Diagenetic effects of high thermal overpressure in the Yinggehai basin, offshore South China Sea
There are unique temperature-pressure characteristics in the Yinggehai basin, so its reservoir diagenesis has some unusual processes and traits. Through comparing two types of overpressure systems (selfsource type and conduction type) that have been confirmed by study of cores and logs, this paper illustrates the impacts of high geothermal gradients and overpressure as the conditions for water-rock reactions on diagenesis.The process of diagenesis and its effects on reservoirs are also discussed. The results show that: 1 high geothermal gradients result in the easy dissolution of some minerals, thus resulting in the decreases of sandstone porosity, and creation of secondary porosity; 2 self-source overpressure can prevent parts of the original porosity from compacting, which sometimes results in high porosity in deep reservoirs; 3 fluids expulsion causes lots of cracks which effectively increase reservoir permeability, and hot fluid from depth can accelerate the process of diagenesis in overlying strata.
T.Jiang X.N.Xie X.F.Liu X.B.Du
Faculty of Earth Resources, China University of Geosciences, Wuhan, P.R.China
国际会议
第十二届水-岩相互作用国际研讨会(P0roceedings of the 12th International Symposium on Water-Rock Interaction)
昆明
英文
213-216
2007-07-31（万方平台首次上网日期，不代表论文的发表时间）