大池干井气田石炭系气藏水侵早期治理现场试验及成效分析

ON-THE-SPOT TESTING AND RESULT ANALYSIS OF EARLY REGULATING WATER INVASIONS IN CARBONIFEROUS GAS RESERVOIRS IN DACHIGANJING FIELD

大池干井气田是川东高陡构造带东部的一个大型整装气田 ,由多个高点和多个气藏组成 ,在开发中均产生气藏局部水侵 ,严重地影响了气田生产规模和高效开发。在对气藏早期水侵机理及地质特征深入研究和论证的基础上 ,提出了大池干井气田石炭系气藏各高点水侵早期整体综合治理最优方案 :即龙头—吊钟坝高点是池2 7井水区机抽排水泄压提高池 39井产能、池 1井地层水回注及池 34井控水采气和地层水处理后就地排放的方案 ;万顺场高点是池 6井带水采气、池 2 4井地层水回注的方案 ;磨盘场高点是池 6 1井酸化解堵提高产量后气水同产并用同井场池 38井回注地层水的方案。通过实施和现场生产试验 ,在一定程度上达到了抑制水侵进一步恶化的目的 ,使出水气井的产能有较大提高 ,稳住了气藏开采规模 ,保护了资源和环境 ,经济效益显著。通过试验 ,也形成了一套比较成熟的水侵综合治理技术 ,对其它类似气田的水侵治理具有先导作用。

Dachiganjing gas field is a large-sized integral gas field in the eastern part of the high and steep structural belt in East Sichuan and it is composed of several highs and gas reservoirs. In gas field development, local water invasions have been formed in all of the reservoirs, which seriously influences the gas field production scale and development effectiveness. On the basis of deep-going research on the early water invasion mechanism and geological characteristics of the gas reservoirs, several optimal plans Of early and comprehensively regulating the water invasions at various highs of Carboniferous gas reservoirs in Dachiganjing field were put forward by the authors, i. e. the plan of the relief formation pressure by mechanical drainage in the water invasion area of well Chi - 27 to raise the productivity of well Chi - 39, the formation water reinjection in well Chi - 1 and the drainage-controlling gas recovery in well Chi 34 and the on-site emission of formation water after treating was adopted for Longtou-Diaozhongba high; the plan of water-carrying gas recovery in well Chi - 6 and formation water reinjection in well Chi - 24 for Wanchunehang high; and the plan of concurrent production of gas and water in well Chi - 61 after damage removal by acidizing and formation water reinjection in well Chi - 38 at the same well-site for Mopanchang high. Through implementing and on-the-spot production testing, the target for restraining water invasion to a certain extent has been obtained, which causes the gas welt deliverability to be greatly raised, the gas reservoir production scale to be maintained, the resources and environment to be protected and a large economic efficiency to be achieved. Based on this, a set of relatively mature techniques of comprehensively regulating water invation has been formed, which is of guiding significance for regulating water invasion in other similar gas fields.