Paleomagnetic core-orientation for characterizing reservoir anisotropy: Case histories from fractured reservoirs in Abu Dhabi and Venezuela

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7078885

Alstine, D.R. van; Butterworth, J E ^[1]; Willemse, E J.M.

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1. Applied Paleomagnetics, Inc., Redmond, WA (United States)

Over the past decade, the authors have tested and refined the paleomagnetic core-orientation technique, they first applied on the U.S. Department of Energy's Multiwell Experiment in the early 1980s. Paleomagnetic orientation accuracy within 5{degree} is routinely achievable, as demonstrated in over 100 tests against dipmeter, seismic, borehole televiewer, and mechanical core-orientation (conventional multishot and MWD) techniques. These tests reveal that mechanical core-orientations commonly suffer from torques acting on downhole equipment and on the core. In contrast, the paleomagnetic core-orientation technique is not prone to downhole mechanical problems, uses no rigtime, is cost-effective, and can selectively orient individual core pieces, including ASR and DSCA samples. Accurate paleomagnetic orientations can be obtained even from cores drilled decades ago. In Abu Dhabi, paleomagnetically-oriented 10-year-old slabbed cores from Habshan and Dukhan carbonates yield fracture patterns consistent with the geologic structure in the Asab and Sahil fields. In Venezuela, paleomagnetic orientation of fresh and decade-old archived cores of Cogollo limestones and La Luna black shales yield fracture and bedding directions consistent with dipmeter data and outcrop observations around Lake Maracaibo. Paleomagnetic core-orientation permits access to the vast resource of reservoir-anisotropy data in previously unoriented cores in storage throughout the world. Paleomagnetic core-orientation is a versatile technique with proven accuracy, not only in vertical wells, but also in slant holes and horizontal wells.

• OSTI ID: 7078885
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
RESERVOIR ROCK
PALEOMAGNETISM
UNITED ARAB EMIRATES
PETROLEUM DEPOSITS
VENEZUELA
ANISOTROPY
DRILL CORES
FRACTURED RESERVOIRS
WELL DRILLING
WELL LOGGING
ASIA
DEVELOPING COUNTRIES
DRILLING
GEOLOGIC DEPOSITS
LATIN AMERICA
MAGNETISM
MINERAL RESOURCES
RESOURCES
SOUTH AMERICA
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences