无黏土高温高密度油基钻井液

针对塔里木盆地山前构造带井深高温以及地层裂缝发育的特点,研发了油基钻井液关键处理剂,其包括主乳化剂HT-MUL、辅乳化剂HT-WET、提切剂ZNTQ-1。乳化剂通过抗高温的亲水亲油官能团,在油水界面形成具有很强黏弹性的界面膜来提高乳化能力;基于超分子原理,提切剂通过在油水界面的氢键作用提高乳状液的凝胶强度,达到替代有机土的效果。以乳化剂和提切剂为核心处理剂配制的无黏土高温高密度油基钻井液,抗温达220℃,密度达2.50 g/cm3,老化后乳化稳定性好,不出现分层现象,高温高压滤失量小于10.0 m L,具有极好的滤失性,可通过柴油配制得到。无黏土高温高密度油基钻井液克服了以往有机土油基钻井液高温易降解失效和高密度下流变性差的缺点;同时提切剂取代有机土,除了能进一步加快钻速外,还能降低储层损害程度,是目前油基钻井液技术的领先技术,具有极好的应用前景。

High density clay-free oil-based drilling fluid with high temperature tolerance

Considering the characteristics of deep well,high temperature and formation fracture in Tarim piedmont tectonic belt,some key reagents of oil-based drilling fluid,such as primary emulsifier HT-MUL,auxiliary emulsifier HT-WET,and viscosifier ZNTQ-1 were prepared.The improvement of emulsion ability results from the efficient viscoelastic film generated by the hydrophilic group and hydrophobic group with high temperature tolerance in the oil-water interface.Based on the supramolecular chemistry,ZNTQ-1 improves the gel strength with hydrogen bond in the oil-water interface and has the effect of clay in drilling fluid.Highdensity clav-free oil-based drilling fluid,which has the characteristics of anti-temperature 220 ℃,density 2.50 g/cm3,is prepared by the key agent emulsifiers and viscosifier.The oil-based drilling fluid system,whose base oil is diesel,has excellent emulsion stability and its HTHP filtration is less than 10.0 ml after aging.Comparing with the conventional clay oil-based drilling fluid,the clay-free oil-based drilling fluid has excellent anti-temperature degradation,lower formation damage,high drilling speed and rheological property under high density.Therefore,the clay-free oil-based drilling fluid is an advanced oil-based drilling fluid technology now and has excellent application prospect.