GEO4270 _ RESEVAL
-
Upload
ariefkusman -
Category
Documents
-
view
215 -
download
0
Transcript of GEO4270 _ RESEVAL
-
8/11/2019 GEO4270 _ RESEVAL
1/51
GEO4270 EXERCISE 2
PROSPECT EVALUATION
-
8/11/2019 GEO4270 _ RESEVAL
2/51
Integrated Basin Analysis and Prospect Evaluation
1. Integrated Seismic (reflection/refraction), Gravity and Magneticsand Basin Modelling
Large Scale Structures of the Basin
Tectonic Development of the Basin
Maturation of Hydrocarbons
2. Prospect Evaluation
10/14/2008 GEO4270 - Michel Heeremans2
-
8/11/2019 GEO4270 _ RESEVAL
3/51
Prospect Evaluation
Tampen Spur:
Migration
Troll, Oseberg
,Visund, Tordis
Mature HC
10/14/2008 GEO4270 - Michel Heeremans3
-
8/11/2019 GEO4270 _ RESEVAL
4/51
Prospect Evaluation
Prospect, n.An examination or test of the mineral
the ore, etc. is extracted
, . . .
Evaluation, The action of evaluating ordetermining the value of (a mathematical expression,
a physical quantity, etc.), or of estimating the force of(e.g. probabilities, evidence)
OED, 2.
10/14/2008 GEO4270 - Michel Heeremans4
-
8/11/2019 GEO4270 _ RESEVAL
5/51
Course Contents
Introduction PETREL Introduction Course
Exercise: Statfjord Field a a oa ng
Interpretation
Reservoir Modelling and Prospect Evaluation
Report
Follow up meetings
10/14/2008 GEO4270 - Michel Heeremans5
-
8/11/2019 GEO4270 _ RESEVAL
6/51
Prospect Evaluation Exercise Data
Offshore Norway Northern North Sea
What will we be using during the project: Seismic data
2D
Well data
Formation Tops
eop ys ca we ogs
10/14/2008 GEO4270 - Michel Heeremans6
-
8/11/2019 GEO4270 _ RESEVAL
7/51
WELL LOGGING / CORRELATION
Porosity
SP
GEO4250
Short summary
-
8/11/2019 GEO4270 _ RESEVAL
8/51
Formation Evaluation
Formation evaluation, the process of using borehole
measurements to evaluate the characteristics of subsurface
formations.
e an er, . ., . un amen a s o orma on va ua on
10/14/2008 GEO4270 - Michel Heeremans8
-
8/11/2019 GEO4270 _ RESEVAL
9/51
Formation Evaluation Objectives
Identification of the reservoir (primary)
Reservoir properties Shape
Porosity and permeability Lithology
Well-to-well correlation
Formation dip
Surface seismic well tie
10/14/2008 GEO4270 - Michel Heeremans9
-
8/11/2019 GEO4270 _ RESEVAL
10/51
Hydrocarbons in Place
oiSAh7758 N = initial oil in place (stb)
A = drainage area (acres)
oiB= h = productive interval thickness (ft)
= effective porosity (fraction)
Soi = initial oil saturation (fraction)
oiSAhG 560,43= B
oi= initial oil formation volume factor (reservoir
bbl/stb)
G = initial gas in place (scf)
gi Sgi = initial gas saturation (fraction)
Bgi = initial gas formation volume factor (ft3/scf)
Oil formation volume factor: Oil and dissolved gas volume at reservoir conditions divided by oil volume at
standard conditions.
10/14/2008 GEO4270 - Michel Heeremans10
Gas formation volume factor: Gas volume at reservoir conditions divided by gas volume at standard
conditions.
-
8/11/2019 GEO4270 _ RESEVAL
11/51
Hydrocarbon Reserves
=p
e = effective porosity (fraction) So = Oil saturation (fraction)
oep
h = productive interval thickness (ft) A = drainage area (acres)
=
10/14/2008 GEO4270 - Michel Heeremans11
-
8/11/2019 GEO4270 _ RESEVAL
12/51
Important Parameters
Saturation (S), n. [Formation Evaluation]
The relative amount of water, oil and gas in the pores of a rock, usually.formation water is assumed to contain hydrocarbons. Mathematically thiscan be expressed as:
Shc = 1 Sw
Where Shc = hydrocarbon saturation
Sw = water saturation
If Sw is low, the formation is potentially productive
10/14/2008 GEO4270 - Michel Heeremans12
-
8/11/2019 GEO4270 _ RESEVAL
13/51
Important Parameters
Porosity (), n. [Geology]The percentage of pore volume or void space, or that volume
within rock that can contain fluids.
Total Porosity (t): The total pore volume per unitvolume of rock
Effective Porosity (e): The interconnected pore volumeor void space in a rock that contributes to fluid flow or
10/14/2008 GEO4270 - Michel Heeremans13
-
8/11/2019 GEO4270 _ RESEVAL
14/51
Important Parameters
Permeability (k), n. [Geology]The ability, or measurement of a rock's ability, to transmit
fluids.
Permeability is required to calculate the flow rate at which
hydrocarbons can be produced, following Darcy law:
dkdx
u
10/14/2008 GEO4270 - Michel Heeremans14
Permeability will not be addressed in the course
-
8/11/2019 GEO4270 _ RESEVAL
15/51
How can we measure these parameters?
-
8/11/2019 GEO4270 _ RESEVAL
16/51
Water Saturation
Water saturation can be measured with the help of:Resistivity (R), n. [Formation Evaluation]
The ability of a material to resist electrical conduction. It is the.
resistivity is a property of the material, whereas the resistancealso depends on the volume measured.
!! Hydrocarbons are resistive while formation water isconductive !!
10/14/2008 GEO4270 - Michel Heeremans16
-
8/11/2019 GEO4270 _ RESEVAL
17/51
Water Saturation
The Resistivity of a formation is dependent on: Presence of Formation water / Hydrocarbons
Salinity of Formation water
Temperature of Formation water Volume of water-saturated pore space
Geometry of the pore space
Mor holo and s ecies of cla minerals
10/14/2008 GEO4270 - Michel Heeremans17
-
8/11/2019 GEO4270 _ RESEVAL
18/51
Water Saturation
Archies e uation Archie, G.E., 1942
Relation between Water Saturation and Resistivity
Sw = Water saturation
F = Formation Resistivit Factor a/ m :
ow RFR Porosity () Tortuosity factor (a)
tt
wRR Cementation factor (m)
Rw = Resistivity of the formation water Rt = Resistivity of a rock with HC, i.e.
true resistivity
= -
10/14/2008 GEO4270 - Michel Heeremans18
o saturated rock
-
8/11/2019 GEO4270 _ RESEVAL
19/51
Porosity
Direct measurements Conventional coring
Sidewall coring
Indirect Measurements Sonic Log
Density Log
Neutron Lo
10/14/2008 GEO4270 - Michel Heeremans19
-
8/11/2019 GEO4270 _ RESEVAL
20/51
Porosity
Sonic Log, n. [Geophysics]A type of acoustic log that displays traveltime of P-waves versus depth
(recorded in interval transit time (t), s/ft, which is the reciprocal of.
the wellbore. The tool emits a sound wave that travels from the source to theformation and back to a receiver.
og sym o :
10/14/2008 GEO4270 - Michel Heeremans20
-
8/11/2019 GEO4270 _ RESEVAL
21/51
Porosity
Dependent on lithology and porosity
Sonic porosity derived by:
sonic = sonic derived porosity
Cptt matrixf
matrix
sonic
log
=
tmatrix = interval transit time of the matrix (table)
tlog = interval transit time of the formationtf= interval transit time of the fluid in the wellbore (fresh mud = 189; salt mud = 185)C = com action factor =
R1
R2100
Ctsh
tsh = interval transit time for adjacent shale C = a constant, normally 1.0
10/14/2008 GEO4270 - Michel Heeremans21
-
8/11/2019 GEO4270 _ RESEVAL
22/51
Porosity
Density Log, n. [Formation Evaluation]A well log that records formation density. The logging tool consists of agamma-ray source (e.g., Cs137) and a detector shielded from the source sothat it records backscattered gamma rays from the formation (Comptonscattering). The backscattering depends on the electron density of theformation, which is roughly proportional to the bulk density.
Log symbol: RHOB, DEN
10/14/2008 GEO4270 - Michel Heeremans22
-
8/11/2019 GEO4270 _ RESEVAL
23/51
Porosity
Density Log1. Identify evaporite minerals
2. Detect gas-bearing zones
3. Determine hydrocarbondensity
4. Evaluate shaly sand reservoirs
and complex lithologies
10/14/2008 GEO4270 - Michel Heeremans23
-
8/11/2019 GEO4270 _ RESEVAL
24/51
Porosity
DRHO is a correction curve, if DRHO >0.20 gm/cc the RHOB curve is invalid
RHOB (formation bulk density) is afunction of matrix density, porosity anddensity of the fluids in the pores,
ere ore:
bmatrix
fmatrix
den
with:
den = density derived porosity
matrix = matrix density (table)b = orma on u ens yf= fluid density
10/14/2008 GEO4270 - Michel Heeremans24
DRHO = 0.20 og sym o :
-
8/11/2019 GEO4270 _ RESEVAL
25/51
Porosity
Neutron Porosity, adj. [Formation Evaluation]
Referring to a log of porosity based on the effect of the formation on fast neutrons emitted.neutrons. Since hydrogen is found mainly in the pore fluids, the neutron porosity logresponds principally to porosity. However, the matrix and the type of fluid also have aneffect.
Scaled in equivalent limestone porosity units, i.e. low NPHI values represent limestone
Log symbol: NPHI, CN
y rogen n pore wa er, y rocar ons an s a es n quar z, e spars ancarbonates
10/14/2008 GEO4270 - Michel Heeremans25
-
8/11/2019 GEO4270 _ RESEVAL
26/51
Correlation Logs
Gamma Ray Log A well log of the natural
formation radioactivity level
The log mainly reflects claycontent because clay
con a ns e ra oac ve
isotopes of K, U and Th
with the SP-log
10/14/2008 GEO4270 - Michel Heeremans26
-
8/11/2019 GEO4270 _ RESEVAL
27/51
Correlation Logs
Spontaneous Potential Log
A record of Direct Current (DC)voltage (or Potential) that develops
moveable electrode in the well anda fixed electrode located at the
Used to Correlation
Detect boundaries of permeable beds
Determine formation-water resistivity (Rw)
Determine the volume of shale in permeablee s
Detection of hydrocarbons by the suppression ofthe SP curve
10/14/2008 GEO4270 - Michel Heeremans27
GR-log
-
8/11/2019 GEO4270 _ RESEVAL
28/51
SEISMIC INTERPRETATION
Reservoir Identification
Seismic Attributes
GEO4240
or summary
-
8/11/2019 GEO4270 _ RESEVAL
29/51
Reservoir Identification
Phase Polarity
Amplitude
Spatial Extent
Frequency
helping to identify HC e oc y
AVO
10/14/2008 GEO4270 - Michel Heeremans29
-
8/11/2019 GEO4270 _ RESEVAL
30/51
Reservoir Identification
Minimum Phase
RC+ RC-
Zero Phase
RC+ RC-
10/14/2008 GEO4270 - Michel Heeremans30
-
8/11/2019 GEO4270 _ RESEVAL
31/51
Reservoir Identification
10/14/2008 GEO4270 - Michel Heeremans31
-
8/11/2019 GEO4270 _ RESEVAL
32/51
Seismic Attributes
An attribute is a derivative of a basic seismic measurement e or zon an orma on a r u es ava a e see g. -1) are not independent of each other but simply differentways of presenting and studying a limited amount of basicinformation
That basic information is time, amplitude, frequency and
classification
Seismic attributes may be defined as all the information,
or by logical or experience based reasoning. (Taner, 1998)
10/14/2008 GEO4270 - Michel Heeremans32
-
8/11/2019 GEO4270 _ RESEVAL
33/51
Seismic Attributes
Time-derived attributes provide structural information-information
Frequency-derived attributes are not yet well understood but there is-
stratigraphic and reservoir information Attenuation is not used today, but there is a possibility that in the futureit will ield information on ermeabilit
Most attributes are derived from the normal stacked and migrated data
volume but variations of basic measurements as a function of an le ofincidence (and hence source to receiver offset) provides a further sourceof information. The principal examples of these pre-stack attributes is
AVO
10/14/2008 GEO4270 - Michel Heeremans33
-
8/11/2019 GEO4270 _ RESEVAL
34/51
Seismic Attributes
10/14/2008 GEO4270 - Michel Heeremans34
-
8/11/2019 GEO4270 _ RESEVAL
35/51
Seismic Attributes
10/14/2008 GEO4270 - Michel Heeremans35
-
8/11/2019 GEO4270 _ RESEVAL
36/51
Seismic Attributes
Time Slice!
10/14/2008 GEO4270 - Michel Heeremans36
-
8/11/2019 GEO4270 _ RESEVAL
37/51
Property Modeling (or Reservoir Modeling)
It is better to have a model of uncertainty
an an us on o rea y
Andre Journel
-
8/11/2019 GEO4270 _ RESEVAL
38/51
Introduction
Goal of Property modeling: Capture geology and build realistic property models
Goal of Reservoir modeling: Predicting rock properties at unsampled locations and forecasting the future
,
12002)
y use o eos a s cs
10/14/2008 GEO4270 - Michel Heeremans38
-
8/11/2019 GEO4270 _ RESEVAL
39/51
Why create a realistic reservoir property model?
We are making big decisions based on limited data Maximize the usage of all information optimise production
Correct upscaling of logs and a proper facies interpretation
is important Reservoir properties are critical factors affecting production
10/14/2008 GEO4270 - Michel Heeremans39
-
8/11/2019 GEO4270 _ RESEVAL
40/51
Geostatistics
Geostatistics is a branch of applied statistics that placesemp as s on: The geological context of the data
The spatial relationship between the data
Data measured with different volumetric support and precision
us ness ee : ma e e es poss e ec s on n e ace ouncertainty. Uncertainty exists because of our incomplete
knowled e of a dataset alwa s incom lete data . One ofthe biggest uncertainties is the numerical description of thesubsurface
10/14/2008 GEO4270 - Michel Heeremans40
-
8/11/2019 GEO4270 _ RESEVAL
41/51
Examples of Geostatistics
Analysis of variables in space Samples located close to each other are probably more
similar than samples located far from each other
The spatial coordinates of the observed samples are builtinto the statistic formulas
Examples: Gold content in ore (ppm)
Reservoir sandstone bed thickness (meter/feet)
10/14/2008 GEO4270 - Michel Heeremans41
-
8/11/2019 GEO4270 _ RESEVAL
42/51
Incorporate the Maximum Amount of Data
Well data Seismic data Production Outcrops Other geological studies
Integrated study Structure horizon, fault
Deterministic
information
Stratigraphic correlation
Facies images Framework
Statistical
information
Conceptual
information
e men o og ca mo e
Facies description
Connectivity
s ogram
Variogram
Correlation
Trend
Variation
10/14/2008 GEO4270 - Michel Heeremans42
-
8/11/2019 GEO4270 _ RESEVAL
43/51
Sequential Approach to Property Modeling
1. Defining the geometry and stratigraphic layering of the reservoir interval to bemodeled Involves the development of a conceptual model for the major architecture and continuity of
facies, porosity and permeability witihin each layer
2. The facies rock types are modeled by either (1) cell-based or (2) object-based
3. The porosity is modeled on a by-facies basis before permeability because thereare more reliable porosity data available
4. The 3-D models of permeability are constrained to the porosity, facies andayer ng prev ous y es a s e
5. Multiple equally likely realizations are created by repeating the entire process Each realization is equally likely to be drawn; however, some realizations are more similar to
others, hence their class has higher probability6. These models are input to a simulator or visualized and used to aid in decision
making
10/14/2008 GEO4270 - Michel Heeremans43
-
8/11/2019 GEO4270 _ RESEVAL
44/51
Tampen Spur
Introduction
-
8/11/2019 GEO4270 _ RESEVAL
45/51
F
Location
B
H
10/14/2008 GEO4270 - Michel Heeremans45
-
8/11/2019 GEO4270 _ RESEVAL
46/51
Facts
Discovery well: 33/12-1
Discovery Year: 1974
. . Total production of saleable products 04.2007: 633.786214 mill. Sm3 o.e.
Recoverable reserves:
3 .
Gas: 25.70 bill Sm3
NGL: 11.40 mill tonne
a o r r o uc on
35
40
45
50
10
15
20
25
30
Sm3
0
5
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
Year
Oil [mill Sm3] Gas [bill Sm3] Sm3o.e. [mill] Water [mill Sm3]
10/14/2008 GEO4270 - Michel Heeremans46
NGL: Natural Gas Liquids, incl. propane, butane, pentane, hexane and heptane, but not methane and ethane
1 tonne NGL: 1.9 Sm3 o.e.
-
8/11/2019 GEO4270 _ RESEVAL
47/51
Stratigraphy
10/14/2008 GEO4270 - Michel Heeremans47From: Evans et al, 2003, Millenium Atlas
-
8/11/2019 GEO4270 _ RESEVAL
48/51
Cross Section
10/14/2008 GEO4270 - Michel Heeremans48
-
8/11/2019 GEO4270 _ RESEVAL
49/51
GEO4270 Prospect Evaluation
IMPORTANT! PETREL is just a tool which helps you with your interpretation and
modeling
This exercise is meant for leanin reservoir identification reservoir
evaluation and reservoir modeling
The results depend completely on your own interpretationan e accuracy o e ava a e a a
10/14/2008 GEO4270 - Michel Heeremans49
-
8/11/2019 GEO4270 _ RESEVAL
50/51
Important links
http://www.npd.no/English/Produkter+og+tjenester/Fakta+og+statistikk/fakta-start.htm (Norway Wells)
http://www.og.dti.gov.uk/information/wells.htm (UK Wells)
10/14/2008 GEO4270 - Michel Heeremans50
-
8/11/2019 GEO4270 _ RESEVAL
51/51
References
Asquith, G. and Krygowski, D. (2004). Basic Well LogAnalysis
Brown, A. (2004). Interpretation of Three-Dimensional
Seismic Data
Deutsch, C. (2002). Geostatistical Reservoir Modeling
Evans, D. et al. (2003). Millenium Atlas
Schlumberger (2006). Petrel Seismic to Simulation Software
roper y o e ng ourse, v.
10/14/2008 GEO4270 - Michel Heeremans51