单相缓速酸酸蚀裂缝导流规律  

Development and Corrosion Inhibition Mechanisms of a Corrosion Inhibitor for Self-Diverting Acids

作　　者：崔波[1] 冯浦涌[1] 姚二冬 荣新明[1] 周福建[2] CUI Bo;FENG Puyong;YAO Erdong;RONG Xinming;ZHOU Fujian(COSL Production Optimization Department,Tianjin 300450;Institute of Unconventional Oil and Gas Science and Technology,China University of Petroleum(Beijing),Beijing 102249)

机构地区：[1]中海油田服务股份有限公司油田生产事业部,天津300450 [2]中国石油大学(北京)非常规油气科学技术研究院,北京102249

出　　处：《钻井液与完井液》2024年第2期270-278,共9页Drilling Fluid & Completion Fluid

基　　金：国家自然科学基金"纳米乳液在致密砂岩储层中的吸附特性及其解水锁机制研究"(52004306);国家科技重大专项“中亚和中东地区复杂碳酸盐岩油气藏采油采气关键技术研究与应用”(2017ZX05030005)。

摘　　要：低渗碳酸盐岩酸压成功的关键在于酸压后形成可在地层闭合压力下保持高导流能力的酸蚀裂缝。单相缓速酸是一种具有纳米结构、低伤害、低摩阻及高缓速性能的新型酸液体系,应用潜力大,但其酸蚀裂缝导流规律尚不明确。以光滑岩板和粗糙岩板为实验对象,以盐酸、胶凝酸和乳化酸为对比,利用酸液刻蚀和酸蚀裂缝导流实验、表面形貌扫描和连续强度测试仪,研究了酸液类型、交替注入级数、注入速度、黏度比、反应时间、岩板类型对导流能力的影响。结果表明:单相缓速酸相对于盐酸、胶凝酸和乳化酸,可形成强沟道型刻蚀形貌,差异化溶蚀程度高,岩板强度损伤减缓,在高闭合压力下可保持较高的导流能力。提高酸液交替注入级数(≥3级)、注入速度、黏度比(黏度差≥50 mPa·s)及岩板初始表面粗糙度,有助于形成优势酸液流通通道。单相缓速酸实现高导流酸蚀裂缝机理为:(1)黏性指进形成差异化刻蚀沟道;(2)主蚓孔滤失形态及“虹吸”效应减缓裂缝表面强度损伤。Self-converting acids are widely used in the acid fracturing of carbonate reservoirs.Conventional corrosion inhibitors used in self-converting acids have,because of the unique molecular structure of the viscoelastic surfactants(VES),poor compatibility with other components,thereby drastically reducing their corrosion inhibitive performance.In this study,two pyridine quaternary ammonium salt corrosion inhibitors,SI-1 and SI-2,are synthesized with 1-chloromethylnaphthalene,4-ethyl pyridine,benzyl chloride and 2,3-cyclopentenopyridine.Using corrosion tester and rheometer,the corrosion inhibitive performance of SI-1 and SI-2 in self-diverting acids is studied.Also studied are the effects of SI-1 and SI-2 on the viscosity of the diverting acids.Using SEM,EDS,atomic force microscope and X-ray photoelectron spectroscopy,the surface morphology and chemical components of the steel plates before and after corrosion are analyzed from a microscopic point of view.The corrosion inhibition mechanisms of SI-1 and SI-2 are investigated using molecular dynamic simulation method.The results of these studies show that the two pyridine quaternary ammonium corrosion inhibitors have good corrosion inhibitive performance in self-converting acids and they only very slightly affect the viscosity of the self-converting acids being studied.The two corrosion inhibitors have wide applicability and are costeffective.Compared with SI-1,SI-2 is a better corrosion inhibitor.At 90℃,the corrosion rate of the steel plates in 1%corrosion inhibitor is 1.04 g/(m^(2)·h),at 120℃,the corrosion rate is 7.43 g/(m^(2)·h),the final viscosity of the VES residual acids is 190 mPa∙s or higher,and the operation cost can be reduced by 20%.When adding 1%corrosion inhibitor SI-1 or SI-2 into the self-convert acid,no apparent corrosion can be found on the surface of the steel plates,and the Fe content is greatly increased,indicating a significant reduction in surface roughness.When SI-2 is used,the Fe content is increased from 86%to 94%,and the Ra value reduc

关 键 词：单相缓速酸 碳酸盐岩 酸蚀裂缝导流 差异化酸蚀 岩板强度损伤 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]