Post on 20-Jan-2016
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 1/10
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 2/10
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 3/10
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 4/10
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 5/10
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.
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 6/10
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 7/10
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)
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 8/10
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
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 9/10
KFUPM/ES/Geophysics/Seismic Interpretation/Al-Ghamdi # 10/10
SALT STRUCTURES