低渗透油藏水凝胶调驱剂的制备及封堵性能评价  

Preparation and Plugging Performance of Hydrogel Profile Control Agent for Low Permeability Reservoir

作　　者：吴天江[1,2] 鄢长灏[1,2] 赵海峰 高雨[1,2] WU Tianjiang;YAN Changhao;ZHAO Haifeng;GAO Yu(Oil and Gas Technology Research Institute,Changqing Oilfield Branch Company,PetroChina,Xi’an,Shaanxi 710018,P R of China;National Engineering Laboratory of Low Permeability Oil and Gas Field Exploration and Development,Xi’an,Shaanxi 710018,P R of China)

机构地区：[1]中国石油长庆油田分公司油气工艺研究院,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018

出　　处：《油田化学》2023年第1期51-55,67,共6页Oilfield Chemistry

基　　金：国家科技重大专项课题“低渗-超低渗油藏提高储量动用关键工艺技术”(项目编号2017ZX05013-005)。

摘　　要：为了提升低渗透油藏调驱剂的注入性和封堵性,开发了一种水凝胶体系,以成胶强度为指标优选了水凝胶配方及制备条件,并评价了其封堵性能和调驱性能。优化的水凝胶配方如下:丙烯酸用量为20 g/L、丙烯酰胺用量为5 g/L、过硫酸铵用量为0.07 g/L、改性淀粉用量为5 g/L、交联剂N,N-亚甲基双丙烯酰胺用量为0.08 g/L,最佳合成条件为中和度75%、反应温度9℃,所生成水凝胶的成胶强度为35~37 Pa·s。通过机械剪切、烘干得到微米级粒径的水凝胶调驱剂。封堵实验表明,质量浓度为0.1~0.7 g/L的水凝胶调驱剂对渗透率为1600×10^(-3)~1900×10^(-3)μm^(2)的填砂管的封堵率在92%以上,随着水凝胶质量浓度的增大,阻力系数增大,注入压力爬升较快,但残余阻力系数和封堵率变化较小。水凝胶作为驱油剂使用建议采用低浓度注入,在水驱基础上可提高采收率10%左右。低浓度微颗粒水凝胶调驱剂可有效解决低渗透油藏调驱注入性和封堵性的矛盾。综合考虑注入性、封堵性和驱油性能,推荐水凝胶水溶液现场应用的质量浓度为0.1~0.3 g/L。In order to improve the injecting and plugging properties of low permeability reservoirs,a hydrogel system was developed,the formulation and preparation conditions of the hydrogel were optimized based on the gel strength,and the plugging and flooding performance were evaluated.The optimized hydrogel formula was as follows,the dosage of acrylic acid,acrylamide,ammonium persulfate,modified starch and N,N-methylene bis acrylamide was 20 g/L,5 g/L,0.07 g/L,5 g/L,0.08 g/L,respectively,and the best synthesis condition was that neutralization degree was 75%,initiation temperature was 9℃.The gel strength of the obtained hydrogel was 35—37 Pa·s.Hydrogel profile control agent with micrometer size was obtained by mechanical shearing and drying.The plugging experiment showed that the plugging rate of hydrogel with the mass concentration of 0.1—0.7 g/L to the sand-filled pipe with the permeability of 1600×10^(-3)—1900×10^(-3)μm^(2) was more than 92%.With the increase of the mass concentration of hydrogel,the drag coefficient increased,and the injection pressure increased rapidly,but the residual resistance coefficient and plugging rate changed little.It was recommended to use low concentration injection of hydrogel as oil displacement agent,which could improve oil recovery by about 10%on the basis of water flooding.Low concentration micro particle hydrogel could effectively solve the contradiction between injectivity and plugging of profile control in low permeability reservoirs.Considering the injection and plugging and flooding properties,the recommended mass concentration of hydrogel was 0.1—0.3 g/L.

关 键 词：水凝胶 成胶强度 体系筛选 封堵性能 低渗透油藏 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]