车镇凹陷古近系深层碎屑岩有效储层物性下限及控制因素

综合运用物性、试油、压汞等资料，分别利用分布函数曲线法、测试法、试油法、束缚水饱和度法以及最小有效孔喉半径法，求取了车镇凹陷古近系深层有效储层物性下限，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深层有效储层发育的控制作用。车镇凹陷古近系深层碎屑岩有效储层孔隙度下限与深度的对数呈线性函数关系，渗透率下限与深度呈指数函数关系。三角洲前缘水下分流河道、河口坝微相砂体有效储层最发育、孔隙度差值和渗透率差值较好，而湖底扇、近岸水下扇、扇三角洲以及冲积扇砂砾岩体有效储层发育较少、孔隙度差值和渗透率差值较差；中强超压储层的有效储层百分含量、孔隙度差值和渗透率差值均好于常压—弱超压储层；中成岩A1期储层的有效储层百分含量、孔隙度差值和渗透率差值均好于中成岩A2、中成岩B期储层。总体上，沉积相带是深层有效储层发育的最主要控制因素，异常高压对有效储层发育的控制作用强于成岩作用，成岩作用对有效储层的影响受沉积相带和异常高压的控制，原始储集性能好且受异常高压保护的储层易于受溶解作用的改造形成优质有效储层。

Lower Property Limit and Controls on Deep Effective Clastic Reservoirs of Paleogene in Chezhen Depression

Based on the comprehensive application of properties, oil production test, and mercury injection data, the lower property limit of deep clastic reservoirs of Paleogene in Chezhen depression was determined by applying distribution function curve method, testing method, production test method, irreducible water saturation method, and the lowest effective pore throat radius method, and the influence factors were analyzed. On this basis, regarding the porosity and permeability difference as comparison parameters, the controlling actions of which sedimentation, formation pressure and diagenesis played on the deep effective reservoir were researched. The porosity lower limit and log depth are linear relationship, and the lower permeability limit and depth are exponential relationship. Deltaic front subaqueous distributary channel and mouth bar develop most effective reservoir, and porosity difference and permeability difference are well. while sublacustrine fan, nearshore subaqueous fan, fan delta and alluvial fan sand conglomerate develop less effective reservoir, and porosity difference and permeability difference are worse. The effective reservoir percentage content, porosity difference and permeability difference of middle and strong overpressure reservoirs are better than that of normal pressure and weak overpressure reservoirs. The effective reservoir percentage content, porosity difference and permeability difference of reservoirs on the middle diagenetic stage A1 are better than that of the reservoirs on the middle diagenetic stage A2 and B. In general, sedimentary facies is the main controlling factor on the development of deep effective reservoir, and the controlling action of overpressure on the deep effective reservoirs is stronger than diagenesis. The influence of diagenesis on the deep effective reservoirs is controlled by both sedimentary facies and overpressure. The reservoirs with high primary porosity and permeability protected by overpressure are dissolved easily to be good effective reservoirs.