TH10410CH2井强抑制性聚胺钻井液技术的应用

Application of Polyamine Drilling Fluid with Strong Inhibitory in TH10410CH2 Well

塔河油田近几年在老井侧钻过程中,造斜点选在石炭系巴楚组或奥陶系桑塔木组。巴楚组地层以褐灰色泥岩为主,桑塔木组地层以灰、绿灰色泥岩为主,夹薄层灰岩。造斜井段中泥岩段较长,受地应力及钻井液的浸泡作用,井壁极易坍塌,钻井施工中起下钻遇阻、卡钻、断钻具等复杂情况经常发生,甚至无法成井。针对巴楚组和桑塔木组复杂泥岩井壁失稳机理开展研究,对水化后力学特性影响进行分析,并形成了聚胺聚磺强抑制性防塌钻井液(XJA-1)技术。在TH10410CH2井泥岩段应用效果表明,新型聚胺强抑制剂具有强抑制性,不仅有利于井壁稳定,而且提高钻井液的稳定性和抗黏土污染能力,处理剂在钻井液中的加量在0.5%～1.0%之间。以聚胺为主要抑制剂形成的强抑制性聚胺聚磺钻井液体系,通过改善泥饼质量,降低滤液的侵入速度,封堵泥页岩中作为钻井液滤液漏失主要通道的微裂缝,阻止和延缓滤液的进入,达到有效支撑井壁,防止泥岩地层垮塌,安全、快速钻井的目的。

During sidetracking of old wells in Tahe oilfield in recent years,kick off point is selected in Bachu formation of Carboniferous system or Sangtamu formation of Ordovician system.Drab gray mudstones are the main lithology in Bachu formation,and gray and green-gray mudstones are the main lithology in Sangtamu formation with thin-bedded limestones.There is long mudstone section among kick off section.Under the action of ground stress and soak of drilling fluid,borehole wall is easy to collapse,and complex situations of tight pull during tripping,drill pipe sticking and drilling rig failure may appear usually and even no well completion.Destabilization mechanism of the complex mudstone borehole wall in Bachu and Sangtamu formations is studied.The effect of mechanical behavior after hydration is analyzed,and polyamine and polysulfonate drilling fluid with strong inhibitory（XJA-1） is formed.Result of the drilling fluid ′s application to the mudstone sections in TH10410CH2 well shows that XJA-1 can not only make borehole wall stable but also enhance stability and antipollution capacity of clay for its strong inhibitory and there are 0.5%-1.0% treating chemical in the drilling fluid.After XJA-1 is applied,safe and quick drilling may be achieved on effective support of the borehole wall and preventing collapse of mudstones formations through improving mud cake quality,reducing invasion velocity of filter liquor,blocking main leakage channel micro-fractures,and inhibiting and retarding entrance of the filter liquor.