四川盆地中侏罗统页岩储层特征及其影响因素  

The reservoirs characteristics and its influencing factors of Middle Jurassic shale in Sichuan Basin

作　　者：刘苗苗[1] 付小平 谢佳彤 LIU Miaomiao;FU Xiaoping;XIE Jiatong(Exploration Company,SINOPEC,Chengdu 610041,China)

机构地区：[1]中国石化勘探分公司,四川成都610041

出　　处：《断块油气田》2023年第6期905-913,共9页Fault-Block Oil & Gas Field

基　　金：中国石油化工股份有限公司科技项目“涪陵地区侏罗系陆相页岩油气勘探评价技术”(P19022-5)、“四川盆地陆相页岩油气甜点地震预测技术研究”(P22159)。

摘　　要：四川盆地中侏罗统是陆相页岩油气主力勘探层系,具有较好的勘探前景。文中利用扫描电镜、N2吸附等分析测试手段,对元坝、复兴地区凉高山组页岩储层特征和孔隙结构进行了精细研究。研究表明:1)凉高山组页岩储层平均孔隙度介于3.21%~4.04%,渗透率介于0.0362×10^(-3)~0.0385×10^(-3)μm^(2),为低孔特低渗储层;2)研究区陆相页岩孔隙类型以黏土矿物孔、粒间孔等无机孔为主,其次为有机孔、微裂缝;孔径以介孔为主,其次为宏孔;3)研究区纹层状黏土质页岩相具有较大的比表面积和孔体积,孔隙形态以近似墨水瓶形、近似平行板状狭缝形为主,有利于页岩油气流动;4)岩相、有机质类型、成岩作用、构造作用等因素影响了研究区页岩储层的储集能力,岩相控制了孔隙度及孔隙类型,有机质类型控制了有机孔发育程度,成岩作用中有机质排烃、酸溶蚀增孔、黏土矿物转化扩径为储集空间改善提供了关键条件,构造作用造成区域上的孔隙差异。Middle Jurassic in Sichuan Basin is the main exploration series of continental shale oil and gas with great prospective.The characteristics and pore structure of the shale reservoirs in the Lianggaoshan Formation of Yuanba and Fuxing areas have been studied by means of scanning electron microscopy,N2 isothermal adsorption and other analytical methods.The results show that:(1)the shale reservoirs in Lianggaoshan Formation is a low porosity and ultra-low permeability reservoir with porosity ranging from 3.21%to 4.04%and permeability ranging from 0.0362×10^(-3) to 0.0385×10^(-3)μm^(2).(2)The pore types of continental shale in the study area are mainly inorganic pores such as clay mineral pores and intergranular pores,followed by organic pores and microfracture.The pore size is mainly mesoporous,followed by macropores.(3)The lamellar clay shale reservoirs in the study area has the major specific surface area and pore volume,and the pore shape is mainly ink bottle type and parallel plate shape slit type,which is beneficial to oil and gas flow in the shale.(4)The capacity of shale reservoirs is mainly controlled by lithofacies,organic matter types,diagenesis and tectonics.The lithofacies controlled porosity and pore type,organic matter types controlled development degree of organic pores.In the diagenetic evolution,hydrocarbon expulsion of organic matter,dissolution of organic acid to increase porosity and transformation of clay minerals to expand diameter provide key condition for the improvement of reservoir space.Tectonics causes regional pore difference.

关 键 词：孔隙特征 影响因素 中侏罗统 元坝地区 复兴地区 

分 类 号：TE122[石油与天然气工程—油气勘探]