PASSIVE MODE SALT DOES NOT ACTIVELY DEFORM SEDIMENT. MOST FEATURES ARE ATTRIBUTED TO SALT...

PASSIVE MODE

SALT DOES NOT ACTIVELY DEFORM SEDIMENT.

MOST FEATURES ARE ATTRIBUTED TO SALT

WITHDRAWAL.

ACTIVE MODE

SALT ACTIVELY PUSHES SEDIMENT COVER

OUT OF THE WAY AS I TRIES TO RISE TO THE

SAE FLOOR.

VERTICAL MOTION

FORCE

• DEFFERENTIAL LOADING OR DENSITY DIFFRENCES

RESULTANT

SALT DOMES

SALT DIAPIRS

SHALE DOMES

FAULT RECOGNITION

• ABRUPT TERMINATION OF REFLECTION

• OFFSET OF A REFLECTION

• DIFRACTION

• CHANGE IN RELECTION PATTERN

• CHANGE IN DIP

• CHANGE IN FREQUENCY

• DISTORTION OF DATA BELOW FAULT

- VELOCITY ANOMALY

- SHADOW ZONE

• REFLECTION FROM FAULT PLANE

KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 1/10

NORMAL FAULTS

• HORST AND GRABEN

• TITLED BLOCKS

• HIGH ANGLE SAMPLE FAULTS

• UNCONFORMITY ON PRE-FAULT SEDIMENTS

• STRUCTURES ANGULAR IN CROSS SECTION

• FAULTS DIP TOWARD UPLIFT

• DRAPE COMMON

• DRAG ON DOWNSIDE OF FAULTS

• FAULTS RELAY, ZIG-ZAG IN MAP VEIW

• DIFRACTIONS ON DOWNSIDE OF FAULTS

• OFTEN HIDDEN BY OVERLYING STRUCTURE


UPTHRUST FAULTS

• FAULT FORMS ZONE OF INTENSE DEFORMATION

• BLOCKY AWAY FROM FAULT

• FAULT IS HIGH ANGLE - MAY SPLIT OUT

• ONE PERIOD OF MOTION

• STRUCTURES PARALLEL FAULTS

• STRUCTURES ANGULAR IN CROSS SECTION

• GRAVITY AND MAGNATIC EXPRESSION PROBABLE


EN ECHELON FOLDS AND FAULTS

• STRUCTURES AT ANGLE TO THRUOGH-GOING FAULTS

• STRUCTURES ASYMMETRICAL

• ANTICLINES PREDOMINATE

• FAULT-STRUCTURE RELATION CHANGES LINE TO LINE

• FAULTS VERY HIGH ANGLE

• FAULTS SPLY UPWARD INTO SHALLOWER BEDS

• THROUGH-GOING FAULT GENERALLY NOT SEEN

• EXTENSIONAL FAULTS MAY DEVELOP ON CRESTS

• GRAVITY AND MAGNETICS MAY SHOW


FLOWER STRUCTURES

• PARALLEL THROUGH-GOING FAULT

• DIE OUT DOWNWARD

• COMPOSED OF COMPLEX PATTEN OF ABERRANT WEDGES

• FAULTS NEARLY VERTICAL BUT SPLAY OUT UPWARD

• STRUCTURE -FAULT RELATION CHANGES LINE TO LINE

• STRUCTURING DIES UOT ABRUPTLLY

• ANTICLINES PREDOMINATE

• DIFRACTIONS COMMON

•GRAVITY AND MAGNATICS MAY SHOW


FOLD AND THRUST BELT ROLES

• COMPRESSIONAL AND DETACHED

• DOMINANT VERGENCE DIRECTION

• OUTWARD DEVELOPMENT OF THRUST SHEEETS

• THRUSTS OUT UPSECTION IN DIRECTION OF TRANSPORT

• THRUST BRING OLDER ROCKS OVER YOUNGER ROCKS

• EXISTENCE OF PREFERRED DETACHMENTS IN SECTION

• EXISTENCE OF A REGOINAL TECTONIC LEVEL


COMPATIBILITY WITH GRAVITY DATA

A GEOLOGICAL MODEL THAT IS COMPATIBLE WITH

THE OBSERVED GRAVITY DATA IS POSSIBLY CORRECT.

A GEOLOGICAL MODEL WHOSE GRAVITY EXPONSE

DISAGREES WITH THE OBSERVED GRAVITY DATA IS

DEFINITELY WRONG.


SALT STRUCTURES

INTRODUCTION

TYPES OF STRUCTURES AND TRAPS

1. CLASSIFICATION

2. VARIATIONS DUE TO GROWTH HISTORY

3. DETACHED NORMAL FAULTS

SEISMIC INTERPRETATION

1. REFLECTION QUALITY

2. INTERNAL SEISMIC CHARACTER OF SALT

3. WHAT TO USE WITHOUT SALT REFLECTION

4. DOME WITH SHADOW DOME

5. INTERPRETATION PROBLEMS


SALT FEATUREIM

PL

AC

EM

EN

T P

RO

CE

SS

ACTIVE

PASSIVE

PIERCEMENT

NON PIERCEMENT HORIZANTAL

ACTIVE PILLOW OR ANTICLINE

PASSIVE (RESIDUAL) PILLOW OR ANTICLINE

ACTIVE (1-SIDED?)

DOME OR WALLSILL INTRUSIVE

PASSIVE DOME OR

WALL

GLICIER (EXTRUSIVE)


SUMMARY OF HYDROCARBONE TRAPS RELATED TO SALT

PILLOW

• A TRAP IS A DOUBLY-PLUNGING ANTICLINE

• STRTIGRAPHIC COMPLICATIONS ONLAP,

LOSS OF SECTION ON TO CREST

VARATION BETWEEN FAULT BLOCKS

• STRUCTURAL COMPLICATIONS COMPLEX

TRAP SEGMENTATION BY FAULTS

FAULT SEAL



SALT STRUCTURES

PASSIVE MODE SALT DOES NOT ACTIVELY DEFORM SEDIMENT. MOST FEATURES ARE ATTRIBUTED TO SALT...

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