玛湖凹陷风城组页岩油富集机制与甜点段优选  

Shale Oil Enrichment Mechanism and Sweet Spot Selection of Fengcheng Formation in Mahu Sag,Junggar Basin

作　　者：金之钧 梁新平[1] 王小军 朱如凯[1,5] 张元元[2] 刘国平[1,2] 高嘉洪[1,2] JIN Zhijun;LIANG Xinping;WANG Xiaojun;ZHU Rukai;ZHANG Yuanyuan;LIU Guoping;GAO Jiahong(Peking University,a.Institute of Energy,Beijing 100871,China;School of Earth and Space Sciences,Beijing 100871,China;Petroleum Exploration and Production Research Institute,Sinopec,Beijing 100083,China;PetroChina Daqing Oilfield Company Limited,Daqing,Heilongjiang 163000,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China)

机构地区：[1]北京大学能源研究院 [2]北京大学地球与空间科学学院,北京100871 [3]中国石化石油勘探开发研究院,北京100083 [4]中国石油大庆油田有限责任公司,黑龙江大庆163000 [5]中国石油勘探开发研究院,北京100083

出　　处：《新疆石油地质》2022年第6期631-639,共9页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(42090025)。

摘　　要：准噶尔盆地玛湖凹陷风城组为碱湖沉积,自下而上划分为风一段、风二段和风三段,岩性纵向上变化快,矿物成分复杂,富有机质,发育源储一体页岩油藏。油藏整体含油,但甜点分散,单层试油效果不理想,提产潜力不明确。根据岩心薄片及地球化学分析,玛湖凹陷风城组以纹层状粉砂质泥页岩夹白云岩为主,矿物组成以陆源碎屑矿物及碳酸盐矿物为主,随埋深孔隙体积变化和孔表面积变化一致,孔隙体积主要由宏孔(孔隙直径大于50 nm)贡献;烃源岩有机质类型以Ⅱ型为主,镜质体反射率为0.85%~1.40%,处于生油高峰期;风二段发育中—高角度剪切裂缝,风三段发育中—高角度剪切裂缝和低角度构造裂缝,其形成与发育程度受岩性、矿物组分、岩石力学性质等的控制。综合岩性组合及储集层物性、含油性等特征,划分出4个相对集中的甜点段。应在直井多段试油试采的同时,选择含油性好、裂缝较发育的甜点段,开展地质基础研究与地质工程一体化技术攻关,实施水平井提产试验,以实现研究区风城组页岩油勘探开发的全面突破。The Fengcheng formation in the Mahu sag is an alkaline lake sediment,and is divided into Feng 1 member,Feng 2 member and Feng 3 member from bottom to top.In the Fengcheng formation,the lithology vertically changes rapidly,the mineral composition is complex,and the organicrich shale source is integrated with the shale reservoir.The formation bears oil universally,but the sweet spots are scattered.The results of formation testing for single layers are not satisfied,showing an unclear production potential.According to core slices and geochemical analyses,the Fengcheng formation in the Mahu sag is dominated by lamellar silty shale intercalated with dolomite,which are mainly composed of terrigenous clastic minerals and carbonate minerals.With the variation of burial depth,the pore volume changes consistently with the variation of surface area of pores,and the pore volume is mainly contributed by macropores(pore diameter>50 nm).The source rock is dominated by Type Ⅱ organic matter,and the vitrinite reflectance ranges from 0.85%to 1.40%,indicating a peak oil generation period.There are many shear fractures with middle to high angles in the Feng 2 member,and shear fractures with middle to high angles and structural fractures with low angles in the Feng 3 member,whose formation and development degree are controlled by lithology,mineral composition,rock mechanical properties,etc.Based on the characteristics of lithologic assemblage,reservoir property and oilbearing property,four relatively concentrated sweet spots have been identified.When performing multiinterval formation testing and production testing in vertical wells,it is necessary to select sweet spots with good oil content and more fractures to conduct geological research and geologyengineering integration technology research,and to perform production improvement tests in horizontal wells,so as to realize comprehensive breakthrough for shale oil exploration and development in the Fengcheng formation in the study area.

关 键 词：玛湖凹陷 风城组 碱湖烃源岩 含油性 储集性 可动性 可压性 有利层段 

分 类 号：TE122.23[石油与天然气工程—油气勘探]