关键词: 页岩气, 平桥南区, 泡沫排水采气, 起泡剂, 间歇泡排制度

Abstract:

Foam drainage-gas recovery technology is the most common nowadays and is the most effective application technique. However, due to the certain difference in production conditions of different gas fields, the mode, type, and foam drainage system of foaming agents are different. At present, southern Pingqiao adopts the method of 24 h continuous injection which is commonly used in other gas fields. It works in some wells, but for other wells, this technology dose not works well. In order to form a set of foam drainage model suitable for shale gas wells in southern Pingqiao, combined with laboratory evaluation, field test and economic evaluation, it is proved that the foam drainage process can effectively carry out the bottom hole liquid accumulation and achieve a certain degree of production increase. But in the later stage, it is more focused on reducing the production decline of shale gas wells and ensuring the stable production of gas wells. The XHY-4M type liquid foaming agent is optimized for foaming. When the concentration of defoamer is 0.3 %, the concentration of defoamer is 5 % ~ 20 %, the ratio of defoamer and foaming dose is 1.2∶1, the ratio of water to gas in the well is greater than 0.5, and the overall foam drainage effect is better. Meanwhile, the foam drainage system is constantly adjusted and optimized, and the intermittent foam drainage system of “less injection and multiple times” is adopted, which is more applicable and the effect of economic evaluation is optimal. The results of this study have certain reference for the stable production of similar shale gas wells.

Key words: shale gas, southern Pingqiao, foam drainage-gas recovery technology, foaming agent, intermittence foam drainage system