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Geoscience ›› 2012, Vol. 26 ›› Issue (3): 540-546.

• Petroleum geology • Previous Articles     Next Articles

Restoration of Paleoformation Pressure of Shale in the 3rd Member ofShahejie Formation and Its Application in Eastern Slope of Jinxian1-1 Low Uplift, Liaodong Bay Fault Depression

 CHEN  Kai-1, LIU  Shen-1, SHU  Wen-Ai-1, ZHOU  Xin-Fu-2, ZHANG  Rong-Hui-3   

  1. 1 State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing102249, China;2 Tianjing Branch of CNOOC Limited, Tianjin300452, China;3 No.8 Oil Production Company of Changqing Oilfield Company,PetroChina,Xian, Shaanxi710021,China)
  • Received:2011-12-09 Revised:2012-02-08 Online:2012-06-07 Published:2012-06-14

Abstract:

Overpressure in shale is the main force for hydrocarbon expulsion and primary migration, and its changes are always recorded by the evolution of shales porosity. Firstly, the evolution module of shales porosity in undercompacted shale was set up through compaction section reflecting the characteristic of compaction at present. And then the method of “regressive extrapolation” modeling was used to restore evolution porosity increment of paleoporosity shale in hydrocarbon accumulation period. Based on this restoration, the total porosity of undercompacted shale could be figured out by the evolution module of shales porosity. Finally, modified Phillippone formula could be used to calculate paleoformation pressure of source rocks and to recover evolution of paleoformation pressure. The result showed that overpressure of source rock of the 3rd Member of Shahejie Formation enhanced gradually from south to north in eastern slope of Jinxian 1-1 low uplift, and the change regular of paleoformation pressure was important for hydrocarbon migration and profitable target selection.

Key words: the eastern slop of Jinxian 1-1 low uplift, the 3rd Member of Shahejie Formation, source rock, mudstone paleo porosity, shale paleo formation pressure