充气泡沫酸解堵技术在低压气井增产中的应用

Plugging removement technology of aerated foamed acid and its application in low-pressure gas well

针对气藏开发中后期气层污染堵塞特点,研究出一套适应低压气藏解堵的工艺措施——充气泡沫酸解堵技术。该泡沫酸酸液体系耐高温、耐高矿化度、耐油性能好,开发出的泡沫发生器发泡性能好,在高温高压下能形成性能稳定的均匀泡沫流体。充气泡沫酸具有缓速酸溶、增能、高分散、分流、低密度、易返排、携带能力强的特性,有效解决了低压低能气井(层)酸化效果差的问题。在施工工艺上改进了以往解堵措施先将井筒灌满,液体漏失造成储层永久伤害的问题,先往地层注气,形成近井地带暂时高压,同时利用泡沫分流特性,提高低渗层段酸化改造生产能力,最后气氮将残液及反应后残渣带出。整个施工过程不打水,做到少进液、深穿透、二次伤害低。截至目前,泡沫酸解堵技术在文23气田现场施工应用18井次,工艺成功率100%,施工井有效率92.0%以上,累计增气2 069×104 m3,取得了显著的增气效果。现场试验表明,泡沫酸解堵技术是解除气井储层伤害和残液返排行之有效的工艺措施,对低压低能气层解堵有较强优势,填补了低压气井解堵增产中的一项空白,具有很高的推广应用价值,为同类油田油气井治理提供了借鉴。

In order to remove the formation plugging of gas reservoir at the intermediary and later stages of gas reservoir development,a set of plugging removement technologies of aerated foamed acid,which is suitable for the plugging removement of low pressure gas reservoir,is developed.This aerated foamed acid system is characterized by high temperature resistance,high salinity resistance and good oil resistance.The developed foam generator has a good foam generating capacity,it can generate the stable and homogenous foam fluid at high temperature and pressure.This foam fluid has better operating capacity,such as retarded acid etching,energy generation,high breakup,divided flow,low density,easy flowback and good carrying capability.It can improve the poor acidification effect in low-pressure and low-energy gas wells.The previous questions of which the wellbore was filled with first step in the past and the liquid leakage caused the permanent reservoir damage have been improved in the operation process.At first,the gas is injected into the formation,forming a temporary high-pressure zone near the borehole,while taking advantage of the foam streaming features to improve the production capacity of low permeability reservoir during acidification treatment.Finally the reaction residue will be carried out by nitrogen gas.Water is not fetched throughout the construction process,with less liquid entering,deep penetration and low secondary damage.Up to now,this plugging removement technology has been tested in 18 wells.The field operation success ratio is 100%,effective ratio of treated well is 92%.Cumulative gas increase is 20.69 million cubic meters,and gas production increasement is obvious.The plugging removement technology is an effective stimulation treatment for removing the reservoir damage of gas well and residual liquid flowback in low pressure and low productivity gas well,and it fills a blank space in the plugging removement and stimulation treatment of low pressure gas well.It has a high popularization value and provides a reference for the oil-gas well controlling of similar oilfields.