含H_2S生产污水回注井解堵增注剂研究与应用

Study and Application of Agents for Increasing Water Injection in Wells Rejecting Sewage Containing H_2S

针对海上NHX油田3口回注井水质差,注水压力升高、注水量下降的情况,结合地质油藏特征分析其储层伤害原因,构建了复合解堵药剂体系(ZSJ-Y和ZSJ-W)。该药剂体系具有适用性强、腐蚀速率低、铁离子及黏土稳定能力强等特点,室内评价实验表明解堵后岩心渗透率恢复率为102.37%。首次成功应用于NHX-12b井,同等条件下日注水量增加656 m^3,视吸水指数从先前的161.3 m^3/d·MPa提高到232.6 m^3/d·MPa,提高了44.2%,取得了极好的解堵增注效果,具有良好的应用前景,同时也为海上油田类似回注井的解堵增注提供了良好的借鉴。

The quality of sewage water in three reinjection wells of NHX offshore oilfield is poor, resulting in increasing in injection pressure and decreasing in water injection rate. The main reasons for reservoir damage near wellbore area have been analyzed. The compound plugging removal system （ZSJ-Y and ZSJ-W） has been built, which has strong applicability, low corrosion rate, with strong stabilizing capability in ferricion and clay. The results of laboratory evaluation experiment indicated that the core permeability recovery rate after plugging removal was 102.37%. This system has been used successfully in NHX-12b well, with water injection rate increased 656 m^3/d, and the apparent water injectivity index was increased from 161.3 m^3/d·MPa to 232.6 m^3/d·MPa, increased by 44.2%. This system has excellent plugging removal results and injection stimulation effect, and can be used widely. In addition, it provides reference for plugging removal in similar offshore reinjection well.