盐穴储气库小间距双井造腔参数研究

夹层多、盐层薄是我国盐岩赋存的主要特点。目前，我国普遍采用的单井对流法在造腔速度以及夹层控制等方面存在诸多不足。小井间距双井造腔方法采用大尺寸造腔套管对井直流排卤，具有造腔速度快、建库周期短、盐层利用率高等优点。为了探究该方法中关键造腔参数对腔体建造的影响规律，本文开展了多组造腔物理模型试验，探究了不同双井间距、注水流量下盐穴腔体的拓展规律。结果表明过小的井间距难以使腔体在水平方向充分拓展，过大的井间距会使得腔体形态不规则。在低注水流量下，会导致注水端腔体顶面过高影响腔体稳定性；而在高注水流量下，腔体形态更加规则，但是需要消耗较多能源和淡水资源。可以认为井间距会直接影响腔体最终形态，注水流量会影响腔体两侧的平衡性。本文给出了小间距双井溶腔方法中双井间距、注水流量等关键造腔参数的选取方法，可以为工程应用提供参考。

Research of parameter selection for cavity construction of small-spaced double wells in gas storage salt cavern

In China, the main characteristics of salt rock occurrence are multiple interlayers and thin salt layers. At present, the single well convection method commonly used in China has many shortcomings in terms of cavity creation speed and interlayer control. The small-spaced double wells method adopts the large-sized casing to discharge brine, which has the advantages of fast debrine speed, short reservoir construction period, and high utilization rate of salt layer. To explore the influence law of the key cavity building parameters on the cavity construction in this method, several sets of physical model tests for cavity building were carried out in this paper, and the expansion law of the salt cavern cavity under different double well spacing and water injection flow rate was explored. The results show that it is difficult to fully expand the cavity in the horizontal direction if the well spacing is too small, and the cavity shape will be irregular if the well spacing is too large. Under low water injection flow, the top surface of the cavity at the injection end will be too high, which will affect the stability of the cavity; while at high water injection flow, the cavity shape is more regular, but more energy and freshwater resources are consumed. It can be considered that the well spacing will directly affect the final shape of the cavity, and the water injection flow will affect the balance on both sides of the cavity. This paper presents a method for selecting key cavity-forming parameters such as the double-well spacing and water injection flow rate in the small-spacing double-well dissolution cavity method, which can provide a reference for engineering applications.