Page 244 - Origin and Prediction of Abnormal Formation Pressures
P. 244
216 V.I. ZILBERMAN, V.A. SEREBRYAKOV, M.V. GORFUNKEL, G.V. CHILINGAR AND J.O. ROBERTSON JR.
Geologic cross-section
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Isopach map (J1)
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Legend:
[~:1 Stratigraphic boundaries
~ Indicator sequence
[7] Isopachs of indicator sequence ~ Gas accumulation with AHFP
Faults ~ Massive gas accumulation
Salt plugs ~ Zone of possible AHFP
Fig. 9-4. Direct delineation of AHRP zones in the near-plug area. (After Zilberman and Chernyakov, 1981.)
The weakness lies in the delineation of the salt plug, which is the boundary between
the accumulation and the AHFP zone. As mentioned above, the seismic survey is
not capable to accurately delineate the salt plugs. Errors in locating the boundaries
result in poor well locations. As an example, in Western Krestischensk gas condensate
accumulation, five appraisal wells and one development well have been drilled without
