Geometric models of listric normal faults and rollover folds

Journal Article · Tue Oct 01 04:00:00 EDT 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5814724

Dula, Jr, W F ^[1]

---

1. ARCO Oil and Gas Co., Plano, TX (United States)

Existing geometric models allow master fault shapes to be constructed, given the shape and heave or displacement of a deformed marker horizon in the hanging wall. These models assist in projecting normal faults to depth where the fault geometry is poorly constrained by available seismic data. Currently, it is unclear which model best predicts the actual relation between rollover and fault geometries. To address this deficiency, the relative accuracies of the constant-heave, constant-displacement, constant-bed-length, slip-line, and inclined-shear constructions are evaluated using clay model analogs and seismic examples. Each of the geometric models predicts a different fault shape and depth to detachment for the same rollover shape, because different hanging-wall deformation mechanisms are assumed. For sub-surface examples, the inclined-shear model and the constant-displacement model predict fault trajectories that are the most similar to the positions and shapes of the master-fault segments interpreted from offshore Norway and Gulf of Mexico seismic lines. The shear angle required in the inclined-shear model can often be estimated from the orientation of minor faults in the hanging wall. The shear angle may also be determined through iterative modeling in which the shear angle is systematically varied, and the resultant model fault shape is compared to the shape of the shallow segment of the master fault interpreted from the seismic record.

• OSTI ID: 5814724
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:10; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200 -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000* -- Geosciences
ATLANTIC OCEAN
CARIBBEAN SEA
DEVELOPED COUNTRIES
EUROPE
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
GEOMETRY
GEOPHYSICAL SURVEYS
GULF OF MEXICO
MAPPING
MATHEMATICS
NORWAY
OFFSHORE SITES
RESERVOIR ROCK
SCANDINAVIA
SEAS
SEISMIC SURVEYS
SIMULATION
SURFACE WATERS
SURVEYS