四温阶密闭热解录井技术在涠西南凹陷页岩油可动性评价中的应用  

Application of four-temperature-step sealed pyrolysis logging technology to shale oil mobility evaluation in the Weixinan sag

作　　者：陈沛 王瑞科 杜坤 曾烃详 刘宏坤 张书铭 CHEN Pei;WANG Ruike;DU Kun;ZENG Tingxiang;LIU Hongkun;ZHANG Shuming(CNOOC China Limited Zhanjiang Company,Zhanjiang,Guangdong 524057,China;China France Bohai Geoservices Co.,Ltd.(Zhanjiang),Zhanjiang,Guangdong 524033,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang),Zhanjiang,Guangdong 524000,China)

机构地区：[1]中海石油(中国)有限公司湛江分公司 [2]中法渤海地质服务有限公司湛江分公司 [3]南方海洋科学与工程广东省实验室(湛江)

出　　处：《录井工程》2024年第3期26-32,38,共8页Mud Logging Engineering

基　　金：中国海洋石油集团有限公司“十四五”重大科技项目“海上深层/超深层油气勘探技术”(编号:KJGG2022-0405)。

摘　　要：传统地化热解技术在分析过程中存在烃类轻组分易散失的问题,这导致地化热解参数S0参数失真。轻质烃类散失过程受多种因素影响,目前的热解校正恢复方法仍无法准确恢复样品实际的烃类含量,制约了传统地化热解技术对页岩油可动性的准确评价与应用。针对上述问题,提出应用四温阶密闭热解录井技术评价涠西南凹陷页岩油可动性的方法,将该方法获得的Sg与S01值之和定义为四温阶密闭热解的S0,是现场岩石热解S0的35.7倍,由此实现了全组分烃类的梯度分析。基于四温阶密闭热解和现场热解TOC得到的涠洲X构造WYX 1井取心段含油饱和度指数OSI平均为258 mg/g,气态烃指数平均为0.085,轻重比平均为0.35,指示研究区页岩油可动性好,具备开采潜力。四温阶密闭热解录井技术可有效避免轻质烃类散失,实现了气态烃和游离烃含量的精确测定,还原了页岩的真实含烃情况,为海上页岩油可动性评价提供了可靠的方法。Traditional geochemical pyrolysis technology has the problem of the easy loss of light components of hydrocarbons during the analysis process,resulting in the distortion of the geochemical pyrolysis parameter S0,and the loss process of light hydrocarbons is affected by various factors.The current pyrolysis correction and restoration methods still cannot accurately restore the actual hydrocarbon content of the sample,which have constrained the accurate evaluation and application of traditional geochemical pyrolysis technology to shale oil mobility.In response to the above problems,a method of applying the four-temperature-step sealed pyrolysis logging technology to evaluating the mobility of shale oil in the Weixinan sag is proposed.The sum of Sg and S01 values obtained by this method is defined as the S0 of the four-temperaturestep sealed pyrolysis,which is 35.7 times higher than the S0 of on-site rock pyrolysis,and the gradient analysis of the fullcomponent hydrocarbons is realized.Obtained from the four-temperature-step sealed pyrolysis and on-site pyrolysis TOC for the cored intervals of well WYX 1 of Weizhou X structure,the average oil saturation index(OSI)is 258 mg/g,the average gaseous hydrocarbon index is 0.085,and the average ratio of light hydrocarbon to heavy hydrocarbon ratio is 0.35,indicating that the shale oil in the study area has good mobility and potential for exploitation.The four-temperature-step sealed pyrolysis logging technology can effectively avoid the loss of light hydrocarbon,realize the accurate determination of gaseous hydrocarbon and free hydrocarbon content,reduce the real hydrocarbon content of shale,and provide a reliable method for evaluating the mobility of offshore shale oil.

关 键 词：涠西南凹陷 密闭热解 气态烃 游离烃 页岩油 岩石热解 

分 类 号：TE132.1[石油与天然气工程—油气勘探]