济阳坳陷平方王油田碳酸盐岩潜山内幕储层特征及其主控因素

Characteristics and main controlling factors of layered reservoir in buried hill of carbonate rock in Pingfangwang Oilfield,Jiyang Depression

有利储层预测是制约目前下古生界碳酸盐岩潜山勘探由山头向内幕开展的重要因素之一,以济阳坳陷平方王油田下古生界潜山为研究对象,利用元素地球化学、矿物学、岩心常规分析等多种技术方法,分析内幕储层储集空间成因类型,明确储层发育主控因素,最终建立储层发育改造模式。结果表明:下古生界发育大套不同类型的碳酸盐岩是内幕储层形成的物质基础,内幕储层发育原生孔隙、构造裂缝、溶蚀孔洞-裂缝3种类型的储集空间,3种储集空间类型决定了储层受控于岩石类型、构造改造、流体改造3种地质因素;岩石类型是基础性因素,不仅决定了原生孔隙的量,且进一步影响岩石抗溶蚀与构造裂缝发育程度;构造改造是关键性因素,构造裂缝与溶蚀孔洞-裂缝的发育呈明显的正相关性;流体改造是决定性因素,深部热液和有机酸联合溶蚀形成了大量孔洞、微孔、微裂缝,大大改善了储层物性。

Favorable reservoir prediction is one of the important factors that control the current exploration from hilltop to inner reservoir in the buried hill of the ower Paleozoic carbonate. Taking the Lower Paleozoic buried hill in Pingfangwang Oilfield of Jiyang Depression as the study area,we combined element geochemistry,mineralogy,and core routine analysis to carry out a series of study. We analyzed the genetic type of the inner reservoir space,defined the master control factors of the reservoir,and established the reservoir development model. The results show that different types of carbonate developed in the Lower Paleozoic formed the basis of the inner reservoir. The inner reservoir has three different reservoir spaces including solution pore space-cracks,tectonic fractures,and primary pores,which suggests that the formation of the reservoir is controlled by rock type,tectonization and fluidization. Rock type is the basic factor controlling the number of primary pores,which further affects the solution-resistance of associated rocks and the development of tectonic fractures. Tectonization degree is a key factor. Tectonic fractures have a positive correlation with solution pore space-cracks. Fluidization degree is the crucial factor.A large number of pore spaces,micropores and microcracks can form through corrosion of deep hypothermal solution and organic acid,which greatly improves the reservoir property.