钻井液降滤失剂与水泥浆接触污染机理及防止对策  

Mechanisms of Cement Slurry Contamination by Drilling Fluid Filtration Agents and Measures of Preventing the Contamination

作　　者：杨兆亮 刘森 沈欣宇 罗越耀 张玉婷 YANG Zhaoliang;LIU Sen;SHEN Xinyu;LUO Yueyao;ZHANG Yuting(Engineering Research Institute of Southwest Oil&Gas Field Company,petrochina,Deyang,Sichuan 618000)

机构地区：[1]中国石油天然气股份有限公司西南油气田分公司工程技术研究院,四川德阳618000

出　　处：《钻井液与完井液》2024年第6期792-799,共8页Drilling Fluid & Completion Fluid

基　　金：中石油集团公司重大专项“海相碳酸盐岩油气规模增储上产与勘探开发技术研究”(2023ZZ16)。

摘　　要：为了解决钻井液对低密度水泥浆的污染问题,必须掌握钻井液处理剂对水泥浆的微观结构、聚集稳定性等性能的影响。选用性能显著的钻井液用抗高温降滤失剂LS-2A作为研究对象,采用单因素分析法研究了LS-2A对水泥浆的性能影响。实验研究表明,LS-2A中的羧酸、羟基、磺酸基官能团会与水泥浆中的Ca2+发生交联生成絮凝物,使水泥石水化产物形成胶凝网状结构,凝胶包裹吸附水泥浆中的自由水,降低水泥浆流动性,抑制水泥浆的早期水化反应速度,降低水泥石的抗压强度。针对LS-2A引起的污染问题,通过双1,6-亚己基三胺五甲叉膦酸(BHMTPMPA)与氧化锌(ZnO)以质量比3∶1复配而成一种抗污染剂。掺入5%抗污染剂后水泥浆流动度由14 cm提升至24 cm。在205℃×130 MPa×110 min条件下,水泥浆与钻井液的混合浆体(7∶3)的稠化时间仅51 min,未能满足固井要求。而使用了抗污染剂后的水泥浆、钻井液、隔离液(7∶2∶1)的混浆稠化时间大于300 min。BHMTPMP与ZnO通过与水泥浆中Ca2+反应,在水泥颗粒表面形成保护膜并产生电性斥力作用,成功解决了LS-2A造成的水泥浆污染问题,并在蓬深6井注水泥塞固井施工中成功应用。The understanding of the effects of drilling fluid additives on the microstructure and agglomeration stability of cement slurries is necessary to combat the contamination of low-density cement slurries by drilling fluids.Using single-factor analysis,the effects of LS-2A,a drilling fluid filtration reducer,on the properties of a cement slurry are studied.Experimental results show that the functional groups in the molecules of LS-2A,such as the carboxyl,the hydroxyl and the sulfonic group,can react with the Ca2+ions in the cement slurry through crosslinking to form flocs,resulting in the formation of a gel network structure in the set cement.The gel structure wraps up and absorbs the free water in the cement slurry,reducing the fluidity of the cement slurry,inhibiting the speed of the early stage hydration of the cement slurry,and reducing the compressive strength of the set cement.To deal with the contamination of LS-2A to the cement slurry,a contamination inhibitor is developed by mixing bis(hexamethylene triamine penta(methylene phosphonic acid))(BHMTPMPA)and zinc oxide(ZnO)in a mass ratio of 3∶1.By adding 5%of the contamination inhibitor into the cement slurry,the fluidity of the cement slurry is increased from 14 cm to 24 cm.At conditions of 205℃×130 MPa×110 min,the thickening time of the mixture of the cement slurry and the drilling fluid(7∶3)is only 51 min,unable to satisfy the needs of well cementing.After using the contamination inhibitor,the thickening time of the mixture of the cement slurry,the drilling fluid and a spacer(7∶2∶1)is longer than 300 min.The contamination inhibitor BHMTPMPA and ZnO,by reacting with the Ca2+ions in the cement slurry,generate a protective film on the surfaces of the cement particles and produce an electric repulsion,thereby successfully prohibiting the contamination to the cement slurry by LS-2A.The contamination inhibitor has been successfully used in running cement plug and cementing the well Pengshen-6.

关 键 词：降滤失剂 污染 机理 抗污染剂 钻井液 

分 类 号：TE256[石油与天然气工程—油气井工程]