Characteristics of Deep Abnormal High Pressure and its Controlling on Hydrocarbon Accumulation in Zhanhua Sag
Study on abnormal pressure of sedimentary basin is of great significance. According to the ultrasonic time difference method and measured practical data, some sectional and planar pressure distribution of Zhanhua Sag are obtained while most belong to overpressure, and the pressure distribution and the formation mechanism of high pressure are also analyzed. It is showed that the pore fluid pressure of Es3 and the upper part of Es4 members are higher in Bonan subsag and Gubei subsag and the distribution of abnormal high pressure reached a maximum at the early Es3. The disequilibrium compaction, hydrocarbon generation and some clay mineral dehydration are suggested to contribute to the formation of normal high pressure, including the rapid deposition as one of the most key factor. The lower part of Es3 and Es4 themselves within the deep high pressure system, as good lithologic reservoirs, can transport oil to the upper formation by episodic release to form allochthonous atmospheric hydrocarbon reservoirs.
Q. H. Shi et al., "Characteristics of Deep Abnormal High Pressure and its Controlling on Hydrocarbon Accumulation in Zhanhua Sag", Applied Mechanics and Materials, Vol. 628, pp. 376-382, 2014