渤南洼陷古近系深层有效储层控制因素研究

Controlling Factors on the Paleogene Deep Effective Reservoirs in the Bonan Sag

依据试油、物性、压汞等资料,利用多种方法求取了渤南洼陷古近系深层有效储层物性下限与埋藏深度的定量函数关系。在此基础上,以孔隙度差值和渗透率差值作为对比参数,探讨了沉积作用、地层压力和成岩作用对渤南洼陷古近系深层有效储层的控制作用。湖底扇中扇辫状水道和扇三角洲前缘地层压力为中强超压、处于中成岩A1期为有效储层发育的有利因素,而近岸水下扇和冲积扇地层压力为常压和弱超压、处于中成岩B期和晚成岩期为有效储层发育的不利因素。总体上,沉积相带是形成优质有效储层的主要控制因素,而地层压力对有效储层发育的控制作用强于成岩作用。

Based on the data of oil tests,physical properties and mercury penetration,several methods were used to establish a quantitative functional relationship between the geophysical property cutoff and the burial depth of the Paleogene deep effective reservoirs in Bonan sag.On this basis,this study discussed the controlling functions of sedimentation,formation pressure and diagenesis on the Paleogene deep effective reservoir in Bonan sag,regarding the porosity and permeability differences as comparison parameters.The favorable factors to the development of deep effective reservoirs are braided channels of middle sublacustrine fan and fan delta front facies,middle-strong overpressure,and A1 sub-stage of the middle diagenesis.While near-shore subaqueous fan and alluvial fan facies,normal pressure and weak overpressure,late diagenesis and B sub-stage of the middle diagenesis are unfavorable factors to the development of deep effective reservoirs.In general,sedimentary facies are the main controlling factor to the development of deep effective reservoirs,and the controlling function of formation pressure to the deep effective reservoirs is stronger than diagenesis.