鄂尔多斯盆地靖边气田古地貌恢复与储层特征分析  

Palaeogeomorphological restoration and analysis of reservoir characteristics in Jingbian gas field of Ordos basin

作　　者：苏海 段淑远 高棒棒 杜中东 李宏伟 李爱荣 SU Hai;DUAN Shu-yuan;GAO Bang-bang;DU Zhong-dong;LI Hong-wei;LI Ai-rong(School of Earth Science And Engineering,Xi'an Shiyou University,Xi'an 710065,China;Key Laboratory of Hydrocarbon Accumulation of Shannxi Province,Xi'an 710065,China;Changqing Geophysical Department,BGP Inc.,CNPC,Xi’an 710021,China;Changqing Branch of Geophysical Research Institute,BGP Inc.,CNPC,Xi’an 710021,China)

机构地区：[1]西安石油大学地球科学与工程学院,西安710065 [2]陕西省油气成藏地质学重点实验室,西安710065 [3]东方地球物理勘探有限责任公司研究院长庆物探处,西安710021 [4]中国石油集团东方地球物理公司研究院长庆分院,西安710021

出　　处：《地球物理学进展》2020年第3期1031-1037,共7页Progress in Geophysics

基　　金：国家自然科学基金项目(41772140);西安石油大学研究生创新与实践能力培养项目(YCS18112017)联合资助.

摘　　要：古地貌的分布特征是天然气富集程度的主要影响因素,因此古地貌恢复对于油气资源勘探开发至关重要.本文通过对研究区古生界的地质资料分析后发现,该地区钻井资料较少,依托钻井资料恢复古地貌的方法难以实现对古地貌的精细刻画.针对这一难题,提出了结合地震资料采用残余厚度法和层拉平技术,进行靖边气田东侧奥陶系马家沟组马五段古地貌恢复.为了准确划分地貌单元,通过联井正演模型和实际资料的对比的基础上,进行古地貌单元划分,识别出岩溶高地、残丘、洼地等古地貌单元以及在研究区内分布特征,最后得到了靖边气田东侧岩溶古地貌呈现出西高东低、北高南低、厚度不均一的分布规律.通过分析古地貌单元对储层分布的影响,经钻井试气验证,发现岩溶残丘和岩溶斜坡为天然气成藏极佳的古地貌单元,为靖边气田东侧地区的储层预测和井位优选提供了可靠的依据.The distribution characteristics of palaeogeomorphology are the mainly influencing factors of natural gas enrichment,so palaeogeomorphological restoration is of crucial importance to the exploration of oil and gas resources.By analyzing the existing geological data of Palaeozoic in the study area,it is found that the area is short of drilling data.And it is difficult to acquire a detailed description of palaeogeomorphology by methods based on drilling datas.To deal with this problem,residual thickness method and bedding flatting technology combined with seismic data were adopted to restore the Ordovician palaeogeomorphology of the third member of Majiagou Formation in the eastern part of Jingbian Gas Field.In order to accurately identify geomorphic unit,based on comparing the forward model of combined wells with the actual data,geomorphic unit can be divided,then,the palaeogeomorphological units such as karst highlands,residual hills and depressions and the distribution pattern in the study area can be identified.Finally,it can be concluded that the distribution characteristics of the karst palaeogeomorphology in Jingbian Gas Field are high in the west and north and low in the east and south.In addition,thickness appears uneven distributed.Also,by analyzing the influence of each palaeogeomorphological unit on reservoir distribution and drilling,it is found that the karst residual hills and karst slopes are the excellent palaeogeomorphological units for natural gas reservoir formation,which can provide a reliable basis for reservoir prediction and optimizing well location for eastern area of Jingbian Gas Field.

关 键 词：残余厚度法 层拉平技术 古地貌恢复 古地貌单元划分 

分 类 号：P631[天文地球—地质矿产勘探]