渤海湾月东区块KCl聚合醇钻井液技术

KCl Poly-glycol Drilling Fluid Technology for Block Hainan-Yuedong

介绍了海南-月东区块的地质特征,针对该区块地层压力系数低等特点,采用了低密度、具有强抑制性和良好润滑性的KCl-聚合醇钻井液体系,解决了该区块钻进过程中容易出现的携砂不理想、泥岩井段扩径、固井质量不合格等钻井液技术难题。介绍了利用离心沉淀法测量滤液中K+含量的方法,这种改进的K+含量测量方法,比通过氯离子滴定法测量Cl-含量来推算K+含量更能准确反映钻井液中K+的含量。现场应用结果表明,泥岩井段井径扩大率得到了有效控制,使用密度大幅度下降。

A low density KCl-poly glycol drilling fluid with strong inhibitive capacity and good lubricity is developed for drilling in Block Hainan-Yuedong where low formation pressure is encountered.With this drilling fluid,technical difficulties such as poor hole cleaning,hole enlargement and poor cementing job quality are solved.This paper discusses the measurement of potassium ion concentration in mud filtrate with centrifugal sedimentation method.This method,compared with the old method which uses the measurement of chloride content to calculate the concentration of potassium,is much more accurate.Field application of the KCl-poly glycol drilling fluid minimizes hole enlargement in claystone section,and the density of drilling fluid is to some extent reduced.