准噶尔盆地南缘下组合超深井钻井技术研究与应用

Research of Drilling Technology for Ultra-deep Well of Lower Assemblage in the Southern Margin of Junggar Basin and Its Application

准噶尔盆地南缘下组合勘探程度低,针对井身结构设计难度大,钻井液体系不完善,钻井提速难度大等难点,为了确保独山1井的顺利实施,利用地震资料建立了地层压力剖面并结合地层情况,确定了四开备五开的井身结构方案;通过室内试验研究,形成了抗高温高密度钻井液体系;利用测井资料建立岩石力学特性剖面,优选出高效钻头序列。实钻结果表明,独山子背斜纵向上存在多套异常高压地层;抗高温高密度钻井液体系能够满足下组合安全钻井的需要;PDC钻头提速显著,全井平均机械钻速达到2.28m/h。独山1井的钻探为准噶尔盆地南缘下组合的勘探积累了宝贵的经验。

The lower assemblage in the southern margin of Junggar Basin had low exploration degree,it was difficult for wellbore structural design and there existed the problems of imperfect drilling fluid system and difficult for raising drilling speed.In order to ensure successful operation of Well Dushan 1,a formation pressure profile was established by using seismic data and based on the stratigraphy,a scheme of 4th spud to 5th spud drilling was determined.Through laboratory experimental study,a high density and high temperature resistance drilling fluid system was established.Logging data were used to establish a profile of rock mechanic properties for selecting the high efficiency bit series.The actual drilling result shows that there exist many sets of abnormal high pressure formations in Dushanzi Anticline,the drilling fluid system could meet the needs of high pressure high temperature conditions of safe well drilling in the lower assemblage,it is obvious of raising speed from PDC bit,the average penetration rate reaches 2.28m/h.The drilling of Well Dushan 1 accumulates valuable experiences for the exploration of lower aassemblage in the southern margin of Junggar Basin.