姬塬油田长8油藏注聚井高压欠注机理及处理对策分析  

Analysis on the high pressure under-injection mechanism and treatment countermeasures of polymer injection wells in Chang 8 reservoir of Jiyuan Oilfield

作　　者：王光义 姜庆 樊勇杰 王国丞 巨江涛 张倩 WANG Guangyi;JIANG Qing;FAN Yongjie;WANG Guocheng;JU Jiangtao;ZHANG Qian(No.5 Oil Production Plant,Changqing Oilfield Company,PetroChina,Xi’an 710200,Shaanxi;Shaanxi Jingrui Energy Technology Co.Ltd.,Xi’an 710018,Shaanxi)

机构地区：[1]中国石油长庆油田分公司第五采油厂,陕西西安710200 [2]陕西靖瑞能源科技股份有限公司,陕西西安710018

出　　处：《长江大学学报（自然科学版）》2022年第5期73-80,共8页Journal of Yangtze University(Natural Science Edition)

基　　金：国家自然科学基金项目石化联合基金项目“复杂碳酸盐岩储层转向酸与固体转向剂协同转向机理研究”(U1762107)。

摘　　要：针对姬塬油田长8油藏注水井注水压力高压欠注的问题,开展了注水井注水压力升高原因的探究,并进行了注聚井降压增注配方和工艺的探索。通过对注聚井井底返排物成分检测和地层水的分析,明确了引起注聚井高压欠注的因素,一方面是原油中的蜡质、沥青质析出,并与注聚物互相裹夹形成难溶性油垢沉积在油藏的孔道中,导致地层孔隙减小;另一方面则是地层水的不配伍性生成沉淀性钡盐、钙盐等与聚合物在高温高压下相互裹夹形成难溶性污垢,堵塞油藏孔隙使得注水压力增大。针对长8油藏注聚井高压欠注现状,通过对解堵配方的岩心溶解性能、铁离子稳定性、黏土稳定性和解堵性能的室内评价,确定了解堵配方:4%有机复合酸+2%表面活性剂+1.5%聚合物解堵剂+2%黏土稳定剂+1.5%缓蚀剂+1%铁离子稳定剂。通过施工工艺的优化,开发出了适合姬塬油田长8油藏注聚井的解堵体系和工艺,有效解决了有机大分子聚合物和无机垢复合堵塞引起的注水压力升高欠注的问题,为姬塬油田长8层注水井降压增注提供了技术支持。Aiming at the problem of high pressure and under-injection of water injection pressure in water injection wells in Chang 8 reservoir of Jiyuan Oilfield,the reasons for the increase of water injection pressure in water injection wells were investigated,and the formula and technology of pressure reduction and injection increase in polymer injection wells were explored.Based on the composition detection of the flowback materials and the analysis of the formation water at the bottom of the polymer injection wells,the factors causing the high pressure under-injection of the polymer injection wells were clarified.On the one hand,the precipitations of wax and asphaltene in the crude oil were wrapped with the polymer injection to form insoluble oil scale and deposit in the pores of the reservoir,resulting in the reduction of the formation pores;On the other hand,the products of precipitated barium salt and calcium salt by incompatibility of formation water were wrapped with polymers under high temperature and high pressure to form insoluble dirt,blocking the reservoir pores and increasing the water injection pressure.In view of the current situation of high pressure under-injection in polymer injection wells of Chang 8 reservoir,through the laboratory evaluation of the core solubility,iron ion stability,clay stability and plugging removal performance of the plugging removal formula,the plugging removal formula was determined as follows:4%organic compound acid+2%surfactant+1.5%polymer plugging removal agent+2%clay stabilizer+1.5%corrosion inhibitor+1%iron ion stabilizer.Through the optimization of construction technology,the plugging removal system and technology suitable for the polymer injection wells in Chang 8 reservoir of Jiyuan Oilfield have been developed,which effectively solves the problem of water injection pressure increase and under-injection caused by the compound blockage of organic macromolecular polymer and inorganic scale.It provides technical support for the pressure reduction and injection increase of w

关 键 词：注水井 高压欠注 注聚物 解堵 降压增注 

分 类 号：TE357[石油与天然气工程—油气田开发工程]