氯化钾聚合醇强抑制封堵钻井液体系在H2井的应用

H2井作为一口在北部湾盆地WX勘查区海中凹陷斜坡带勘探的重点探井意义重大。在该区块浅部地层钻进时易发生缩径垮塌、断层漏失问题；中深部地层因存在异常高压区域而易垮塌。H2井同时还是一口大斜度定向井。在此井应用了氯化钾聚合醇强抑制封堵钻井液体系，改善和延缓泥页岩微裂缝发育所导致的井壁缩径、垮塌，有效控制了钻井液的悬浮携带性，并提高了泥饼质量，保证了钻井顺利进行。介绍了其具体应用及施工效果，表明该体系具有流变性好、携岩能力强、抑制润滑性突出、防塌效果显著等优点，同时兼顾地质与工程要求。

Application of KCl Polyol Drilling Fluid System in Well H2

Well H2 located at the west slope of Haizhong Sag of Beibuwan Basin, is meaningful to the oil and gas exploration in the Weixi Block of Sinopec. During drilling in this area, hole diameter reduction, collapse and drilling mud leakage by faults easily occur at the shallow, and wellbore collapse is more often at the medium-deep due to the existence of abnormal high pressure. As for Well H2, these drilling risks are more likely occurred because it is a high-inclination directional well. The application of KCl polyol drilling fluid system, a strong inhibition and plugging drilling fluid, improved and retarded the hole diameter reduction, collapse caused by micro fractures in the shale, effectively controlled the solid carrying and suspending of drilling fluid, enhanced the quality of mud cake, ensured the drilling operation successfully. This paper detailed introduces the application and the effects. This drilling fluid system have the advantages of good rheological property, high carrying capacity, good inhibition of lubrication performance and significant collapse-protecting effect. It can also meet the requirements of both geology and engineering.