川西气田能量补充型泡排技术优化研究

Study on Optimization of Energy-supplemental Foam Drainage Technology in the Western Sichuan Gas Field

川西气田绝大部分低压低产气井采用传统泡排工艺排水,但部分气井由于井型、井身结构、产气量低等原因造成起泡困难,携液效果不理想。能量补充型泡排工艺是向井下注入一种或多种物质发生化学反应生成足够的气体,在井底形成泡沫的新方法。通过开展室内评价实验,优选了自生氮气体系作为反应体系,研制了XH-16A、XH-16B两种新型能量补充型泡排剂,确定了XH-16A与XH-16B药剂的最佳配比为3∶1、XH-16A剂最佳浓度为50%,形成了液液泵注和液固加注两种配套加注工艺。为探索能量补充型泡排技术对川西低压低产气田的适应性,开展了现场试验,结果表明,该技术可有效排除井底积液,溶解部分井筒污物,适用于地层日产水量0-1.2m^3/d、油套压差2-7MPa、日产气量介于0.1×10^4m^3/d和临界携泡流量之间、积液周期〉3d的气井;现场应用36井次,累计增产71.69×10^4m^3。

The traditional foam drainage technology was applied to the most of the gas wells with low pres-sure and low production in the western Sichuan gas field,but drainage effect was not ideal in some of the gas wells for being hard to be foamed because of type,structure and low gas production of the wells.Energysupplemental foam drainage technology is a new method of foam generation at the bottom of the well through gas generation enough for chemical reactions by the injection of one or several matters.Through the laboratory evaluation experiment,the autogenic nitrogen system was selected as the reaction system,and two new energysupplemental foam drainage agents XH-16 A and XH-16 B were developed.The best mixture ratio between XH-16 A and XH-16 B was determined as 3 ∶1,and the best concentration of XH-16 A was determined as50%.Liquid-liquid injection and liquid-solid injection were formed as the matched injection technologies.In order to explore the adaptability of this technology to the low-pressure and low-production gas fields in the Western Sichuan,field tests were carried out.The results show that the technology is suitable for the gas wells with 0-1.2 m^3/d of daily water production,2-7 MPa of pressure difference between tubing and casing,0.1×10^4 m^3/d to the critical carrying capacity of daily gas production,and more than 3 d of liquid loading period,which can effectively eliminate bottom hole fluid and dissolve part of wellbore dirt.It was applied for 36 well-times in the field and cumulative incremental gas production was 71.69 ×10^4 m^3.