莱阳凹陷水南组页岩气储层微观特征研究

Study on Microscopic Characteristics of Shale Gas Reservoirs in Shuinan Formation in Laiyang Depression

本文对莱阳凹陷水南组页岩气储层的微观特征进行了研究。采用剖面和钻井两种岩心样品的综合分析和实验方法,发现该储层页岩的孔隙度较低,发育多种储集空间类型,主要为残余的原生孔隙或微裂缝有机质生烃形成的微孔隙、黏土矿物转化形成的孔隙、长石和方解石等溶蚀形成的孔洞等。这些微孔隙及裂缝的存在,为页岩气的赋存提供了空间。通过压汞、低温液氮以及CO_(2)吸附3种实验综合测试表明剖面样品与钻井样品差异。水南组泥页岩孔径主要介于5~13 nm,平均为8.23 nm,泥页岩总孔比表面积平均为5.72 m^(2)/g,总孔容平均为0.008 cm^(3)/g,对页岩气储层的开发和生产具有重要的指导意义,为莱阳凹陷水南组页岩气田的有效开发提供科学依据。

In this paper,microscopic characteristics of shale gas reservoirs in Shuinan formation of Laiyang depression has been studied.By using comprehensive analysis and experimental methods of profile and drilling core samples,it is found that shale has low porosity.Multiple types of reservoir spaces are developed,including mainly consisting of residual primary pores or micro cracks formed by organic matter hydrocarbon generation,pores formed by clay mineral transformation,and pores formed by dissolution of feldspar and calcite.The existence of these micropores and cracks provides space for the occurrence of shale gas.The comprehensive testing of mercury intrusion,low temperature liquid nitrogen,and CO_(2) adsorption show differences between the profile sample and the drilling sample.The average pore size of the shale in Shuinan formation is mainly 5~13nm,and the average size is 8.23nm.The average total pore specific surface area of the shale is 5.72 m^(2)/g,and the average total pore volume is 0.008 cm^(3)/g.This has important guiding significance for the development and production of shale gas reservoirs.It will provide scientific basis for the effective development of Shuinan formation shale gas field in Laiyang depression.