致密砂岩储集空间全孔喉直径表征及其意义——以松辽盆地龙虎泡油田龙26外扩区为例  

Overall pore characterization of tight sandstone reservoir space and its significance:a case study of the outer expansion area of Long 26 in Longhupao oilfield,Songliao basin

作　　者：刘薇 卢双舫 王民 张世祥[2] 刘洋[1] 周能武 关莹 王海龙 Liu Wei;Lu Shuangfang;Wang Min;Zhang Shixiang;Liu Yang;Zhou Nengwu;Guan Ying;Wang Hailong(School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Exploration and Development Research Institute,Daqing Oilfield Company Limited,Daqing,Heilongjiang 163712,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《东北石油大学学报》2018年第6期41-51,103,123,124,共14页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(41672116);国家科技重大专项(2016ZX05046-001-005);教育部中央高校自主创新科研计划项目(17CX05012)

摘　　要：利用场发射扫描电镜、恒速压汞、高压压汞和低温氮气吸附等技术,对松辽盆地龙虎泡油田龙26外扩区青山口组二、三段致密砂岩储层储集空间类型,以及微观全孔喉直径分布进行定性及定量表征。结果表明:研究区致密储层物性较差,为低孔/超低孔—超低渗致密砂岩储层;储层的孔隙类型为残余粒间孔、长石和方解石溶蚀孔、晶间微孔和少量微裂缝,除压实作用外,方解石胶结和黏土矿物充填原生粒间孔是造成物性差的重要原因。厘定恒速压汞、高压压汞和低温氮气吸附三种实验联合表征的孔喉直径分布拼接点,用恒速压汞实验表征直径大于230nm的孔喉;用高压压汞实验表征直径介于20～230nm的孔喉;用低温氮气吸附实验表征直径小于20nm的孔喉;研究区致密砂岩储层孔喉直径为2～600nm,主要介于100～400nm,伴有极少量直径为200～600μm的孔隙,属于Ⅱ-Ⅲ类致密储层;小孔喉对致密储层渗透率的影响不大,但不能忽视对致密储层储集性的贡献。该研究结果为龙虎泡油田优质储层预测提供参考。The pore size distribution is a key parameter for reservoir grading evaluation and estimation of production capacity.The complexity of the pore-throat structure of tight sandstone reservoirs has made it impossible for any single experiment to accurately quantify its pore size distribution.Scanning electron microscopy(SEM),rate-controlled mercury(RCP),mercury intrusion porosimetry(MIP)and nitrogen gas adsorption(N2GA)were conducted synthetically on tight sandstones reservoir from the Ⅱ-Ⅲ sections of the Qingshankou formation of the upper Cretaceous in the Long 26 outer expansion area of the Longhupao oilfield in the Songliao basin to characterize the reservoir space types and microscopic overall pore size distribution qualitatively and quantitatively.The results show that the tight reservoirs in the study area have poor physical properties and are low-porosity/ultra-low porosity-ultra-low permeability tight sandstone reservoirs.The pore types are residual intergranular pores,feldspar and calcite dissolution pores,intercrystalline micropores and a small number of micro-cracks.In addition to compaction,calcite cementation and the filling of primary intergranular pores with clay minerals are important causes of poor physical properties.Splicing points for the pore size distribution jointly characterized by RCP,MIP and N2GA were accurately determined.It was determined that RCP was used to characterize pore throats larger than 230 nm in diameter,MIP was used to characterize pore throats with diameters between 20 nm and 230 nm,N2GA was used to characterize pore throats with diameters less than 20 nm.The pore throat diameter distribution of tight sandstone reservoirs in the study area ranges from 2 to 600 nm.The pore throat diameter distribution of tight sandstone reservoirs in the study area ranges from 2 to 600 nm.The main distribution range is from 100 nm to 400 nm,with a very small number of pores with a diameter of 200 to 600μm.It is a thght reservoir of classⅡ-Ⅲ.Small pore throat has little effect on the p

关 键 词：孔喉结构 全孔喉直径表征 致密砂岩 高台子 龙26外扩区 龙虎泡油田 松辽盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]