塔河油田深井超深井钻井液技术难点与对策

塔河油田油气埋藏深．钻遇地层多而且复杂．钻井过程中易发生钻井液漏失、井眼坍塌、卡钻等井下复杂情况和事故，严重影响了勘探开发的进程。通过技术攻关和技术引进，成功解决了塔河油田三叠系、石炭系硬脆性泥页岩地层易坍塌、奥陶系大型裂缝溶洞地层钻井液漏失、巨厚盐膏层塑性蠕变卡钻等制约塔河油田勘探开发的技术难题，使该油田井深6000m左右的开发井建井周期从原来的90d缩短到70d以内，井径扩大率由15％降至10％以内，超深盐膏层钻井成功率从2002年前不足40％提高到现在的100％，经济效益十分显著。

Technical Challenges and Solutions of Drilling Fluid Techniques in Deep and Ultra-Deep Wells in Tahe Oilfield

Oil and gas deposit deep in Tahe Oilfield.As a result, formations encountered vary a lot, mud loss is likely to happen during drilling,and downhole troubles and accidents such as hole sloughing and pipe sticking have severely interfered with the process of exploration and production. After tackling key technical problems and introducing advanced technologies, downhole troubles restricting exploitation of the Tahe Oilfield are successfully solved, for example, wellbore is likely to slough while penetrating hard-crisp shales in the Triassic and the Carboniferous system, drilling fluids lose into large-scale caves in the Ordovician formations, drillstring is stuck in the huge-thick plastic gypsums, etc. Drilling time for a development well of 6000m deep is reduced from 90d to less than 70d, hole enlargement is shortened from 15% to within 10%, drilling successful probability in ultra-deep well is increased from 40% or less in 2002 to current 100%, the economic benefits are remarkable.