高温碳酸盐岩储层酸压固态延迟酸在裂缝中作用规律数值模拟  

Numerical simulation of solid⁃delayed acid behavior in fractures of high⁃temperature carbonate reservoir acid fracturing

作　　者：罗攀登 张士诚[1] 张雄[1,2] 牟建业[1] 郑海钱[3] 卢盼盼[1] LUO Pandeng;ZHANG Shicheng;ZHANG Xiong;MOU Jianye;ZHENG Haiqian;LU Panpan(College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Petroleum Engineering Technology,Sinopec Northwest Oil Field Company,Urumqi 830011,China;Northeast Sichuan Gas Field of PetroChina Southwest Oil&Gas Field Company,Dazhou 635000,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]中国石化西北油田分公司石油工程技术研究院,新疆乌鲁木齐830011 [3]中国石油西南油气田公司川东北气矿,四川达州635000

出　　处：《大庆石油地质与开发》2025年第2期79-88,共10页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油化工股份有限公司西北油田分公司重大科技项目“顺北稳产力学基础研究”(34400007-22-ZC0607-0056)。

摘　　要：酸压是低渗透碳酸盐岩储层增产改造的主要方式。在高温碳酸盐岩储层中常规酸作用距离短,常使用自生酸提高酸液作用距离,自生酸中的固态延迟酸在油田使用较广,但考虑温度影响固态延迟酸作用规律的模拟与研究较少。针对该问题,首先建立固态延迟酸生酸模型;其次,通过物质守恒、能量守恒、动量守恒及酸岩反应动力学原理,构建酸压中固态延迟酸作用模型;最后,采用数值求解方法,编制程序进行模拟计算。结果表明:固态延迟酸在无反应条件下生酸浓度可达到纯HCl的11.4%(质量分数),在裂缝中流动、反应条件下,生酸浓度约为纯HCl的6%(质量分数);在近井地带(距井40m)滤失降温作用导致酸蚀缝宽变化明显;中深部裂缝,有无考虑酸岩反应生热使得酸液温度相差最高40℃;相较于交联酸,固态延迟酸具有缓慢释放、增加活酸作用距离的优势;在典型施工条件组合下,预测固态延迟酸作用距离可达140~180m。研究成果可为高温碳酸盐岩储层酸压中固态延迟酸的应用提供了理论依据。Acid fracturing is a main stimulation method for low-permeability carbonate reservoirs.Conventional acid has short action distance in high-temperature carbonate reservoirs,so self-generated acid is often used to increase acid fluid action distance.Solid-delayed acid in self-generated acid is widely used in oilfields,but lack of simula-tion and research on solid-delayed acid behavior considering temperature impact.Aiming at this problem,a model for solid-delayed acid generation is firstly established.Secondly,a model of solid-delayed acid action in acid frac-turing is constructed based on principles of conservation of matter,conservation of energy,conservation of momen-tum and kinetics of acid-rock reaction.Lastly,numerical solution method is used in programming for simulation cal-culation.The results show that,generated acid concentration of solid-delayed acid reaches 11.4%(mass fraction)of pure HCl in non-reaction condition,and is about 6%(mass fraction)of pure HCl in flowing and reaction condition in fractures.Filtration and cooling in near-well zone(40 m away from well)cause significant variation of acid etched fracture width.For middle-deep fractures,whether or not consider heat generation of acid-rock reaction result in maximum acid temperature difference of 40℃.Compared to cross-linked acid,solid-delayed acid has the advan-tage of slow release and increasing the distance of active acid action.With typical combination of operation condi-tions,predicted distance of solid-delayed acid action can reach 140~180 m.The research provides theoretical ba-sis for application of solid-delayed acid in acid fracturing of high-temperature carbonate reservoirs.

关 键 词：固态延迟酸 生酸规律 裂缝温度场 建模 酸压 活酸作用距离 碳酸盐岩储层 

分 类 号：TE357.2[石油与天然气工程—油气田开发工程]