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Rock compressibility, compaction, and subsidence in a high-porosity Chalk Reservoir

Journal Article · · Journal of Petroleum Technology; (USA)
OSTI ID:5537394
 [1]; ; ;  [2];  [3]
  1. Amoco Norway Oil Co. (US)
  2. Amoco Production Co., Tulsa, OK (USA)
  3. Danish Geotechnical Inst. (US)

A case study of the North Sea Valhall chalk reservoir demonstrates the significant impact that rock compressibility can have on field performance. Porosity reduction, reservoir interval compaction, and seabed subsidence have been observed in conjunction with reservoir pressure depletion. Full-diameter samples from a recently cut core of the unconsolidated high-porosity chalk were subjected to a series of uniaxial-strain experiments to determine compaction and PV compressibility. The laboratory measurements were corrected to field stress rates and pressure, and porosity-dependent rock-compressibility curves were developed. The uniaxial compaction data were used both in a reservoir model to recognize the significant additional reservoir energy resulting from the lithic drive of large-scale rock compaction and in a subsidence model to predict the impact of reservoir depletion on seabed displacements.

OSTI ID:
5537394
Journal Information:
Journal of Petroleum Technology; (USA), Journal Name: Journal of Petroleum Technology; (USA) Vol. 41:7; ISSN JPTJA; ISSN 0022-3522
Country of Publication:
United States
Language:
English

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