川西气田低压低产井净化与排液联合作业技术

Combined operation technology of purification and drainage for low pressure and low production wells in West Sichuan gasfield

针对川西气田低压低产井长期注入起泡剂,造成井底污染和排液双重难题,研制了井底净化药剂,实验表明驱替致密砂岩天然裂缝岩心后,渗透率提高44%,启动压力降低了11%,净化效果明显。配套了“小液量泵注+措施排液+多次净化”一体化作业技术,现场应用10口井,措施有效率达到80%,单井平均产量上涨49%,措施有效期达到138 d,累计增产天然气59×104m3,经济效益显著,为同类气井治理提供了借鉴意义。

In order to solve the double problems of bottom hole pollution and drainage caused by long-term injection of foaming agent into low-pressure and low production wells in Western Sichuan gasfield,a bottom hole cleaning agent was developed.The experiment shows that after displacing natural fractured cores in tight sandstone,the permeability increases by 44%,the starting pressure decreases by 11%,and the cleaning effect is obvious.Viscous and inorganic scales are the main purification agents,and the bottom hole purification process of"small liquid volume+multiple purification+measures drainage"is formed.10 wells are applied on site,the effective rate of measures reaches 80%,and the average output of single wells rises 49%,the effective period of the measure reached 138 d,and the purification effect at the bottom of the well was obvious,which provided reference for the similar gas well treatment.