差异保存条件下页岩孔隙结构特征演化及其意义  

Evolution and implications of shale pore structure characteristics under different preservation conditions

作　　者：刘树根[1,2] 叶玥豪 冉波[1] 姜磊[3] 李智武 李金玺[1] 宋金民[1] 焦堃[1] 李泽奇[1] 李煜伟 LIU Shugen;YE Yuehao;RAN Bo;JIANG Lei;LI Zhiwu;LI Jinxi;SONG Jinmin;JIAO Kun;LI Zeqi;LI Yuwei(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,CDUT,Chengdu,Sichuan 610059,China;Xihua University,Chengdu,Sichuan 610039,China;Guangdong University of Petrochemical Technology,Maoming,Guangdong 525000,China;Sinohydro Bureau 7CO.,LTD,Chengdu,Sichuan 611730,China)

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059 [2]西华大学,四川成都610039 [3]广东石油化工学院,广东茂名525000 [4]中国水利水电第七工程局有限公司,四川成都611730

出　　处：《油气藏评价与开发》2020年第5期1-11,F0002,共12页Petroleum Reservoir Evaluation and Development

基　　金：四川省科技厅应用基础研究项目“四川盆地深层海相页岩储层特征”(2018JY0437)。

摘　　要：鉴于保存条件和页岩孔隙演化对页岩气勘探开发的重要性,对页岩气保存条件和页岩孔隙结构演化之间关系的研究有着重要的科学意义和学术价值。通过氩离子抛光、扫描电镜和氮气吸附等方法对具有差异保存条件的黑色页岩开展孔隙结构特征和演化研究,发现不同保存条件下黑色页岩孔隙结构存在较大差异。这种差异是在后期抬升过程中保存条件的差异所致,具体表现在:①保存条件好和保存条件差的黑色页岩无机孔均发育较少,原始粒间孔绝大多数被生成的烃类充填,两者之间无机孔隙特征基本相似;②两者有机质孔差异较大,保存条件较好的黑色页岩有机质孔孔径大,形状多成圆状或气泡状。保存条件遭到破坏的黑色页岩有机质孔孔径相对较小或不发育、形状多样,多成扁平状、多边形状,具有一定压扁变形的特征;③保存条件好的黑色页岩孔隙体积和比表面积优于保存条件遭到破坏的黑色页岩;④黑色页岩的孔隙演化受保存条件的影响,孔隙在演化过程中,页岩的岩相和成岩作用控制黑色岩原始孔隙形态和分布,也决定有机质(油)分布形态,有机质热演化(原油裂解)影响了有机质孔的存在,而后期抬升改造过程中保存条件的好坏影响了孔隙结构(形态、大小、孔隙体积分布),因此有机质孔的孔径大小、形状和孔隙度在一定程度反映了富有机质页岩保存条件的优劣。Because of the importance of preservation conditions and shale pore evolution to shale gas exploration and development,it is of great scientific significance and academic value to study the relation between them.The pore structure characteristics and evolution of black shale with different preservation conditions have been studied by means such as argon ion polishing,scanning electron microscope and nitrogen adsorption,and it is found that the pore structure of black shale under different preservation conditions are significantly different.This difference is caused by the difference of preservation conditions in the late uplift process,which is manifested in the following aspects.First,inorganic pores in black shale with good or bad preservation conditions are both less developed,and most of the original intergranular pores are filled with generated hydrocarbons.The inorganic pore characteristics between them are basically similar.Second,the organic pores in black shale are of great difference under different preservation conditions.The diameter of shale organic pores is larger in good preservation conditions,which are in round or bubble shape.While the organic pores are relatively smaller in diameter or totally absent in poor preservation condition,which are in flat or irregular shape with the certain characteristics of flattening and deformation.Third,the pore volume and specific surface area of the black shale under good preservation conditions are better than that under poor conditions.Fourth,the porosity evolution of black shale is affected by preservation conditions.The original pore morphology and distribution are controlled by facies and diagenesis process,and so are the organic matter(oil)distribution form.Thermal evolution of organic matter(oil cracking)influences the existence of organic pores.Whereas,in the late uplifting process,the pore structures(shape,size,pore volume)are affected by the quality of the preservation condition.Therefore,the size,morphology and porosity of the shale organic pores ref

关 键 词：龙马溪组 页岩气 保存条件 孔隙结构 孔隙演化 

分 类 号：TE311[石油与天然气工程—油气田开发工程]