砂岩机械压实与物性演化成岩模拟实验初探  

Preliminary Discussion of Simulation Experiments on the Mechanical Compaction and Physical Property Evolution of Sandstones

作　　者：操应长 葸克来 王健[1] 远光辉 杨田 

机构地区：[1]中国石油大学地球科学学院,山东青岛266555

出　　处：《现代地质》2011年第6期1152-1158,共7页Geoscience

基　　金：国家自然科学基金项目(40972080);国家科技重大专项项目(2011ZX05009-003);教育部新世纪优秀人才支持计划项目(NCET-06-0604)

摘　　要：为了模拟沉积地层埋藏成岩过程中,压实作用下储层物性参数的连续变化特征,采用自行设计的成岩作用模拟实验系统,利用不同的现代沉积物样品,开展了砂岩机械压实作用模拟实验。实验表明:砂岩机械压实作用过程中孔隙度和渗透率随深度的变化具有分段性,即早期速变阶段和晚期缓变阶段。利用缓变阶段的数据分析发现,深度与孔隙度之间存在着良好的指数关系,深度与渗透率之间存在着良好的乘幂关系,孔隙度与渗透率之间存在着良好的指数关系。只经历机械压实作用的情况下,相同物源、相同分选的砂岩,颗粒粒度越粗,压实作用过程中,压实减孔率越小,最终保存的孔隙越多,砂岩渗透性越好;不同分选、相近粒度的砂岩,分选越差,压实作用过程中,压实减孔率越大,最终保存的孔隙越少,砂岩渗透性越差。不同岩相类型的砂岩,在压实缓变阶段,分选好中砂岩相平均百米减孔量最小,其次为分选好细砂岩相和分选好粉砂岩相,再次为分选中等粗砂岩相,分选差含砂砾岩相平均百米减孔量最大。In order to simulate the physical property change of sedimentary strata in the diagenetic process,a set of new equipment was designed and applied to simulate the mechanical compaction using different modern sediments.Results of the experiments show that the porosity and permeability are not regularly changing during compaction,and it can be divided into two sections,i.e.a sudden change section at early stage and a uniform change section at later stage.In the uniform change section,the porosity decreases with the increase of the depth,and they have an exponential relationship;the permeability also decreases with the increase of the depth,and they have an exponentiational relationship;the porosity and permeability also have an exponential relationship.When the sandstone only experiences mechanical compaction,for the sediments with same source and separation,the more coarse of grain size is,the slower of compaction rate is,and the porosity and permeability will be larger;for the sediments with the similar source and grain size,the poorer sorting is,the quicker compaction rate is,and the porosity and permeability will be less.During the uniform change section,the porosity reduction per 100 meters is also different for different lithofacies in sandstones.The porosity reduction per 100 meters is the least in well sorted medium sandstone,followed by that in well sorted fine sandstone and well sorted siltstone,then that in medium sorted coarse sand,and that in poorly sorted pebbly sandstone is the largest.

关 键 词：孔隙度 渗透率 机械压实 成岩模拟 

分 类 号：TE122.2[石油与天然气工程—油气勘探]