大港油田孔南地区上石盒子组碎屑岩储层物性控制因素

Controlling factors of the clastic reservoirs in the Upper Shihezi Formation,southern Kongdian,Dagang Oil Field

通过对储层物性数据资料的分析和整理,研究了孔南地区上石盒子组碎屑岩储集层特征及其控制因素。结果表明:研究区上石盒子组碎屑岩储层为低孔低渗储层,渗透率与孔隙度呈正相关性。储层孔隙的连通性好,属于孔隙型储层。孔隙类型以次生粒间溶孔为特征。晚成岩期,岩屑、填隙物、长石颗粒以及高岭石发生溶蚀,产生了大量的次生孔隙,改善了储层物性。沉积条件、压实作用、胶结作用和溶蚀作用是控制储层性质的主要因素。

The clastic reservoirs in the Upper Shihezi Formation,southern Kongdian,Dagang Oil Field are expected to be the favourable area for the Palaeozoic petroleum exploration.The present paper deals with the lithology and physical properties of the clastic reservoirs and their controlling factors on the basis of cores and cast thin sections,SEM,X-ray diffractional patterns and vitrinite reflectance.The clastic reservoirs in the Upper Shihezi Formation are made up of low-porosity and low-permeability reservoirs.There a positive correlation between the porosity and permeability.The clastic reservoirs are well connected,and assigned to the porosity-type reservoirs.The porosity type is dominated by secondary intergranular solution openings.During the late diagenesis,the dissolution of lithoclastics,interstitial material,feldspar grains and kaolinite brought about abundant secondary pores,and resulted in the improvement of the porosity and permeability of the clastic reservoirs.The major controlling factors include sedimentary facies,compaction,cementation and dissolution.