为有效封堵出水点明确的高含水水平井,特别是筛管完井水平井,借鉴水坝裂缝处理和防水工程中的堵漏方法,提出了基于小剂量改性氰凝的水平井定点堵水技术.通过对浆液黏度、发泡反应进行化学改性,研制了化学自膨胀-改性氰凝,使其可注入和反应时间可控,并考察了固化体的抗压强度、耐压性及其影响因素;同时,研发了配套的活塞推进输送和架桥驻留工艺.试验得出,研制的化学自膨胀-改性氰凝可在20~90 ℃下延迟可控反应,抗压强度12 M Pa以上,耐压达到20 M Pa.该技术在3口井进行了现场试验,在国内首次实现了L形筛管完井水平井定点堵水.研究结果表明,基于改性氰凝的水平井定点堵水技术可解决水平井长井段定点堵水难题,为治理水平井出水提供了新的技术手段.%In order to conduct water shutoff effectively in high water cut horizontal wells with known water points,especially for wells completed with screens,the fixed-point water shutoff technology for hori-zontal wells with low-dose modified cyanogen coagulation was proposed by drawing on the experience of leakage prevention in dam crack treatment and waterproofing engineering.Through the chemical modifica-tion of viscosity and foaming reaction of the slurry,a modified chemical self-swelling cyanogen coagulation was developed,so as to make it injectable and obtain a controllable reaction time.The compressive strength,pressure resistance and influencing factors of the solidified body were investigated;meanwhile,the matched piston forwarding and bridging residence process were developed.Test results demonstrated that the modified self-swelling cyanogen coagulation as a plugging agent could delay the controllable reaction at 20-90 ℃,its compressive strength is over 12 M Pa,and its pressure resistance is up to 20 M Pa.Field tests were conducted in 3 wells,including the first fixed-point water shutoff in horizontal well completed with L-type screen pipe in China.The results demonstrated that the fixed-point water shutoff technology based on modified cyanogen coagulation in horizontal wells could solve the fixed-point plugging problems in extend-ed reach horizontal wells.They could also provide new technical means for water producing treatment in horizontal wells.
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