitude variations
across selected horizons, isochroning between events, noting event
terminations, slicing through the volume at arbitrary angles,
compositing horizontal and vertical sections, optimizing the use of
color in displays, and using the wide variety of other interpretive
techniques available on a computer workstation, a geophysicist can
synthesize a coherent and quite detailed 3-D picture of a field's
geometry. The second general grouping of 3-D seismic analyses
involves the qualitative and quantitative definition of rock
properties. Amplitudes, phase changes, interval travel times
between events, frequency variations, and other characteristics of
the seismic data are correlated with porosity, fluid type,
lithology, net pay thickness, and other reservoir properties. The
correlations usually require borehole control (well logs, cuttings,
cores, etc.) both to suggest initial hypotheses and to refine,
revise, and test proposed relationships. An interpreter develops a
hypothesis by comparing a seismic parameter in the 3-D volume at
the location of a well to the well's informa- tion, often through
the intermediary of a synthetic seismogram or 2-D or 3-D seismic
model. The hypothesis is then used to predict rock properties
between wells, and subsequent drilling validates (or invalidates)
the concept. Gas saturation in sandstone reservoirs is probably the
rock property that has been most successfully mapped by 3- D
seismic surveys. The presence of free gas typically lowers sharply
the seismic velocity of relatively unconsolidated sandstones and
creates a strong acoustic impedance contrast with surrounding rock.
The contrast produces a seismic amplitude anomaly. Since the early
1970s, this "bright spot" effect has been widely exploited to
detect gas saturation with standard 2-D seismic sections. When the
effect occurs in 3- D volumes, gas-saturated sandstones can be
accurately mapped laterally across fields at multiple producing
horizons. The third general grouping of 3-D seismic analyses
consists of those designed to monitor the actual flow of the fluids
in a reservoir. Such flow surveillance is possible if one (1)
acquires a baseline 3-D data volume at a point in calendar time,
(2) allows fluid flow to occur through production and/or injection
with attendant pressure/temperature changes, (3) acquires a second
3-D data volume a few weeks or months after the baseline, (4)
observes differences between the seismic character of 24
- 25. the two volumes at the reservoir horizon, and (5)
demonstrates that the differences are the result of fluid flow and
pressure/ temperature changes. The standard 3-D seismic data volume
is acquired with source and receivers at the Earths surface. It is
logistically possible to put sources and/or receivers in boreholes
and to record part or all of the 3-D data volume with this downhole
hardware. This approach is an active area of research. Depending on
the acquisition configuration, one records various kinds and
amounts of reflected and transmitted seismic energy, which can then
be sorted to provide information on geometric framework, rock
properties, and flow surveillance, just like surface surveys.
Advantages of downhole placement are that higher seismic
frequencies generally can be recorded, thereby improving
resolution, and that surface-associated seismic noise and statics
problems are lessened or avoided. The main disadvantages are that
source and receiver plants are constrained by the physical
locations of available boreholes; borehole seismology can be
affected by tube waves and the like, so downhole placement is not
noise-free; a borehole source cannot be so strong as to damage the
well; and the logistics and economics of operating in boreholes are
complex, though not necessarily always worse than operating on the
surface. One can imagine a time when borehole seismic sources and
receivers might be standard components of the hardware run into
wells and accepted as routine and valuable devices for reservoir
characterization and flow surveillance. The petroleum industry's
twenty-year experience with 3-D seismic surveying is an example of
a technological and economic success. Today, the investment in a
3-D survey typically results in fewer development dry holes,
improved placement of drilling locations to maximize recovery,
recognition of new drilling opportunities, and more accurate
estimates of hydrocarbon volume and recovery rate. These outcomes
improve the economics of development and production plans and make
the surveys cost effective. Notes: * to take advantage of - *
"bright spot" effect 2. Find the sentences in the text with the
word drilling and determine its grammar form. 3. What are ing forms
in the sentence below: By mapping travel times to selected events,
displaying seismic amplitude variations across selected horizons,
isochroning between events, noting event terminations, slicing
through the volume at arbitrary angles, compositing horizontal and
vertical sections, optimizing the use of color in displays, and
using the wide variety of other interpretive techniques available
on a computer workstation, a geophysicist can synthesize a coherent
and quite detailed 3-D picture of a field's geometry. 25
- 26. 4. Answer the questions: 1. When is 3-D seismic survey
used? 2. What interpretations can the geophysicist get with 3-D
seismic method? 3. What does geometric framework comprise in? 4.
Can you name qualitative and quantitative definitions of the rock
structure? 5. Where are the standard 3-D seismic data receivers
located? 6. Why 3-D surveying method is more appreciated nowadays?
ADDITIONAL READING Tasks of a Professional Geologist (11200)
Statement by the National Association of State Boards of Geology
(ASBOG), a non-profit organization comprised of state boards that
have developed and administer national competency examinations for
the licensure/registration of geologists. (in all the states in the
U.S. and the territory of Puerto Rico) The following areas of
professional practice contain generalized and some specific
activities which may be performed by qualified, professional
geologists. Professional geologists may be uniquely qualified to
perform these activities based on their formal education, training
and experience. Under each major heading is a group of activities
associated with that specific area of geoscience practice. The
major areas of professional, geologic practice include, but are not
limited to: Research; Field Methods and Communications; Mineralogy;
Petrology; Geochemistry; Stratigraphy; Historical, Structural,
Environmental, Engineering, and Economic Geology; Geophysics;
Geomorphology; Paleontology; Hydrogeology; Geochemistry; and Mining
Geology and Energy Resources. These areas are specifically included
in the ASBOG examinations to assure geologic competency. Again,
this list represents only a cross-section of possible activities,
and does not include all potential professional practice
activities. Also included in this publication is a listing of
"Other related activities which may be performed by qualified
Professional Geologists." These activities, although not
specifically geoscience in content, may be performed by a
qualified, professional geologist. Research, Field Methods and
Communications ! Plan and conduct field operations including human
and ecological health, safety, and regulatory considerations !
Evaluate property/mineral rights ! Interpret regulatory constraints
! Select and interpret appropriate base maps for field
investigations ! Determine scales and distances from remote imagery
and/or maps ! Identify, locate and utilize available data sources
26
- 27. ! Plan and conduct field operations and procedures to
ensure public protection ! Construct borehole and trench logs !
Design and conduct laboratory programs and interpret results !
Evaluate historic land use or environmental conditions from remote
imagery ! Develop and utilize Quality Assurance/Quality Control
procedures ! Construct and interpret maps and other graphical
presentations ! Write and edit geologic reports ! Interpret and
analyze aerial photos, satellite and other imagery ! Perform
geological interpretations from aerial photos, satellite and other
imagery ! Design geologic monitoring programs ! Interpret data from
geologic monitoring programs ! Read and interpret topographic and
bathymetric maps ! Perform geologic research in field and
laboratory ! Prepare soil, sediment and geotechnical logs ! Prepare
lithological logs ! Interpret dating, isotopic, and/or tracer
studies ! Plan and evaluate remediation and restoration programs !
Identify geological structures, lineaments, or fracture systems
from surface or remote imagery ! Select, construct, and interpret
maps, cross-sections, and other data for field investigations !
Design, apply, and interpret analytical or numerical models
Mineralogy/Petrology ! Identify minerals and their physiochemical
properties ! Identify mineral assemblages ! Determine probable
genesis and sequence of mineral assemblages ! Predict subsurface
mineral characteristics on the basis of exposures and drill holes !
Identify and classify major rock types ! Determine physical
properties of rocks ! Determine geotechnical properties of rocks !
Determine types, effects, and/or degrees of rock and mineral
alteration ! Determine suites of rock types ! Characterize mineral
assemblages and probable genesis ! Plan and conduct mineralogic or
petrologic investigations ! Identify minerals and rocks and their
characteristics ! Identify and interpret rock and mineral
sequences, associations, and genesis Geochemistry ! Evaluate
geochemical data and/or construct geochemical models related to
rocks and minerals ! Establish analytical objectives and methods !
Make determinations of sorption/desorption reactions based upon
aquifer mineralogy 27
- 28. ! Assess the behavior of dissolved phase and free phase
contaminant flow in groundwater and surface water systems ! Assess
salt water intrusion ! Design, implement and interpret fate and
transport models ! Identify minerals and rocks based on their
chemical properties and constituents Stratigraphy/Historical
Geology ! Plan and conduct sedimentologic, and stratigraphic
investigations ! Identify and interpret sedimentary structures,
depositional environments, and sediment provenance ! Identify and
interpret sediment or rock sequences, positions, and ages !
Establish relative position of rock units ! Determine relative and
absolute ages of rocks ! Interpret depositional environments and
structures and evaluate post-depositional changes ! Perform facies
analyses ! Correlate rock units ! Interpret geologic history !
Determine and establish basis for stratigraphic classification and
nomenclature ! Establish stratigraphic correlations and interpret
rock sequences, positions, and ages ! Establish provenance of
sedimentary deposits Structural Geology ! Plan and conduct
structural and tectonic investigations ! Develop deformational
history through structural analyses ! Identify structural features
and their interrelationships ! Determine orientation of structural
features ! Perform qualitative and quantitative structural analyses
! Map structural features ! Correlate separated structural features
! Develop and interpret tectonic history through structural
analyses ! Map, interpret, and monitor fault movement ! Identify
geological structures, lineaments, fracture systems or other
features from surface or subsurface mapping or remote imagery
Paleontology ! Plan and conduct applicable paleontologic
investigations ! Correlate rocks biostratigraphically ! Identify
fossils and fossil assemblages and make paleontological
interpretations for age and paleoecological interpretations
Geomorphology ! Evaluate geomorphic processes and development of
landforms and soils ! Identify and classify landforms ! Plan and
conduct geomorphic investigations 28
- 29. ! Determine geomorphic processes and development of
landforms and soils ! Determine absolute or relative age
relationships of landforms and soils ! Identify potential hazardous
geomorphologic conditions ! Identify flood plain extent ! Determine
high water (i.e. flood) levels ! Evaluate stream or shoreline
erosion and transport processes ! Evaluate regional geomorphology
Geophysics ! Select methods of geophysical investigations ! Perform
geophysical investigations in the field ! Perform geological
interpretation of geophysical data ! Design, implement, and
interpret data from surface or subsurface geophysical programs
including data from borehole geophysical programs ! Identify
potentially hazardous geological conditions by using geophysical
techniques ! Use wire line geophysical instruments to delineate
stratigraphic/lithologic units ! Conduct geophysical field surveys
and interpretations, e.g. petrophysical wellbore logging devices,
seismic data (reflection and refraction), radiological, radar,
remote sensing, electro-conductive or resistive surveys, etc.
Includes delineation of mineral deposits, interpretation of
depositional environments, formation delineations, faulting, salt
water contaminations-intrusion, contaminate plume delineations and
other ! Identify and delineate earthquake/seismic hazards !
Interpret paleoseismic history Hydrogeology/Environmental
Geochemistry ! Plan and conduct hydrogeological, geochemical, and
environmental investigations ! Design and interpret data from
hydrologic testing programs including monitoring plans ! Utilize
geochemical data to evaluate hydrologic conditions ! Develop and
interpret groundwater models ! Apply geophysical methods to analyze
hydrologic conditions including geophysical logging analysis and
interpretation ! Determine physical and chemical properties of
aquifers and vadose zones ! Define and characterize groundwater
flow systems ! Develop water well abandonment plans including
monitoring and public water supply wells ! Develop/interpret
analytical, particle tracking and mass transport models ! Design
and conduct aquifer performance tests ! Define and characterize
saturated and vadose zone flow and transport ! Evaluate, manage,
and protect groundwater supply resources ! Potentiometric surface
mapping and interpretation 29
- 30. ! Design and install groundwater exploration, development,
monitoring, and pumping/injection wells ! Develop groundwater
resources management programs ! Plan and evaluate
remedial-corrective action programs based on geological factors !
Evaluate, predict, manage, protect, or remediate surface water or
groundwater resources from anthropogenic (man's) environmental
effects ! Characterize or determine hydraulic properties !
Interpret dating, isotopic, and/or tracer surveys ! Determine
chemical fate in surface water and groundwater systems ! Make
determinations of sorption/desorption reacti ons based upon aquifer
mineralogy ! Assess the behavior of dissolved phase and free phase
contaminant flow in groundwater and surface water systems ! Assess
and develop well head protection plans and source water assessment
delineations Engineering Geology ! Provide geological information
and interpretations for engineering design ! Identify, map, and
evaluate potential seismic and othergeologic-geomorphological
conditions and/or hazards ! Provide geological consultation during
and after construction ! Develop and interpret engineering geology
investigations, characterizations, maps, and cross sections !
Evaluate materials resources ! Plan and evaluate remediation and
restoration programs for hazard mitigation and land restoration !
Evaluate geologic conditions for buildings, dams, bridges,
highways, tunnels, excavations, and/or other designed structures !
Define and establish site selection and evaluation criteria !
Design and implement field and laboratory programs ! Describe and
sample soils for geologic analyses ! Describe and sample soils for
material properties/geotechnical testing ! Interpret historical
land use, landforms, or environmental conditions from imagery,
maps, or other records ! Conduct geological evaluations for surface
and underground mine closure and land reclamation ! Laboratory
permeability testing of earth and earth materials Economic Geology,
Mining Geology, and Energy Resources (including metallic and
non-metallic ores/minerals, petroleum and energy resources,
building stones/materials, sand, gravel, clay, etc.) 30
- 31. ! Plan and conduct mineral, rock, hydrocarbon, or energy
resource exploration and evaluation programs ! Implement geologic
field investigations on prospects ! Perform geologic
interpretations for rock, mineral, and petroleum deposit
evaluations, resource assessments, and probability of success !
Perform economic analyses/appraisals ! Provide geologic
interpretations for mine development and production activities !
Provide geologic interpretations and plans for abandonment,
closure, and restoration of mineral and energy development or
extraction operations ! Identify mineral deposits from surface
and/or subsurface mapping or remote imagery ! Predict subsurface
mineral or rock distribution on basis of exposures, drill hole, or
other subsurface data ! Evaluate safety hazards associated with
mineral, petroleum, and/or energy exploration and development !
Determine potential uses and economic value of minerals, rocks, or
other natural resources Other related activities which may be
performed by qualified Professional Geologists ! Implement siting
plans for the location of lagoons and landfills ! Environmental
contaminant isocontour mapping ! Conduct water well inventories !
Determine geotechnical aquifer parameters ! Land and water (surface
and ground water) use utilized in planning, land usage, and other
determinations ! Determine sampling parameters and provide field
oversight. Emergency response activities and spill response
planning including implementation and coordination with local,
state, and federal agencies ! Develop plans and methods with law
enforcement, fire, emergency management agencies, toxicologists and
industrial hygienists to determine methods of protection for public
health and safety ! Provide training related to hazardous materials
and environmental issues related to hazardous materials ! Develop
plans and methods with biologists for protection of wildlife during
spill events ! Prepare post spill assessments and remediation plans
! Develop and implement site safety plans and environmental
sampling plans ! Provide educational outreach related to
geological, geotechnical, hydrologic, emergency response and other
activities ! Respond to natural disaster events (i.e. floods,
earthquakes, etc.) for protection of human health and the
environment ! Participate in pre-planning for spill events in
coastal or other environmentally sensitive environments 31
- 32. ! Develop resource(s) and infrastructure vulnerability
assessment plans and reports related to potable and non-potable
water supplies, waste water treatment facilities, etc. Some more
information about rocks (3800) Dykes are intersecting veins. In
inclination dykes may vary from vertical to horizontal. Sometimes
we may observe them extend, outward from larger masses of intruded
rocks. Effusive or volcanic rocks occur in the forms of domes,
sheets and flows. Domes are the names of arched accumulations of
lava solidified in the form of beds similar to those of sedimentary
rocks. Sheets are formed on the surface from quiet outwelling of
highly molten materials through a) localized opening or volcanic
vents and hence connected with volcanic eruptions or b) from
fissures not connected with volcanic eruptions. Sheets are similar
in form to sedimentary strata and extend to large areas. Flows are
formed in the same manner as sheets but they fill negative reliefs
such as valleys and flumes. Flows are much smaller in size than
sheets. Igneous rocks are characterized by a holocrystal line (or
granular-crystalline), glassy and porphyritic structure. Igneous
rocks are subdivided according to their chemical composition. Based
upon the silicon oxide content the rocks are divided into ultra
acid, acid average, basic and ultra basic. The amount of silica
present exercises an important influence on the crystallization of
the magma. The many hundreds of analyses that have been made of
igneous rocks show them to contain the following principal oxides,
silica, alumina, iron oxides, ferric, ferrous, magnesia, lime,
soda, and potash. These principal oxides as composing igneous rocks
do not exist as free oxides, excepting a few cases with but a few
exceptions only in small amounts. TEXTURE OF IGNEOUS ROOKS. By
texture of an igneous rock is meant size, shape and manner of
aggregation of its component minerals. It is considered to be an
important means of determining the physical conditions under which
the rock was formed at or near the surface or at some depth below
and hence is recognized to be one of the important factors in the
classification of igneous rocks. Some rocks are sufficiently
coarse-grained in texture for the principal mineral to be readily
distinguished by unaided eye. In others their minerals are too
small to be seen even with the aided eye. There are also those in
which no minerals appeared to have crystallized. Instead the magma
has solidified as a glass. KINDS OF TEXTURE. Expressing so closely
the conditions under which rock magmas solidify the texture is
recognized to be an important property of rocks and one of the
principal factors in their classifications. 32
- 33. In megascopic description of igneous rocks five principal
textures were reported to exist. They are glassy, dense or
felsitic, porphyritic, granitoid and fragmental. According to the
size of mineral grains we may recognize: 1) fine-grained ; 2)
medium-grained; 3) coarse-grained rocks. DESCRIPTION OF SOME
IGNEOUS ROOKS. Granites are known to be composed of feldspar and
quartz usually with mica or hornblende, rarely pyroxene. The
chemical composition of granite is now regarded to be of less
economic importance than the mineral composition. PHYSICAL
PROPERTIES. The usual colour of granite is reported to be some
shade of grey though pink or red varieties are likely to occur
depending chiefly upon that of the feldspar and the proportion of
the feldspar to the dark minerals. Specific gravity ranges from
2.65 to 2.75. The percentage of absorption is very small. Crushing
strength is very high ranging from 15.000 to 20.000 pounds per
square inch (psi). These properties render the rock especially
desirable for building purposes. DIORITE. MINERAL COMPOSITION. The
diorites are granular rocks which are known to be composed of
plagioclass as the chief feldspar and hornblende or biotite or
both. Augite is likely to be present in some amount and some ortho
- class occurs in all diorites. The name diorite is applied to
those granular rocks in which hornblende is found to equal or
exceed feldspar in amount. Because of the fine-grained texture it
is not possible in many cases to determine by megascopic
examination the dominant feldspar. CHEMICAL COMPOSITION. The most
important points to be observed in the chemical composition of
normal diorites are lower silica content but notably increased
percentages of the bases, iron, lime and magnesia over the
granites. PHYSICAL PROPERTIES. Diorites are usually of a dark or
greenish colour, sometimes almost black depending upon the colour
of hornblende and its proportion to feldspar. They have a higher
specific gravity than granites, ranging from 2.82 to 5.0. They show
a high compressive strength and a low percentage of absorption.
More information about sedimentary rocks (4500) Organic sedimentary
rocks are given this name because of their having been formed
partly or wholly from organic material. The most widely spread are:
limestones, chalk, dolomites, radio-larites, spongiolites, tripoli,
caustobioliths. Sedimentary rocks of chemical origin include a
series of deposits owing to their origin processes that are
chemical in character and formed chiefly by concentration through
evaporating aqueous solutions, changes of temperature, loss of
carbon 33
- 34. dioxide, etc., aided more or less in some cases by the
action of organic life (plants and animals) and resulting in
precipitating insoluble salts. These may be subdivided into
carbonates, siliceous rocks, ferrugineous rocks (iron ores),
sulphates and haloids. Sedimentary rocks of mixed origin include
the rocks which may be formed: 1) partly from clastic and partly
from organic material; 2) from clastic material and that of
chemical origin; 3) from the material of chemical or of organic
origin; 4) from materials of clastic, organic and chemical origin.
Their being of mixed origin results in some properties similar to
those of rocks of organic, chemical and clastic origin. The term
"metamorphic", when broadly applied, includes any change or
alteration that any rock has undergone. It involves changes that
are both physical and chemical, and the rock so altered may have
been originally of sedimentary or igneous origin. The alteration
includes changing in mineral composition or texture or both. This
change being sometimes very great obscures the primary characters
of the original rock, rendering the possibility of defining the
source rock almost impossible. Chemical composition of metamorphic
rocks varies greatly because of the source material having been of
widely different composition. The chemical composition of many
rocks is not greatly changed during the process of metamorphism;
hence, metamorphosed igneous and sedimentary rocks frequently show
the composition characteristic of their class. Chemical analysis
therefore frequently forms an important criterion for
discriminating between metamorphose sedimentary and igneous rocks.
Mineral composition of metamorphic rocks being dependent on
chemical composition leads to wide variations in mineral content of
metemorphic rocks. It has been shown that certain, minerals such as
the feldspathoids (nepheline and sodalite) are characteristic of
igneous rocks. Likewise there are certain minerals which are
considered to be characteristic of metamorphic rocks. Mineral
composition often becomes at important criterion in distinguishing
metamorphosed sedimentary from metamorphosed igneous rocks.
Metamorphic rocks include: marls, clayey limestones, arenaceous
limestones, and others. As has been stated before, igneous rocks
occur in the form of batholiths, laccoliths, stocks, dykes; etc.
The mode of occurrence of metamorphic rocks depends on the kind of
rocks they have been formed from. We shall speak mostly about
sedimentary rocks because of their being of more practical
importance. The principal morphological units of sedimentary rocks
are beds (layers). The layers may vary as to kind of material,
colour, texture and thickness. Variations in thickness of
individual layers may range from a very smell fraction of an inch
up to one hundred feet and more. If we use the terms "layer" or
"bed" which are synonym, we refer to thicker divisions. If the
divisions were thinner we should use the term "lamina". "Stratum"
is generally applied to a single bed or layer of rock while a group
of beds deposited in sequence one above another and during the same
period of 34
- 35. geologic time is known as a formation or suite. The
formation may include beds of both homogeneous and heterogeneous
rocks. Every bed or suite of beds has thickness. We distinguish a
true thickness true thickness, a horizontal thickness and vertical
thickness. The true thickness is the length of the perpendicular
line from any point on the top of the bed to the bottom of this
bed. The horizontal thickness is the length of the horizontal line
from any point on the top to the bottom drawn across. The vertical
thickness is the length of the vertical line drawn from any point
on the top to the bottom. Beds of rocks may be observed in
outcrops. The outcrops occur as artificial or natural ones. As a
rule the primary occurrence of sediments is almost horizontal. If
there is any displacement as to primary position of beds, we call
this displacement a dislocation or faulting. If the dislocation is
not accompanied by discontinuity, it is called a plicative
dislocation should there-be any discontinuity, a disjunctive
dislocation" would result. Both plicative and disjunctive
dislocations are the result of movements of the earth's crust. Had
there been no crustal movements, no dislocations would have
occurred. If the crustal movements are horizontal or nearly so,
plicative dislocations result; if they are vertical or
approximately vertical, the dislocations will be disjunctive.
Plicative dislocations are often accompanied by disjunctive ones,
or vice versa. The occurrence of beds may be conformable and
unconformable, of gentle dip and folded, transgressive etc. The
position of the bed in space is defined by the elements of its
occurrence, that is, by strike and dip. A strike of a bed is the
direction of the line of its intersection with a horizontal plane.
A dip of the bed is its inclination as to the horizontal plane.
Geophysical survey methods (after G. Pratt) (2000) Survey method
Measured parameter Physical Property Major Applications Potentials
Gravity Spatial variations in the local strength of the
gravitational field of the Earth Local variations in density
Mapping of regional structures, sedimentary basins, salt diapers,
plutonic intrusions delineation, sand and gravel deposits, depth to
bedrock Magnetics Spatial variations in Local variations in Mapping
of regional 35
- 36. the local strength of the geomagnetic field susceptibility
and remanence structures, airborne surveys, igneous intrusions, sea
floor spreading, salt structures, mineral deposits, buried
environmental hazards, archeology Electrical Resistivity Earth
resistance (applied voltage / measured current) Electrical
resistivity (conductivity) Mineral prospecting, engineering and
hydrogeology, contaminant mapping, construction site investigation,
groundwater Induced polarization (IP) Voltage decay, or frequency
dependent resistance Electrical capacitance Detection of
disseminated mineral deposits, aquifer mapping, contaminant mapping
Self-potential (SP) Natural electric potential Electro-chemical
activity Mineral prospecting, graphite detection, hydrogeology,
geothermal studies Electromagnetic (EM) Secondary (induced)
electromagnetic fields Electrical conductivity and inductance Deep
mineral prospecting, airborne surveys, conducting faults,
groundwater studies, detection of underground pipes and cables,
agricultural studies Ground Penetrating Radar Traveltimes,
amplitudes, waveforms of reflected electromagnetic pulse Electrical
conductivity, radar image Shallow sedimentary structures, water
table detection, bedrock mapping, mapping of hydrocarbon
contaminants Seismic Earthquake, Microseismic Location of
earthquake, traveltime of elastic waves Compressional, shear
velocity, fracture location Earth mapping at all scales from global
to mine excavation Refraction Traveltimes, amplitudes, waveforms of
refracted elastic waves Compressional, shear wave velocities
Crustal scale to engineering scale mapping of rock types,
structural boundaries, foundations, hydrogeology Reflection
Traveltimes, Compressional, Oil and gas exploration, site 36
- 37. amplitudes, waveforms of reflected elastic waves shear wave
contrasts, density contrasts, seismic image surveying, bedrock
mapping, detection of shallow faults and cavities. Preparing to
Drill (4100) Once the site has been selected, it must be surveyed
to determine its boundaries, and environmental impact studies may
be done. Lease agreements, titles and right-of way accesses for the
land must be obtained and evaluated legally. For off-shore sites,
legal jurisdiction must be determined. Once the legal issues have
been settled, the crew goes about preparing the land: 1. The land
is cleared and leveled, and access roads may be built. 2. Because
water is used in drilling, there must be a source of water nearby.
If there is no natural source, they drill a water well. 3. They dig
a reserve pit, which is used to dispose of rock cuttings and
drilling mud during the drilling process, and line it with plastic
to protect the environment. If the site is an ecologically
sensitive area, such as a marsh or wilderness, then the cuttings
and mud must be disposed offsite -- trucked away instead of placed
in a pit. Once the land has been prepared, several holes must be
dug to make way for the rig and the main hole. A rectangular pit,
called a cellar, is dug around the location of the actual drilling
hole. The cellar provides a work space around the hole, for the
workers and drilling accessories. The crew then begins drilling the
main hole, often with a small drill truck rather than the main rig.
The first part of the hole is larger and shallower than the main
portion, and is lined with a large-diameter conductor pipe.
Additional holes are dug off to the side to temporarily store
equipment -- when these holes are finished, the rig equipment can
be brought in and set up. Setting Up the Rig Depending upon the
remoteness of the drill site and its access, equipment may be
transported to the site by truck, helicopter or barge. Some rigs
are built on ships or barges for work on inland water where there
is no foundation to support a rig (as in marshes or lakes). Once
the equipment is at the site, the rig is set up. Here are the major
systems of a land oil rig: Power system large diesel engines - burn
diesel-fuel oil to provide the main source of power electrical
generators - powered by the diesel engines to provide electrical
power Mechanical system - driven by electric motors 37
- 38. hoisting system - used for lifting heavy loads; consists of
a mechanical winch (drawworks) with a large steel cable spool, a
block-and-tackle pulley and a receiving storage reel for the cable
turntable - part of the drilling apparatus Rotating equipment -
used for rotary drilling swivel - large handle that holds the
weight of the drill string; allows the string to rotate and makes a
pressure-tight seal on the hole kelly - four- or six-sided pipe
that transfers rotary motion to the turntable and drill string
turntable or rotary table - drives the rotating motion using power
from electric motors drill string - consists of drill pipe
(connected sections of about 30 ft / 10 m) and drill collars
(larger diameter, heavier pipe that fits around the drill pipe and
places weight on the drill bit) drill bit(s) - end of the drill
that actually cuts up the rock; comes in many shapes and materials
(tungsten carbide steel, diamond) that are specialized for various
drilling tasks and rock formations Casing - large-diameter concrete
pipe that lines the drill hole, prevents the hole from collapsing,
and allows drilling mud to circulate Circulation system - pumps
drilling mud (mixture of water, clay, weighting material and
chemicals, used to lift rock cuttings from the drill bit to the
surface) under pressure through the kelly, rotary table, drill
pipes and drill collars pump - sucks mud from the mud pits and
pumps it to the drilling apparatus pipes and hoses - connects pump
to drilling apparatus mud-return line - returns mud from hole shale
shaker - shaker/sieve that separates rock cuttings from the mud
shale slide - conveys cuttings to the reserve pit reserve pit -
collects rock cuttings separated from the mud mud pits - where
drilling mud is mixed and recycled mud-mixing hopper - where new
mud is mixed and then sent to the mud pits Derrick - support
structure that holds the drilling apparatus; tall enough to allow
new sections of drill pipe to be added to the drilling apparatus as
drilling progresses Blowout preventer - high-pressure valves
(located under the land rig or on the sea floor) that seal the
high-pressure drill lines and relieve pressure when necessary to
prevent a blowout (uncontrolled gush of gas or oil to the surface,
often associated with fire) 38
- 39. Anatomy of an oil rig Drill-mud circulation system 39
- 40. , , . : 2MnO2 [tu:molikju:lz v em en ou tu:] + , , : +
hydrogen ion [haidridZn ain] univalent positive hydrogen ion
[ju:niveilnt pozitiv hai- dridZn ain] Cu++ divalent positive cuprum
ion [daiveilnt poztiv kju:prm ain] Al +++ trivalent positive
aluminium ion [tri: veilnt poztiv ,ljuminijm ain] Cl negative
chlorine ion [negtiv klo:ri:n ain] negative univalent chlorine ion
[negtiv ju:niveilnt klo:ri:n ain] : : .. Cl :Cl : :Cl:C:Cl Cl C Cl
[si: si: el fo:] :Cl: Cl = :: : .. :::::: == [si: ou tu:] + : plus,
and together with = : give form : give, pass over to lead to ( 3) :
forms is formed from ( 8) form are formed ( 7: . .) ( ) round
brackets [raund brkits] [ ] square brackets [skw brkits] (x)
multiplication sign ( ) ( 10) 40
- 41. 1. 4KCl [fo:molikju:lz v ke si: el] 2. 4HCl + O2 = 2Cl2 +
2H2O [fo:molikju:lz v eit si: el plAs ou tu: giv tu: molikju:lz v
si: el tu: nd tu: molikju:lz v eit tu: ou] 3. Zn + CuSO4 = Cu +
ZnSO4 [zed en plAs si: ju: es ou fo: giv si: ju: plAs zed en es ou
fo:] 4. PCl3 + 2Cl PCl5 [pi: si: el ri: plAs tu: molikju:lz v si:
el giv pi: si: el faiv] 5. H2 + J2 2HJ [eit tu: plAs dZei tu: fo:m
nd a: fo:md frm tu: molikju:lz v eit dZi] 6. C2H2 + H2O CH3CHO [si:
tu: eit tu: plAs eit tu: ou giv si: eit ri: si: eit ou] 7. N2 + 3H2
2NH3 [en tu: plAs ri: molikju:lz v eit tu: fo:m nd a: fo:md frm tu:
molikju:lz v en eit ri: ] 8. AcOH AcO- + H+ [ei si: ou eit fo:mz nd
iz fo:md frm ei si: negtiv oksidZn ain plAs haidrodZn ain ] H | H H
C H [si: eit fo:] | H 9. Al2 (SO4)3 [ei el tu: raund brkits oupnd
es ou fo raund brkits klousd ri: ] 10. ab=c a multiplied by b
equals c Contents: 41
- 42. Part 1 Text 1 Geology (4500) Text 2 The subject matter of
geology (2800) Text 3 Rocks (6400) Text 4 Sedimentary rocks (4500)
Text 5 Composition of rocks (5400) Part 2 Text 1 Origins of Oil and
Gas (4200) Text 2 Trapping Oil and Gas (2750) Text 3 How much oil
and gas (3650) Text 4 Discovering the underground structure (6300)
Texts for additional reading 42