采卤老腔改建盐穴储气库关键技术及应用

Key Technology and Application of Reconstruction of Existing Brine Extraction Caverns into Salt Cavern Gas Storage

为利用对流井采卤老腔改建地下储气库,总结已有采卤老腔改建盐穴储气库的经验,分析其在对流井采卤老腔改建储气库中的适用性,确定了更为准确的改建基本条件、密封性测试压力计算公式,给出合格评价条件、稳定性分析中数值模拟方法的改进测试方式、井筒改造新工艺以及作业技术要求。将研究成果应用于淮安地区的老腔改建,选取的对流井符合改建条件;密封性测试中注水升压10次,注水井压力变化为3.258~3.478 MPa,井口压力和漏失量下降幅度明显变小,满足储气条件;确定采用封堵老井、另钻一口新井的施工方案,生产套管尺寸为Φ244.5 mm;采用气库运行上限压力1.1倍的压力进行了试压。研究成果对中国盐矿中大量对流井采卤老腔改建工程具有指导意义。

In order to reconstruct the existing brine extraction caverns in convection well into underground gas storage,the experience of the reconstruction of existing brine extraction caverns into salt-cavern gas storage was summarized,its applicability in the reconstruction of brine extraction caverns in convection well into gas storage was analyzed,the more accurate basic conditions and the calculation formula of sealing test pressure were determined for reconstruction,and the qualification evaluation conditions,the improved test method for numerical simulation method in stability analysis,the new technology for wellbore reconstruction and the technical requirements of the operation were given.The study results were applied to the reconstruction of the old caverns in Huaian Area,and the selected convection well met the reconstruction conditions;the pressure change in the injection well was 3.258 to 3.478 MPa during the sealing test with 10 injection pressure ramps,and the wellhead pressure and leakage decreased significantly,satisfying the gas storage conditions;the construction plan of sealing the old well and drilling another new well was determined,and the production casing size was 244.5 mm;a pressure test was conducted at a pressure 1.1 times the upper limit of operating pressure of the gas storage.The results of the study are of guidance to the reconstruction of a large number of existing brine extraction caverns of convection wells in domestic salt mines.