鄂尔多斯盆地东北部奥陶系马四段白云岩储层特征及主控因素  

Characteristics and main controlling factors of dolomite reservoir in the fourth member of the Ordovician Majiagou Formation in the northeast of Ordos Basin

作　　者：苏文杰 鲁慧丽[4] 乔德民 李辉 石磊[3] 罗开通[6] SU Wenjie;LU Huili;QIAO Demin;LI Hui;SHI Lei;LUO Kaitong(Xi’an Shiyou University,Xi’an,Shaanxi 710018,China;Key Laboratory of Oil and Gas Reservoir Geology in Shaanxi Province;Exploration Division of Changqing Oilfield Company of China National Petroleum Corporation;PetroChina Hangzhou Research Institute of Geology,Hangzhou,Zhejiang 310023,China;Second Logging Branch of Bohai Drilling Engineering Co.,Ltd,CNPC;Chongqing University of Science and Technology)

机构地区：[1]西安石油大学,陕西省西安市710018 [2]陕西省油气成藏地质学重点实验室 [3]中国石油长庆油田公司勘探事业部 [4]中国石油杭州地质研究院,浙江省杭州市310023 [5]中国石油集团渤海钻探工程有限公司第二录井分公司 [6]重庆科技大学

出　　处：《海相油气地质》2024年第2期125-135,共11页Marine Origin Petroleum Geology

基　　金：中国石油天然气集团有限公司攻关性应用性科技专项“碳酸盐岩油气富集规律及有利区带研究”(2023ZZ16YJ01);长庆油田公司重大科技专项“鄂尔多斯盆地中元古界—奥陶系构造沉积演化、成源机制与勘探新领域研究”(ZDZX2021)联合资助。

摘　　要：米探1井等多口探井在鄂尔多斯盆地东北部奥陶系马四段白云岩中获得高产天然气流,展示出该区域马四段具有良好的勘探前景。然而对盆地东北部马四段是否发育规模白云岩储层还存在争议,白云岩储层分布不清制约了下一步勘探部署。基于岩心、薄片、场发射扫描电镜及地球化学特征等资料,对盆地东北部奥陶系马四段白云岩储层特征及其发育控制因素开展了系统研究,并预测了盆地东北部奥陶系马四段白云岩储层分布。研究结果表明:(1)盆地东北部奥陶系马四段白云岩发育潮坪型白云岩储层、丘滩型白云岩储层和生物扰动型白云岩储层,3类白云岩储层储集空间主要为晶间孔,含少量微裂缝,平均孔隙度分别为4.77%、5.12%和2.52%。(2)白云岩储层的形成与丘滩体、生物扰动作用和白云石化作用相关。白云石化作用是潮坪型白云岩储层晶间孔形成的关键,丘滩体和白云石化作用控制了丘滩型白云岩储层发育,生物扰动作用和白云石化作用控制了生物扰动型白云岩储层发育。(3)盆地东北部神木—靖边地区在奥陶纪马四期位于低隆起带上,有利于丘滩体发育和生物扰动作用、白云石化作用的发生,形成的白云岩储层可为天然气富集提供规模储集空间。Multiple exploration wells including well Mitan 1 have obtained high production natural gas flow in the dolomite of the fourth member of the Ordovician Majiagou Formation(O1m4)in the northeast of Ordos Basin,demonstrating that the O1m4 of the region has good exploration prospects.However,there is still controversy over whether large-scale dolomite reservoirs are developed in the O1m4 in the northeastern basin,and the unclear distribution of dolomite reservoirs restricts the next exploration deployment.Based on comprehensive data such as core,thin sections,field emission scanning electron microscopy and geochemical characteristics,a systematic study is conducted on the characteristics and development controlling factors of the O1m4 dolomite reservoir in the northeast of Ordos Basin.On this basis,the distribution of the O1m4 dolomite reservoir in the northeast of the basin is predicted.The research results indicate that:(1)Tidal flat type dolomite reservoir,mound-shoal type dolomite reservoir and bioturbation type dolomite reservoir are developed in the O1m4 in the northeast of Ordos Basin.The storage space of the three types of dolomite reservoir is mainly intergranular pores with a small number of micro cracks,and the average porosity is 4.77%,5.12%and 2.52%respectively.(2)The formation of dolomite reservoirs is related to mound-shoal complex,bioturbation and dolomitization.The development of tidal flat type dolomite reservoir is related to dolomitization,which is the key to the formation of intergranular pores in such reservoirs.The development of the mound-shoal type dolomite reservoir is controlled by the mound-shoal complex and dolomitization.The mound-shoal complex is the material basis for reservoir development,and the dolomitization further enhances the compressive capacity of the reservoir,which is conducive to the preservation of intergranular pores.Bioturbation and dolomitization control the development of bioturbation type dolomite reservoir.The burrows formed by bioturbation lay the foundation for res

关 键 词：白云石化作用 生物扰动作用 丘滩体 白云岩储层 马四段 鄂尔多斯盆地东北部 

分 类 号：TE122.1[石油与天然气工程—油气勘探]