川南深层页岩有机质石墨化对储层孔隙的控制作用  

Controlling effect of organic matter graphitization on reservoir pore structure in deep shale reservoirs,southern Sichuan

作　　者：薛子鑫 姜振学[1,2] 郝绵柱 唐相路[1,2] 李生杰[1,3] 聂舟[4] 钟光海 吴伟 梁志凯 陈瑞华 郭婕 XUE Zixin;JIANG Zhenxue;HAO Mianzhu;TANG Xianglu;LI Shengjie;NIE Zhou;ZHONG Guanghai;WU Wei;LIANG Zhikai;CHEN Ruihua;GUO Jie(State Key Laboratory of Petroleum Resources and Prospecting,Beijing 102249,China;The Unconventional Oil and Gas Institute,China University of Petroleum,Beijing 102249,China;School of Geophysics,China University of Petroleum,Beijing 102249,China;Sichuan Changning Natural Gas Development Co.Ltd.,Chengdu 610000,China;Shale Gas Research Institute of Southwest Oil&Gas Field,PetroChina,Chengdu 610000,China)

机构地区：[1]油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)非常规油气科学技术研究院,北京102249 [3]中国石油大学(北京)地球物理学院,北京102249 [4]四川长宁天然气开发有限责任公司,四川成都610000 [5]中国石油西南油气田页岩气研究院,四川成都610000

出　　处：《中南大学学报（自然科学版）》2022年第9期3532-3544,共13页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(42072151,41872135)。

摘　　要：为研究深层页岩有机质石墨化特征及其对储层孔隙的控制作用,选择川南不同地区的深层龙马溪组页岩样品,首先,开展有机质分离、激光拉曼以及X射线光电子能谱实验,确定深层龙马溪组页岩的拉曼等效成熟度及有机质石墨化程度;其次,分别开展页岩及其对应有机质的二氧化碳吸附及氮气吸附实验,表征储层特征;最后,对比有机质石墨化对于储层孔隙的影响。研究结果表明:长宁西深层页岩拉曼等效成熟度均高于3.6%,石墨化程度均达到20%以上,而泸州地区深层页岩拉曼成熟度均低于3.2%,石墨化程度均低于13%,长宁西深层页岩拉曼等效成熟度及石墨化程度均比泸州深层页岩的高;不同深层样品间石墨化程度与成熟度存在良好的正相关关系;在深层页岩中,有机质为深层页岩提供了超过70%的孔体积和超过50%的比表面积。随着石墨化程度增高,有机质塑性增强,孔隙壁面复杂程度降低,孔体积和比表面积均降低,孔体积在孔径为2~30 nm的中孔段和大于50 nm的宏孔段降低更加明显,比表面积的降低则主要体现在孔径小于3 nm的孔隙中。In order to study the graphitization characteristics of organic matter in deep shale and its controlling effect on reservoir pores,the deep Longmaxi Formation shale samples from different areas in southern Sichuan were selected.Firstly,organic matter separation,laser Raman and X−ray photoelectron spectroscopy experiments were carried out to determine the Raman equivalent maturity and graphitization degree of organic matter in the deep Longmaxi shale.Secondly,carbon dioxide adsorption and nitrogen adsorption experiments of shale and its corresponding organic matter were carried out to show the characteristics of reservoir.Finally,the effect of graphitization of organic matter on reservoir porosity was compared.The results show that the Raman equivalent maturity of the deep shale in Changningxi is higher than 3.6%,and the graphitization degree is more than 20%.However,the Raman maturity in the Luzhou area is lower than 3.2%,and the graphitization degree in the Luzhou area is lower than 13%.Raman equivalent maturity and graphitization degree of Changningxi deep shale are higher than those of Luzhou deep shale.There is a good positive correlation between graphitization degree and maturity in different deep samples.In deep shale,organic matter also provides more than 70%of the pore volume and more than 50%of the specific surface area for the deep shale.With the increase of graphitization degree,the plasticity of organic matter increases,the complexity of the pore wall decreases and the pore volume and specific surface area decrease as well.The decrease in the pore volume is more obvious in the mesoporous segment of 2−30 nm and the macroporous segment of more than 50 nm.The decrease of the specific surface area mainly occurs in the pores with a pore size less than 3 nm.

关 键 词：深层页岩储层 有机质石墨化 孔隙结构 有机质孔 

分 类 号：TE122[石油与天然气工程—油气勘探]