辉绿岩床侵入对围岩有机质热演化影响的模拟研究——以赵家山下马岭组剖面为例  

Numerical simulation of influence of diabase bed intrusion on thermal evolution of organic rich host rock:A case study of Zhaojiashan Xiamaling Formation

作　　者：刘君兰 张金川[2] 王胜 陈莉 牛嘉亮 LIU Junlan;ZHANG Jinchuan;WANG Sheng;CHEN Li;NIU Jialiang(Research Institute of Petroleum Exploration&Development,Beijing 100083,China;China University of Geosciences,Beijing 100083,China;No.9 Oil Production Plant,Changqing Oilfield Company of PetroChina,Yinchuan,Ningxia 750006,China;Administrative Committee of Chongqing Hi-Tech Industry Development Zone,Chongqing 401329,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国地质大学(北京),北京100083 [3]中国石油长庆油田第九采油厂,宁夏银川750006 [4]重庆高新技术产业开发区管理委员会建设局,重庆401329

出　　处：《油气藏评价与开发》2022年第1期255-264,共10页Petroleum Reservoir Evaluation and Development

基　　金：国家自然科学基金“页岩含气性关键参数测试及智能评价系统”(41927801)。

摘　　要：燕山地区中上元古界下马岭组发育大套黑色页岩,是页岩气勘探的潜在目标层位。野外剖面调查显示下马岭组地层中有多套辉绿岩床侵入,是制约油气成藏的关键因素。选取赵家山下马岭组剖面为研究对象,在实测剖面以及开展成熟度测定的基础上,重点对侵入黑色页岩段的一套约7 m厚的辉绿岩床对围岩成熟度的影响开展数值模拟研究。结果表明,这套辉绿岩床对围岩R;(镜质体反射率)的影响范围约为8.5 m,是自身厚度的1.2倍,并且靠近岩床方向R;呈指数增加。数值模拟结果显示,这套辉绿岩在110年后基本冷却,对围岩地温场的扰动范围约为100 m,远大于对R;的影响范围,只有当围岩温度能达到并超过250℃时才会引起R;值的变化响应。辉绿岩床厚度越大,对围岩R;的影响范围越大,靠近岩床方向R;增加的程度越大;辉绿岩床对围岩有机质R;的影响范围为自身厚度的1倍以上。The black shales is widely distributed in Proterozoic Xiamaling Formation of Yanshan area,making the Xiamaling Formation to be an important potential target for shale gas exploration.Field profile survey shows that several sets of diabase sill intruded into Xiamaling Formation,which has great influence on oil and gas accumulation.Therefore,the numerical simulation study on the influence of a set of diabase bed about 7 m thick on the maturity of host rock is carried out based on the measurement of the field section and bitumen reflectance of the neighbouring shales.The results show that the influence range of this diabase bed on R;of organic matter in host rock is about 8.5 m,which is about 1.2 times of its own thickness.The measured R;values increases exponentially near the bedrock.The numerical simulation results show that the diabase will cool down almost completely after 110 years,and the disturbance range to the surrounding rock geothermal field is about 100 m,which is much larger than the influence range of R;.Only when the surrounding rock temperature is greater than or equal to 250℃can it cause the change response of the R;values.The greater the thickness of diabase bed,the greater the influence range on R;of organic matter in host rock,and the greater the increase of R;near the bedrock.The influence range of diabase bed on R;of organic matter in host rock is about the same to its own thickness.

关 键 词：下马岭组 露头剖面 辉绿岩床 黑色页岩 有机质成熟度 

分 类 号：TE121[石油与天然气工程—油气勘探]