摘要
页岩油储层因微—纳米孔喉体系发育,使得油的赋存分散复杂,状态多样,研究困难。通过场发射扫描电镜、核磁共振、激光共聚焦和纳米CT等技术手段,对准噶尔盆地吉木萨尔凹陷中二叠统芦草沟组页岩油进行了研究。芦草沟组页岩油“甜点”粉—细砂岩和云质粉砂岩孔隙面孔率分布在11.0%~23.5%之间,大于2μm的粒间溶孔、粒内溶孔占比在49.0%以上。受烃源岩生烃超压运移、孔隙表面吸附和页岩油连续成藏不同阶段油质差异等复杂因素控制,油和孔隙水的分布在微—纳米尺度上具有较强的分异性:“甜点”储层中2~5μm以上孔隙内中质组分油和游离水赋存于孔隙中心,重质组分油以薄膜状赋存于孔隙表面;2μm以下孔隙中主要为充填状重质组分油。中质组分油动用性较好,而重质组分油则是未来提高采收率比较现实可行的目标。
The development of micro-nano pores and throats in shale oil reservoirs has made it complicated and diversified for the occurrence and state of oil,and is difficult to be studied.A case study was carried out with the Middle Permian Lucaogou Formation in the Jimsar Sag of Junggar Basin by the approaches of Field Emission Scanning Electron Microscopy(FESEM),Nuclear Magnetic Resonance(NMR),Laser Scanning Confocal Microscope(LSCM)and nano-CT.The plane porosities of siltstones and dolomitic siltstones in sweet spots of the study area range from 11.0%to 23.5%,and the dissolved pores and intragranular dissolved pores larger than 2μm account for more than 49.0%.The distribution of oil and pore water has strong differentiation in micro-nano scale,which is controlled by complex factors such as overpressure migration of hydrocarbon generation,pore surface adsorption and oil quality difference in different stages of continuous shale oil accumulation.In sweet spot reservoirs,intermediate oil and free water occur in the center of pores larger than 2μm,while heavy oil exists on pore surface as thin film.Pores with the size smaller than 2μm are mainly filled with heavy oil.Intermediate oil is relatively easier to be explored,while heavy oil is a more realistic and feasible target for enhanced oil recovery in the future.
作者
刘金
王剑
张宝真
曹剑
尚玲
张晓刚
王桂君
LIU Jin;WANG Jian;ZHANG Baozhen;CAO Jian;SHANG Ling;ZHANG Xiaogang;WANG Guijun(Laboratory of Xinjiang Shale Oil Exploration and Development,Karamay,Xinjiang 834000,China;Research Institute of Experiment and Detection,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China;Fengcheng Oilfield Area,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China;School of Sciences and Engineering,Nanjing University,Nanjing,Jiangsu 210023,China)
出处
《石油实验地质》
CAS
CSCD
北大核心
2022年第2期270-278,共9页
Petroleum Geology & Experiment
基金
中国石油科技重大专项“页岩油甜点形成机理与分类评价”(2019E-2602)资助。
作者简介
刘金(1989—),男,硕士,工程师,从事非常规油气地质及微束、微区分析研究。E-mail:602393581@qq.com。
