晚期快速埋藏过程中微裂缝对深层不同成岩强度碎屑岩储集层的改造作用——来自准噶尔盆地南缘白垩系清水河组成岩物理模拟的启示  

Reformation of deep clastic reservoirs with different diagenetic intensities by microfractures during late rapid deep burial:Implications from diagenetic physical simulation of Cretaceous Qingshuihe Formation in the southern margin of Junggar Basin,NW China

作　　者：靳军[1,2,3] 鲜本忠 连丽霞[1,2,3] 陈思芮[4,5] 王剑 李嘉奇 JIN Jun;XIAN Benzhong;LIAN Lixia;CHEN Sirui;WANG Jian;LI Jiaqi(Research Institute of Experiment and Detection,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China;CNPC Key Laboratory of Conglomerate Reservoir Exploration and Development,Karamay,Xinjiang 834000,China;Xinjiang Laboratory of Petroleum Reserves in Conglomerate,Karamay,Xinjiang 834000,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中国石油新疆油田公司实验检测研究院,新疆克拉玛依834000 [2]中国石油砾岩油气藏勘探开发重点实验室,新疆克拉玛依834000 [3]新疆砾岩油藏实验室,新疆克拉玛依834000 [4]中国石油大学(北京)地球科学学院,北京102249 [5]油气资源与探测国家重点实验室,北京102249

出　　处：《石油勘探与开发》2023年第2期309-321,共13页Petroleum Exploration and Development

基　　金：国家自然科学基金项目(41872113,42172109,42172108);国家重点研发计划项目(2018YFA0702405);中国石油天然气集团有限公司-中国石油大学(北京)战略合作科技专项(ZLZX2020-02);中国石油大学(北京)科研启动基金项目(2462020BJRC002,2462020YXZZ020)。

摘　　要：以准噶尔盆地南缘白垩系清水河组埋藏史为约束,利用露头区低成熟砂岩样品开展成岩物理模拟实验,并结合区域地质资料,探讨微裂缝对不同成岩强度储集层的改造作用及其对优质储集层发育的意义。研究结果表明:大尺度微裂缝主要形成于晚期快速埋深阶段,形成时间与有机酸充注基本发生在同一时期。微裂缝的发育为油气在深层、超深层碎屑岩中的运移创造了良好的条件,也为有机酸沿着微裂缝进入储集层促进胶结物与颗粒发生晚期持续性溶蚀提供了可能。快速埋深前储集层的基质孔隙、微裂缝的发育与否决定了快速埋深过程形成的微裂缝对储集层的改善程度。快速埋深前基质孔隙与微裂缝越发育、胶结程度越低,晚期快速埋深中的微裂缝越发育、溶蚀程度越高,储集层质量的改善程度越明显,实验中储集层渗透率最大增加55%。如果快速埋深前储集层胶结作用强烈、基质孔隙缺乏但已局部发育微裂缝,则晚期快速埋深中的微裂缝发育程度也相对较高,可使渗透率增加43%。但如果快速埋深前储集层的胶结作用强烈、基质孔隙缺乏,且不存在微裂缝,那么晚期快速埋深形成的微裂缝有限,渗透率仅增加16%。晚期快速埋深过程中大尺度微裂缝的形成及其对有机酸溶蚀的促进,是深层、超深层优质储集层发育的重要原因。Constrained by the geological burial history of Cretaceous Qingshuihe Formation in the southern margin of Junggar Basin,the diagenetic physical simulation experiment was carried out with the low-mature sandstone samples taken from the outcrop area.Then,coupling with the regional geological data,the reformation of reservoirs with different diagenetic intensities by microfractures and the significance of microfractures for development of high-quality reservoirs were discussed.The results show that the large-scale microfractures were formed in the stage of late rapid deep burial,roughly equivalent to the period when organic acids were filled.The microfractures created good conditions for migration of oil and gas in deep and ultra-deep clastic rocks,and also enabled the transport of organic acids to the reservoirs for ensuing the late continuous dissolution of cements and particles.The existence of matrix pores and microfractures in the reservoirs before the rapid deep burial determined how the microfractures formed during rapid deep burial improved the reservoir quality.If matrix pores and microfractures were more developed and the cementation degree was lower before the rapid deep burial,the microfractures would be more developed and the dissolution degree would be higher during the late rapid deep burial,and so the reservoir quality would be improved more greatly,which can increase the reservoir permeability by up to 55%.If cementation was very strong,but matrix pores were not developed and microfractures existed locally before the rapid deep burial,the microfractures would also be more developed during the late rapid deep burial,which can increase the reservoir permeability by 43%.If cementation was strong,matrix pores were absent,and microfractures were not developed,limited microfractures would be formed during the late rapid deep burial,which can increase the reservoir permeability by only 16%.Formation of large-scale microfractures during late rapid deep burial and promotion of such microfractures to the diss

关 键 词：快速埋深 微裂缝 物理模拟 深层储集层 白垩系清水河组 准噶尔盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]