煤层气井分散防固结-定期洗井工艺

Dispersing consolidation prevention and periodic well cleaning technology for coalbed methane wells

罗凯 刘源 朱延茗 赵丹 尹海亮 刘新亮

LUO Kai LIU Yuan ZHU Yanming ZHAO Dan YIN Hailiang LIU Xinliang

中国石油浙江油田分公司 中国石油大学(华东)

PetroChina Zhejiang Oilfield Branch, Hangzhou 645250, Zhejiang, China China University of Petroleum (East China), Qingdao 266000, Shandong, China

针对蜀南煤层气田井筒存在铁盐-煤泥复合垢的问题，开展了室内实验和现场工程相结合的防垢技术研究。通过建立室内实验评价方法，完成了3种有机膦酸和2种聚合物类药剂对煤粉颗粒物的分散性实验和防煤泥固结实验。通过动态光散射及表面Zeta电位测试，分析了药剂对颗粒物粒径分布、Zeta电位的影响，以及影响药剂对煤粉颗粒物分散和防煤泥固结效果的原因。研究结果表明，有机膦酸类药剂中乙二胺四亚甲基膦酸(EDTMPS)分散性较好，但受高铁盐的影响，防煤泥固结能力较差，不适合本区的结垢防治，而聚合物类药剂更适用于此类复杂水质下的结垢防治。根据药剂特性，在现场施工中实施了分散防固结-定期洗井组合工艺，该方案开展3年以来区块煤层气井结垢速率显著下降，检泵周期延长至1.3~3倍，取得了良好的应用效果。

In the coalbed methane fields in southern Sichuan, aiming at the problem of composite scale caused by ferric salt and coal slime in the wellbore, researches on anti-scaling technology combining laboratory experiments and field engineering were carried out. The method for evaluating indoor experiment was established, and the experiment dispersing coal powder particles and the experiment preventing coal slime from consolidation were completed with 3 kinds of organic phosphonic acids and 2 kinds of polymer agents. The influence of chemical agents on particle size distribution and Zeta potential was investigated by dynamic light scattering and surface Zeta potential testing, and reasons influencing the effects of chemical agents on the dispersion of coal particles and the consolidation prevention of coal slime were preliminarily analyzed. The research results show that the ethylenediamine tetramethylenephosphonic acid (EDTMPS) in the organic phosphonic acids is of good dispersibility, however, due to the influence of high ferric salts, the coal slime consolidation prevention ability of the EDTMPS is poor, which is not suitable for scaling prevention in this area. Nevertheless, polymer agents are more suitable for scaling prevention and control under such complex water quality. According to the characteristics of the agents, the combined process of dispersing consolidation prevention and periodic well cleaning was implemented in the field construction. The scaling rate of coalbed methane wells in the block has been significantly reduced since the program was launched 3 years ago, and the pump inspection period was extended to 1.3 to 3 times, achieving perfect application effect.

10.13639/j.odpt.2022.01.012