金坛盐穴储气库畸形对盐腔体积影响

Distortion Influence on Cavern Volume of Jintan Salt Cavern Gas Storage

王建夫 巴金红 王文权

WANGJianfu BAJinhong WANGWenquan

中国石油储气库分公司, 北京 昌平 100029 中国石油盐穴储气库技术研究中心, 江苏 镇江 212000

PetroChina Gas Storage Company, Changping, Beijing 100029, China PetroChina Research Center of Salt-cavern UGS Technology, Jiangsu, Zhenjiang 212000, China

金坛盐穴储气库属于层状盐岩型储气库，建设过程中经常出现腔体畸形、偏溶现象，严重降低盐腔有效体积。研究腔体畸形对盐腔体积的影响规律，并在造腔过程中加以控制，将有助于加快库容工作气形成。结合金坛盐穴储气库实际盐腔情况，分析了腔体畸形、偏溶和底坑形状对盐腔有效体积的影响，并根据其形成原因给出了相应解决措施。结果表明，金坛盐穴储气库畸形、偏溶腔体约占总数的30%，畸形系数（11.8~90.1）×10，畸形系数越大盐层利用率越低；畸形导致横截面为椭圆形，且不同深度的腔体直径差别较大，使腔体周围盐层利用率降低；偏溶使井间矿柱宽度过低，矿柱比减小，腔体直径受限，腔体积严重降低；底坑形状可分为“V”形、“一”形、“\”形、“A”形4种，其注气排卤效率依次降低，其中，“\”形、“A”形最不利盐腔空间利用，严重降低储气体积。对于腔体畸形可采用的控制手段有降低排量、采用正循环、天然气阻溶回溶等技术。对于偏溶可采用预测偏溶方向合理设计井位、降低矿柱比增加腔体直径等措施。底坑畸形尚无有效控制手段和提高注气排卤措施。该研究为后期腔体形状控制和提高盐腔体积奠定了理论基础，将有助于加快金坛盐穴储气库建设速度。

Jintan salt cavern gas storage is constructed in layered salt rock. In the construction, the cavern distortion and leaching often occur, which seriously reduce the effective volume of salt cavern. It is helpful to increase the gas storage capacity by studying its influence on the cavern volume and controlling the leaching method. Based on the actual condition of Jintan salt cavern gas storage, the influence of cavern distortion, partial leaching and sump shape on the effective volume was analyzed. The results show that the distorted and partially-leaching caverns account for about 30% of the total number, the distortion coefficient ranges between (11.8~90.1)×10, and the larger the distortion coefficient, the lower the utilization rate of salt layer; the cross-section of salt cavern is elliptical, and the diameter of cavern varies greatly with different depth, which reduces the utilization rate of salt layer around the cavern; partial leaching reduces the pillar width between adjacent caverns as well as the ratio, so the diameter of cavern is limited, and the cavern volume is seriously reduced; the sump can be divided into "V", "-", " \" and "A" shapes, and the brine discharge efficiency decreases in turn. The last two kinds are the most unfavorable for cavern space utilization and seriously reduce gas storage volume. For the cavern distoration, the means includes reducing the displacement, using positive circulation, natural gas dissolution inhibition technology. For partial leaching, measures such as predicting the direction of partial leaching and reasonably designed well location, reducing P/D and increasing the diameter of cavern can be adopted. There are no effective measures to control the sump deformity and improve the brine discharge efficiency. The research gives a theoretical foundation for the cavern shape control and the improvement of cavern volume, which is helpful to the construction of Jintan salt cavern gas storage.

10.11885/j.issn.1674-5086.2020.10.09.02