Monitoring compaction and compressibility changes in offshore chalk reservoirs

Journal Article · Tue Mar 01 04:00:00 EST 1994 · SPE Formation Evaluation (Society of Petroleum Engineers); (United States)

DOI:https://doi.org/10.2118/23142-PA· OSTI ID:7306198

Dean, G; Hardy, R ^[1]; Eltvik, P ^[2]

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1. Amerada Hess Ltd., London (United Kingdom)
2. Amerada Hess, Norge (Norway)

Some of the North Sea's largest and most important oil fields are in chalk reservoirs. In these fields, it is important to measure reservoir compaction and compressibility because compaction can result in platform subsidence. Also, compaction drive is a main drive mechanism in these fields, so an accurate reserves estimate cannot be made without first measuring compressibility. Estimating compaction and reserves is difficult because compressibility changes throughout field life. Installing of accurate, permanent downhole pressure gauges on offshore chalk fields makes it possible to use a new method to monitor compressibility -- measurement of reservoir pressure changes caused by the tide. This tidal-monitoring technique is an in-situ method that can greatly increase compressibility information. It can be used to estimate compressibility and to measure compressibility variation over time. This paper concentrates on application of the tidal-monitoring technique to North Sea chalk reservoirs. However, the method is applicable for any tidal offshore area and can be applied whenever necessary to monitor in-situ rock compressibility. One such application would be if platform subsidence was expected.

• OSTI ID: 7306198
• Journal Information: SPE Formation Evaluation (Society of Petroleum Engineers); (United States), Journal Name: SPE Formation Evaluation (Society of Petroleum Engineers); (United States) Vol. 9:1; ISSN 0885-923X; ISSN SFEVEG
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ATLANTIC OCEAN
CARBONATE ROCKS
COMPRESSIBILITY
GEOLOGIC DEPOSITS
LIMESTONE
MECHANICAL PROPERTIES
MINERAL RESOURCES
NORTH SEA
OFFSHORE OPERATIONS
PETROLEUM DEPOSITS
PRESSURE MEASUREMENT
RESERVOIR PRESSURE
RESERVOIR ROCK
RESOURCES
ROCKS
SEAS
SEDIMENTARY ROCKS
SURFACE WATERS