摘要
探讨川西新场地区须家河组第二段致密砂岩优质储层形成的控制因素,为预测优质储层提供依据。根据岩心、岩石薄片、扫描电镜、压汞及测井资料分析,须二段储层以岩屑砂岩、长石岩屑砂岩为主,喉道属极细-细孔喉,孔隙度主要在2%~4%,渗透率主要在(0.02~0.04)×10-3μm 2,属超低孔、超低渗型致密砂岩储层。优质储层受沉积微相及成岩作用的控制,水下分流河道微相的物性最好。对水下分流河道进行岩相学研究发现,平行层理砂岩相的渗透率更高,是最有利的岩相类型。水岩反应引起的长石、易溶岩屑等颗粒的溶解形成了大量次生孔隙,是须二段优质储层形成的关键。斜长石对次生溶孔的贡献高于钾长石,火山岩碎屑溶蚀最有利于次生溶孔的形成;绿泥石主要保存了原生粒间孔隙;层理缝、层面缝和冲刷面缝改善了储层渗流能力,构造缝对单井产能贡献很大。
The controlling factors of formation of high quality tight sandstone reservoir in the second member of Xujiahe Formation(T 3 x 2)in Xinchang area of Western Sichuan are discussed in order to provide basis for predicting high quality reservoir.Drilling core and thin section observation,SEM,mercury intrusion and logging data analyses indicate that the types of reservoir sandstone are mainly lithic sandstone and feldspathic litharenite.It shows that the T 3 x 2 reservoir possesses extremely fine pore throat,with the porosity of 2%~4%and permeability of(0.02~0.04)×10-3μm 2,characteristic of ultra-low porosity and ultra-low permeability tight sandstone reservoirs.The high quality reservoirs are mainly controlled by sedimentary microfacies and diagenesis,in which dissolution greatly improves the physical properties of reservoirs.The underwater distributary channel microfacies has the best physical properties and the parallel layered sandstone facies has higher permeability and is the most favorable facies for the formation of hydrocarbon material.The dissolution of feldspar,rock debris and other particles caused by water-rock reaction has resulted in the formation of a large number of secondary pores,which is the key to the formation of T 3 x 2 high-quality reservoirs.The dissolution of plagioclase contributed more to secondary pores than K-feldspar,and volcanic debris was the most favorable debris to the formation of secondary pores.Meanwhile,the chlorite plays a role in the preservation of primary pores,and bedding fractures,bedding surface fractures and erosional basal surface fractures improve the seepage capacity of reservoirs.Structural fractures contribute greatly to the productivity of a single well.
作者
王志康
林良彪
余瑜
吴冬
刘磊
WANG Zhikang;LIN Liangbiao;YU Yu;WU Dong;LIU Lei(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China)
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第6期661-672,共12页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家科技重大专项(2016ZX05002-004-10)。
关键词
优质储层
须家河组
新场地区
川西拗陷
主控因素
high quality reservoir
Xujiahe Formation
Xinchang area
western Sichuan Depression
main controlling factors
