塔深1井钻井液技术

塔深1井是一口特深科学探索井,设计井深8000 m,完钻井深8408 m,目的层为寒武系。该井钻遇地层复杂,易发生漏失、扩径、坍塌及卡钻等事故,为提高超深井钻井液携岩性能,针对不同开次、优选钻井液类型,一开采用CMC-HV膨润土钻井液以保护井口;二开使用低固相聚合物钻井液,确保大排量,低黏切,强包被,定时或定进尺短起下,从而有效避免阻卡;三开井段使用聚合物磺化防塌钻井液,预防了井壁垮塌和钻屑分散,增强了钻井液的抗温、抗盐水侵能力。四开、五开使用抗高温屏蔽聚磺钻井液技术,克服了高温高压、塌、卡、有进无出严重井漏、固相侵入、膏盐污染、大环空携砂等技术难题,该井的成功完钻为同类井提供了经验。

Drilling fluid technology of Well Tashen-1

Well Tashen-1 is an ultra-deep scientific exploratory well,with its designed depth being 8000m and completed depth 8408m,and its target formation in the Cambrian system.Accidents,such as leakage of drilling fluid,collapse,enlargement of the hole diameter,jamming of the drilling tool,easily occur during drilling the well due to its location in complex strata.In order to improve the solid carrying capacity of drilling fluid of ultra-deep wells,drilling fluid types are selected based on different times of spud drilling.CMC-HV bentonite drilling fluid is used in the first spud drilling to protect the well head.Low solids polymer drilling fluid is used in the second spud drilling to ensure large displacement,low shear viscosity,strong encapsulation,and on-time short trip in definite drilling footage,so as to effectively avoid tool sticking.The polymer sulfonated anti-collapse drilling fluid is used in the third spud section of the well,which helps strengthen the inhibition of the drilling fluid system,avoid wellbore collapse,and improve the temperature-and salt-resistant capacities of drilling fluid.The sulphonic polymer drilling fluid technology with shielding and high temperature resistant properties is applied to the fourth and fifth spud section and helps tackle the technical problems of high temperature,high pressure,collapse,sticking,bad leakage,solid invasion,gypsum-salt pollution,and annular sand-carrying,providing good experience for drilling and completing ultra-deep wells.