油田废弃井改造成地热井的水层酸洗方案研究

油田废弃井改造是实现二次开发、重复利用资源的有效方式。东濮106井为中原油田废弃井,经过对目的层(即奥陶系碳酸盐岩热储层)以酸洗方式进行酸化改造,现已改造为地热井。经过多次配伍实验,酸液体系选择缓速有机酸系列(15%HAc),该酸液具有反应速度慢、作用距离大、二次伤害低等优点;缓蚀剂浓度选定为0.5%;最终表面活性剂采用FC-01和ABS。选取15%HAc与0.5%缓蚀剂(B溶剂),并相应添加粘土稳定剂、表面活性剂和铁离子稳定剂等药品。该研究验证了改造方案和技术的可行性,并为今后废弃井改造酸洗液的选择提供了新思路。

Scheme of acid washing to heat reservoirs in geothermal wells reconstructed from abandoned wells in oilfields

Reconstruction of abandoned oil wells is an effective way to realize secondary development and reuse resources. The well Dongpu106 is an abandoned oilfield well and has been transformed into a geothermal well by acid washing to the target layer, the Ordovician carbonate heat reservoir. The scheme of this acid washing is as follows. After many times of compatibility experiments, the acid solution system selects a slow organic acid series (15% HAc), which has the advantages of slow reaction, large action distance, and low secondary damage. The concentration of the corrosion inhibitor is 0.5%. The agent uses FC-01 and ABS. The final formula is 15% HAc + 0.5% corrosion inhibitor B + clay stabilizer + surfactant + iron ion stabilizer. Tests have verified the feasibility of this scheme. It provides a new idea for selecting the proper acid washing liquid to reform abandoned wells.