高压低渗透油藏回注天然气驱微观驱油机理  

Microscopic oil displacement mechanism of nature gas flooding in high-pressure and low-permeability reservoirs

作　　者：崔茂蕾 王锐[1,2,3] 吕成远 伦增珉[1,2,3] 赵淑霞[1,2,3] 唐永强 CUI Maolei;WANG Rui;LÜChengyuan;LUN Zengmin;ZHAO Shuxia;TANG Yongqiang(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing City,100083,China;Key Laboratory of Marine Oil and Gas Reservoir Production,SINOPEC,Beijing City,100083,China;Petroleum Exploration and Development Research Institute,SINOPEC,Beijing City,100083,China)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室,北京100083 [2]中国石化海相油气藏开发重点实验室,北京100083 [3]中国石化石油勘探开发研究院,北京100083

出　　处：《油气地质与采收率》2020年第1期62-68,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项“鄂尔多斯盆地致密低渗油气藏注气提高采收率技术”（2016ZX05048003）

摘　　要：高压低渗透油藏衰竭开采后地层能量不足,原油脱气导致产气量较高,而产出气回注从经济和技术上来说是可行的。为了研究该类油藏衰竭开采后回注天然气微观驱油机理,在高温高压条件下开展天然气驱影响因素研究,揭示衰竭开采和注水开发对天然气驱油效果的影响规律。应用自主研发的高温高压微观可视化实验装置,在玻璃刻蚀的多孔介质仿真模型上,开展不同条件下天然气微观驱替实验。结果表明:天然气驱能够缓解在衰竭开采过程中原油脱气造成的贾敏效应;在目标油藏条件下,天然气驱油机理以驱替作用为主、溶解抽提作用为辅。水能够屏蔽天然气与原油的接触,在天然气未波及区内,原油被水封存难以被动用;在波及区内,天然气能够剥离水膜,与原油直接接触,在溶解抽提的作用下驱替原油。高压低渗透油藏天然气驱能够在衰竭开采的基础上进一步提高原油采收率。After depleted production of high-pressure and low-permeability reservoirs,the formation energy is insufficient,which leads to the increase of gas production because of oil degassing. Therefore it is feasible to reinject the produced gas from economical and technical aspects. In order to clarify the microscopic oil displacement mechanism of reinjected natural gas flooding after the depleted production of this kind of reservoir,the factors influencing natural gas flooding is analyzed under high-temperature and high-pressure conditions so as to reveal the influence of depleted production and water flooding on natural gas flooding effect. Using self-developed high-temperature and high-pressure micro-visualization device,the microscopic gas displacement experiments under various conditions are carried out on the glass-etched porous medium simulation model. The results indicate that natural gas flooding can reduce the Jamin effect caused by degassing of oil during depleted production.Under the target reservoir conditions,the gas flooding mechanism is dominated by displacement,and the dissolution extraction is supplemented. Water barrier prevents the contact between gas and oil.In unswept area of natural gas,the residual oil is difficult to be produced because of water barrier,in swept area,natural gas can peel off water film gradually to contact with oil,and displace oil by dissolution and extraction. Natural gas flooding in high-pressure and low-permeability reservoirs can further enhance oil recovery after depleted production.

关 键 词：高压低渗透 衰竭开采 天然气驱 可视化实验 微观驱油机理 

分 类 号：TE357.7[石油与天然气工程—油气田开发工程]