含夹层盐岩孔隙特征及非线性渗透模型

Pore characteristics and nonlinear permeability model of salt rocks with interlayers

为了有效识别腔体之间以及腔体与断层之间的封闭性、安全性,有必要对盐穴储气库中夹层及盐岩的密闭性及渗透特征进行研究,识别腔体间或腔体与断层间存在的渗漏风险。结合金坛地区的地质情况,分析夹层及盐层孔隙结构,建立气体渗透非线性渗流模型,考虑了气固分子作用力及扩散作用对渗流的影响,基于此模型对金坛储气库两口相邻腔体矿柱存在夹层情况下的密闭性进行分析,并对腔体周边存在断层的情况进行研究。盐岩有很好的密闭作用,是非常好的储库建址选择,但泥岩夹层中气体的渗透性明显。因此,对含夹层盐层进行建腔,确定腔体之间、腔体与断层之间距离具有重要意义。(图9,表1,参24)

In order to identify the sealing capacity and safety between cavities or between cavity and fault, it is necessary to study the sealing capacity and permeability of the interlayers and salt rocks of salt cavern gas storages, and to identify the risk of seepage between cavities or between cavity and fault. In this paper, the pore structures of interlayers and salt rocks were analyzed based on the geological conditions in Jintan area. Then the nonlinear seepage model of gas permeability was established, and it considers the effects of gas-solid molecular force and diffusion on gas seepage. Finally, this model was applied in Jintan Gas Storage to analyze the sealing capacity between adjacent cavities with interlayers in pillars, and investigate the situations of the faults around the cavities. Salt rocks are very good choice for the site of underground gas storage due to its good sealing capacity, but the gas permeability of mudstone interlayers is relatively obvious. So it is of great significance to the solution mining of salt rocks with interlayers and the optimization and determination of the distance between the cavities or between cavity and fault. （9 Figures, 1 Table, 24 References）