自生气发泡液体系研究与应用

A Self-Foaming Solution for Bottom Liquid Removal in Gas Wells

本文报道可用于排除产气量不足或严重水淹气井井底积液的自动发泡体系及其应用结果。该体系由加入催化剂、总浓度为2 mol/L的NH4Cl+NaNO2自生气反应溶液及起泡剂、稳泡剂组成。在温度30℃、pH=3条件下,通过产气量测定选择乙酸为催化剂。推荐采用文献发表的该体系反应动力学方程,由所需产气速度、井底温度计算催化剂用量(体系pH值)。在发泡实验中,在转速1000 r/min下测定50 mL自生气反应溶液30℃、搅拌60 min产生的泡沫量、携液量、泡沫泄液半衰期及半衰期泡沫量(大于初始泡沫量)。通过发泡实验选择工业品十二烷基硫酸钠为起泡剂,用量0.8%,羟丙基瓜尔胶为稳泡剂,用量0.6%。在井深2980 m,井底温度大于65℃、水淹严重、已基本停产的川中磨144气井,通过套管注入该自动发泡液29 m3,排出井底积液84 m3,气井恢复生产,产气量为5.2×104m3/d。图1表2参5。

An self-foaming solution for removing bottom liquid in poor or watered out natural gas wells and its use are presented. This solution is a gas-generating chemieal solution of 1 mol/L NH4Cl and 1 mol/L NaNO2 with a catalyst, a foamer, and a foam stabilizer added. Acetic acid is selected as catalyst through gas generation measuring at 30℃ and pH = 3. A chemical kinetic equation for the gas-generating system published else while is recommended for calculating the catalyst, or pH value, need when the gas-generating rote and the bottom tomperature are given. In foaming tests, the volume of foam formed from 50 mL gas-generating foaming solution at 30℃ after 60 min stirring at 1000 r/min, the volume of solution foamed, the half-life time, t1/2, of foam, and the volume of foam at t 1/2 （which is always larger than initial foam volume） are taken as characteristics of foaming capability of the test solution. Through foaming tests, a commercial dodecyl sulfate is chosen as foamer at dosage 0.8% and hydropropyl guar gum-as foam stabilizer at dosage 0.6%. Gas producing well M-144 in central Sichuan district of 2980 m deep and bottom temperature 〉65℃ was watered out and practically ceased to producing gas; 29 ms of gas-generating foaming solution was injected into the well through the annular space and in result totally 84 ms accumulated at the well bottom liquid war flown out of the well. After this job finished, this restarted gas production in a rate of 52000 m^3/d.