High-resolution stratigraphic forward modeling: A case study of the lower-middle San Andres formation, Permian basin

Conference · Wed Sep 01 00:00:00 EDT 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7134332

Shuster, M W ^[1]; Childers, D W ^[2]

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1. KSEPL (Shell Research), Rijswijk (Netherlands)
2. Shell Western Exploration and Production Inc., Houston, TX (United States)

This study has attempted to calibrate Shell's two-dimensional (2-D) basin modeling program as an exploration tool by simulating the stratigraphy of a mixed carbonate/clastic third-order depositional sequence. The lower-middle San Andres Formation was selected because available log, core, and outcrop data from the Northwest Shelf area, Permian basin, provided an excellent calibration set. A regional stratigraphic cross section from the Cato-Chaveroo to the Wasson fields was constructed delineating lithology and porosity distribution. Approximately 10 shoaling-upward depositional cycles were interpreted. A higher frequency, five-in-one cyclicity was also interpreted based on core and outcrop data. The observed stratigraphy was simulated using a composite eustasy consisting of third-order (2,000,000 yr), fourth-order (100,000 yr), and fifth-order (20,000 yr) sinusoids each at five-meter amplitudes. Subsidence input was constrained by back-stripped tectonic subsidence curves calculated from well data. Sedimentation parameters were interactively derived. New empirically based algorithms were used to model Dunham lithofacies, environmental facies, and sabkha anhydrite distribution. Synthetic log and 2-D synthetic seismic profiles were constructed from the simulation output. The simulation results suggest that (1) relative sea level is the dominant control on the observed depositional cyclicity, (2) the distribution of regional seal facies (anhydrite) reflects falling sea level and prolonged exposure, (3) limestone-dolomite trends on the shelf are grossly related to environment and (4) the distribution of grainstones and packstones (potential reservoirs) occurs as fourth- and fifth-order offlapping and aggradational pods. The synthetic log signatures compared to [open quotes]real[close quotes] logs substantiate the interpreted depositional cyclicity, but also point out the difficulty in interpreting high-order cycles based on log data alone.

• OSTI ID: 7134332
• Report Number(s): CONF-9310237-; CODEN: AABUD2
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:9; Conference: American Association of Petroleum Geologists (AAPG) mid-continent section meeting, Amarillo, TX (United States), 10-12 Oct 1993; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
GEOLOGIC MODELS
CALIBRATION
SEDIMENTARY BASINS
SIMULATION
STRATIGRAPHY
EXPLORATION
LITHOLOGY
PERMIAN BASIN
POROSITY
RESERVOIR ROCK
SEA LEVEL
SEDIMENTARY ROCKS
SEDIMENTATION
TECTONICS
GEOLOGIC STRUCTURES
GEOLOGY
LEVELS
PETROLOGY
ROCKS
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
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& Exploration