鄂尔多斯盆地延长东区块本溪组砂砾岩储层孔隙及可动流体差异赋存特征  

Differential Occurrence Characteristics of Pores and Movable Fluids in the Tight Glutenite Reservoir in Yanchang East Block of Ordos Basin

作　　者：吕敏 刘江斌 王茜 吴小斌[2] 余皓天 崔宏俊 魏灿灿 L Min;LIU Jiangbin;WANG Qian;WU Xiaobin;YU Haotian;CUI Hongjun;WEI Cancan(The First Natural Gas Plant of Shaanxi Yanchang Oil and Gas Exploration Company,Yan an,Shaanxi 716000;School of Petroleum Engineering and Environmental Engineering,Yan an University,Yan an,Shaanxi 716000;TheSixth Gas Production Plant of PetroChina Changqing Oilfield Company,Xi an,Shaanxi 710016)

机构地区：[1]陕西延长石油油气勘探公司采气一厂,陕西延安716000 [2]延安大学石油工程与环境工程学院,陕西延安716000 [3]中国石油长庆油田分公司第六采气厂,陕西西安710016

出　　处：《地质与勘探》2023年第2期433-442,共10页Geology and Exploration

基　　金：陕西省自然科学基础研究计划项目(编号:2021JQ-627);延安大学博士科研启动项目(编号:YDBK2017-36)联合资助

摘　　要：以鄂尔多斯盆地延长东区块本溪组砂砾岩储层为研究对象,通过铸体薄片、扫描电镜、高压压汞和核磁共振等方法分析储层孔隙与流体差异赋存特征,探讨流体差异赋存影响因素。结果表明:储层主要发育粒间溶孔和晶间孔,进一步分为裂缝-粒间溶孔型、晶间孔-溶孔型、溶孔型、微孔型储层,以裂缝-粒间溶孔型、晶间孔-溶孔型储层发育较好。储层可动流体饱和度为51.16%~86.82%,T 2谱为双峰态,呈左低右高型。孔隙发育差异对可动流体流体赋存呈现出不同特征,孔隙发育较差的溶孔型和微孔型储层仍具有较高的可动流体饱和度。粒间溶孔、最大连通孔喉半径、中值半径及最大进汞饱和度等影响储层可动流体饱和度,以裂缝-粒间溶孔型、晶间孔-溶孔型储层尤为显著。溶孔型、微孔型储层可动流体饱和度受铁白云石影响更为明显,铁白云石能够改善界面的润湿性,使流体在其纳米孔隙中仍具备较好的流动能力。Taking the Benxi Formation glutenite reservoir in Yanchang east block of the Ordos Basin as an example,this work analyzed the occurrence characteristics of reservoir pores and fluids by means of casting thin section,scanning electron microscope,high pressure mercury injection and nuclear magnetic resonance(NMR),and further discussed the influencing factors of the differential occurrence of fluids.The reservoir mainly includes intergranular solution pores and intercrystalline pores,which can be subdivided into fracture-intergranular solution pores,intercrystalline pore-dissolved pores,dissolved pores and micro pores.Especially,fracture-intergranular dissolved pores and intergranular pore-dissolved pores possess good reservoir properties.The reservoir movable fluids have a saturation of 51.16%~86.82%,and the T 2 spectra are mainly bimodal,low on the left and high on the right.The differences of reservoir pore development exert different controls on the movable fluids,and dissolved pore and microporous reservoirs with poor pore development can still have high movable fluid saturation.Intergranular dissolved pore,maximum connected pore throat radius,median radius and maximum mercury saturation affect the reservoir movable fluid saturation,especially in fracture-intergranular dissolved pore and intergranular pore-dissolved pore reservoirs.The movable fluid saturation of solution porous and microporous reservoirs is more significantly affected by iron dolomite.Iron dolomite can improve the wettability of the interface,which results in good fluid ability in its nano-pores.

关 键 词：可动流体饱和度 微观孔隙结构 砂砾岩储层 本溪组 延长东区块 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]