水乳环氧树脂对水硬性凝胶隔段综合性能的影响

Influence of Waterborne Epoxy Resin Emulsion on Properties of Hydraulic Gel Packing

针对水硬性凝胶形成的固化隔段强度低、胶结差、孔缝裂隙多,在精细控压钻井起下钻过程中难以有效封堵油气层防止流体上窜的难题,室内采用一种水乳环氧树脂CQ-WERE和配套固化剂CU-900作为性能改善剂加入水硬性凝胶工作液中,研究其对水硬性凝胶工作液流变性能和固化隔段力学性能影响,并分析了水乳环氧树脂改善凝胶隔段力学性能的机理。研究结果表明:水乳环氧树脂与水硬性凝胶工作液相容性好,对凝胶工作液的流动度和流变参数影响小,水硬性凝胶工作液的稠化时间随着水乳环氧树脂加量的增加而缩短;水乳环氧树脂可以明显提高水硬性凝胶隔段的抗压强度并提高与管壁面的胶结强度,当水乳环氧树脂加量为3%时,120℃养护5 h后,水硬性凝胶隔段抗压强度达到4.61 MPa,与管壁面胶结强度达到1.39 MPa;同时固化隔段自身胶结好,在承压封气装置中突破压力不小于1.02 MPa/m;形成的固化隔段可钻性级值为2级,采用钻头即可快速钻除。水乳环氧树脂与水硬性凝胶工作液结合后的减水作用和固化交联作用,能改善水硬性凝胶固化体的组织结构,减少微观缺陷的产生,同时增强固化体的致密性,阻止了裂缝扩展,改善了凝胶隔段的力学特性。

Aimed at the problem that the formation fluid can not be plugged effectively to prevent the fluid from flowing upward during the process of the precise pressure control drilling due to the lower compressive and cementation strength,much aperture and fracture of the solid packing formed by hydraulici gel,a kind of waterborne epoxy resin CQ-WERE and matched curing agent CU-900 as the properties modification agent(PMA)was added into the hydraulic gel working fluid(HGWF)and the influence of the PMA on the rheology of HGWF and mechanical property of solid packing formed by HGWF was investigated,and the mechanism that the PMA improved the mechanical property of the solid packing was analyzed. The results showed that the PMA had good compatibility with the HGWF,the PMA had less influence on fluidity and rehology property of the HGWF;the thickening time of the HGWF decreased with the PMA dosage increased;the PMA could significantly improve the compressive strength of the solid packing and cementation strength between the solid packing and the pipe surface,with PMA dosage of 3%,after curing at the temperature of 120℃for 5 h,the compressive strength and cementation strength could increased up to 4.61 MPa and 1.39 MPa/m,respectively;meanwhile,the self-cementing ability of the gel packing was good,the air sealing pressure being not less than 1.02 MPa/m;the drillability grade of the solid packing was 2,meaning that the solid packing could be easily drilled out. When the PMA was added to the HGWF,the water-reducing and solidification crosslinking effect was achieved,which could modify the organization structure of the solid packing,decrease the micro-defect,strengthen the compactness,prevent fracture from propagating and improve the mechanical property of solid packing.