基于底水仿真模型油藏化学驱后CO_(2)吞吐增油效果——以大港油田底水油藏为例  

Study on CO_(2) huff and puff effect of increasing oil production after chemical flooding based on bottom water reservoir simulation model:Take bottom water reservoir of Dagang Oilfield as an example

作　　者：李毓 卢祥国[1] 李鸿儒 张杰[2] 王晓燕[1,2] 崔丹丹[2] 郐婧文 LI Yu;LU Xiangguo;LI Hongru;ZHANG Jie;WANG Xiaoyan;CUI Dandan;KUAI Jingwen(MOE Key Laboratory of Enhancing Oil and Gas Recovery,Northeast Petroleum University,Daqing 163318,China;Oil Production Technology Research Institute of Dagang Oilfield Co Ltd,Tianjin 300280,China;Production Optimization,China Oilfield Services Limited,Tianjin 300459,China)

机构地区：[1]东北石油大学提高油气采收率教育部重点实验室,黑龙江大庆163318 [2]中国石油大港油田采油工艺研究院,天津300280 [3]中海油田服务股份有限公司油田生产事业部,天津300459

出　　处：《大庆石油地质与开发》2022年第5期101-111,共11页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项“大型油气田及煤层气开发:复杂断块油藏化学驱技术现场应用研究”(2016ZX05010-004);中国石油天然气股份有限公司重大科技专项“复杂断块油田提高采收率关键技术研究”(2018E-11-07)。

摘　　要：大港底水油藏储层具有高孔隙度、高渗透率和高原油黏度的特点,强注强采造成底水快速推进和突破,现有的水平井水平段完井方式给堵水作业带来极大困难,亟待采取大幅度提高采收率措施。通过基于底水仿真模型聚驱后CO_(2)驱和CO_(2)吞吐的物理模拟方法,对底水油藏增油效果进行研究。结果表明:底水油藏化学驱后CO_(2)吞吐可以进一步提高采收率,3轮次吞吐后采收率增幅为5%,其中前2轮增油效果较好;与化学驱后CO_(2)吞吐相比较,水驱后直接CO_(2)吞吐采收率增幅较大,3轮次吞吐采收率增幅超过20%;CO_(2)注入底水油藏和闷井后部分CO_(2)会溶解于油和水中,发挥增能、降黏和助喷等作用,有助于提高原油采收率;过低避水高度会引起底水锥进和油井水淹,导致驱油剂从水井进入底水层,进而降低底水油藏开发效果;水驱后剩余油纵向上主要分布在远离注入端的低渗透层,平面上主要分布在远离注采井主流线两翼部位。研究成果为化学驱后剩余油的进一步挖潜提供了科学依据。Bottom water reservoirs in Dagang Oilfield are characterized by high porosity,high permeability and high oil viscosity.Strong injection and strong production result in rapid advance and breakthrough of bottom water.Existing completion methods of horizontal well section bring much difficulty to water plugging operation,so it is ur-gent to take measures to greatly enhance oil recovery.Based on the bottom water simulation model,physical simula-tion method of CO_(2) flooding and CO_(2) huff and puff after polymer flooding is used to study the oil production increase effect of bottom water reservoir.The results indicate that CO_(2) huff and puff after chemical flooding can further en-hance oil recovery.After 3 rounds of huff and puff,recovery rate is increased by about 5%,and oil increment effect of the first 2 rounds is better.Recovery of direct CO_(2) huff and puff after water flooding is higher than that after chem-ical flooding,and recovery increase after 3 rounds of huff and puff is higher than 20%.After CO_(2) injected into bot-tom water reservoir and soak,part of CO_(2) will dissolve in oil and water,which can play the role of increasing ener-gy,reducing viscosity and assisting production,being helpful to enhance recovery.Too low water avoidance height may cause bottom water coning and producer watered out,causing displacement agent entering into bottom water layer from injector and then weaken development effect of bottom water reservoir.Remaining oil after water flooding is mainly vertically distributed in low permeability layer far away from injection end,and areally mainly distributed in two wings away from main streamline of injection-production wells.The research results provides scientific evi-dences for further potential tapping of remaining oil after chemical flooding.

关 键 词：大港油田底水油藏 化学驱 CO_(2)吞吐 CO_(2)驱 物理模拟 机理分析 

分 类 号：TE357.4[石油与天然气工程—油气田开发工程]