挥发性致密油藏孔隙结构及高温高压三相相渗实验  

Experimental study on pore structure and high-temperature and high-pressurethree-phase relative permeability of volatile tight oil reservoirs

作　　者：罗波波[1] 刘峰刚[1] 王瑞飞[2] 尹帅[2] 张泽[2] 董浩然 LUO Bobo;LIU Fenggang;WANG Ruifei;YIN Shuai;ZHANG Ze;DONG Haoran(Exploration&Development Research Institute of Zhongyuan Oilfield Company,SINOPEC,Puyang,Henan 457001,China;Xi’an Shiyou University,Xi’an,Shaanxi 710065,China)

机构地区：[1]中国石化中原油田分公司勘探开发研究院,河南濮阳457001 [2]西安石油大学,陕西西安710065

出　　处：《石油地质与工程》2023年第3期69-75,81,共8页Petroleum Geology and Engineering

基　　金：国家自然科学基金项目“致密油循环水力压裂裂缝形成及渗流力作用机理研究”(51974253);陕西省教育厅重点项目“致密砂岩储层层理缝表征方法及渗流-应力时变耦合机理(18JS084)”;陕西省高校科协青年人才托举计划(20180703)资助。

摘　　要：东濮凹陷文南地区古近系沙三中段油藏属于典型的深层、高温、高压挥发性油藏,存在注水见效差的问题。通过应用恒速压汞、高温高压相渗测试及Stone1模型对东濮凹陷深层致密砂岩储层的孔隙结构特征、不同渗透率样品在高温、高压及不同驱替流体(原始油样/贫气原油/富气原油)条件下的可动流体特征进行了系统研究。研究结果显示,样品喉道半径分布在0.745~5.042μm;孔隙半径分布在16.970~171.035μm;孔喉半径比分布在40~278,最大连通喉道半径分布在1.041~12.672。不同样品喉道呈“多峰”分布且喉道半径普遍低于10μm。不同样品孔隙半径分布一致,存在135μm和165μm两个峰值。样品孔喉半径比也具有“双峰”特征,两个峰值分别为60和130。孔喉半径比越大,样品的渗透率越低。当喉道半径值大于1μm时,喉道对渗透率有明显的贡献。基于Stone1模型构建了致密储层三相渗透率曲线,油、气、水各自的相对渗透率都随着饱和度的增加而增加;油的相对渗透率是油、气、水三相饱和度的函数。最终,计算并绘制了样品在140℃及不同测试压力条件下的相渗三角图。结果显示,每一种原油存在一个最佳驱替压力时,可动流体空间最大。此外,当原油中含气量较少时,可动流体空间会随压力的增大而增大;当原油中含气量较多时,压力对低渗油藏的可动流体空间的影响不明显。当驱替流体为富气原油时,可动流体空间最大。这是由于,气体的加入占据了原来是束缚水或束缚油的一部分空间,气体的可流动性更强,因此其可动流体空间增加。The reservoir in the middle section of the third member of Paleogene Shahejie formation in Wennan area of Dongpu Sag is a typical deep,high temperature and high-pressure volatile oil reservoir,which has the problem of poor water injection efficiency.The pore structure characteristics of deep tight sandstone reservoirs in Dongpu Sag and the movable fluid characteristics of samples with different permeability under high-temperature,high-pressure and different displacement fluids(original oil sample/lean gas crude oil/rich gas crude oil)were studied by using constant velocity mercury injection,hig-temperature and high-pressure phase permeability test and Stone1 model.The research results show that the throat radius of the sample is 0.745~5.042μm,pore radius is 16.970~171.035μm,the ratio of pore throat radius is 40~278,and the maximum connecting throat radius is 1.041~12.672.Throats of different samples show"multi-peak"distribution and throat radius is generally less than 10μm。The pore radius distribution of different samples is consistent,with two peaks of 135μm and 165μm.The pore throat radius ratio of the sample also has a"double-peak"feature,with two peaks of 60 and 130 respectively.The larger the pore throat radius ratio,the lower the permeability of the sample.When the throat radius value is greater than 1μm,the throat is favorable for permeability.Three-phase permeability curve of tight reservoir is constructed based on Stone1 model.The relative permeability of oil,gas and water increases with the increase of saturation.The relative permeability of oil is a function of the three-phase saturation of oil,gas and water.Finally,the permeability triangle diagram of the sample at 140℃and different test pressures was calculated and drawn.The results show that when there is an optimal displacement pressure for each crude oil,the movable fluid space is the largest.Besides,when the gas content in crude oil is small,the movable fluid space will increase with the increase of pressure.When the gas content in the

关 键 词：东濮凹陷 挥发性油藏 孔隙结构 相渗三角图 可动流体 

分 类 号：TE311[石油与天然气工程—油气田开发工程]