盐穴储气库水溶造腔巨厚隔层失稳机理与垮塌控制

The deep salt mine deposits in China are divided into several mined beds. So, it is a significant scientific and technological challenge of solution mining for gas storage that how to promote the connection of two adjacent thick mined beds. Researches on the mechanism of instability and collapse of the thick insoluble interbed will be carried out in this project, of which the main contents include: taking Jianghan and Huaian natural gas storages as supported projects, high temperature and high pressure experiments of typical spamles of thick insoluble interbed under brine erosion will be carried out, then the laws of mechanical property weakening will be indicated; the evaluation model of damage of thick insoluble interbed under coupling of brine erosion, rock mass fracture and high pressure brine seepage will be established; based on the model, the instability modes and criterions of different types of thick insoluble interbeds will be studied, in turn, dynamic forecasting model of the instability of thick insoluble interbed will be proposed; the determination methods of solution mining parameters of accelerating interbed collapse and correction time of asymmetrical collapse will be studied, then the theories will be modified by cases of the supported projects, further, the theories and methods of controlling collapse of thick insoluble interbed will be proposed. The research results will provide theoretical support for design and construction of solution mining for gas storage in salt mine with thick insoluble interbed. And the research results will help to enlarge cavern volume and reduce solution mining risks.

我国湖相沉积形成的深部盐岩矿床，往往被巨厚隔层分割为若干开采层,如何安全有效地处置难溶难垮的厚隔层，使厚隔层上下相邻开采层贯通，从而保证足够的建库高度，已成为盐穴储气库水溶造腔的重要工程科技难题。本项目围绕厚隔层失稳垮塌机理这一关键科学问题开展研究，主要研究内容包括：以江汉和淮安储气库的造腔工程为依托，选取典型厚隔层岩心，系统开展高温高压卤水侵蚀试验，研究厚隔层力学特性的弱化机理与规律；建立“卤水溶蚀-岩体破裂-高压卤水渗流”耦合作用下的厚隔层破坏评价模型，基于该模型研究不同类型厚隔层的失稳模式及其判据，并提出厚隔层失稳的动态预测模型；研究促进厚隔层安全垮塌的工艺参数的确定方法，以及厚隔层不均匀垮塌后的修正时机与方法，应用依托工程现场案例检验并修正理论成果，形成调控厚隔层垮塌的理论与方法。研究成果将为含厚隔层盐矿的造腔设计与施工提供理论支撑，有助于保障储气库建库规模并降低造腔施工风险。

我国湖相沉积形成的深部盐岩矿床，往往被巨厚隔层分割为若干开采层，如何安全有效地处置难溶难垮的厚隔层，使厚隔层上下相邻开采层贯通，从而保证足够的建库高度，是盐穴储气库水溶造腔的重要工程科技难题。本项目围绕厚隔层失稳垮塌机理这一关键科学问题开展研究，主要研究内容包括：以江汉储气库的WCH3井造腔工程为依托，选取该储气库的巨厚隔层（12#夹层）岩心，系统开展了造腔环境下卤水侵蚀试验，研究了厚隔层力学特性的弱化机理与规律；建立了“卤水溶蚀-岩体破裂-高压卤水渗流”耦合作用下的厚隔层破坏评价模型，基于该模型研究了厚隔层的失稳模式及其成因，并提出了厚隔层失稳的动态预测方法；研究了促进厚隔层安全垮塌的工艺参数的确定方法，以及厚隔层不均匀垮塌后的修正时机与方法，应用于江汉WCH3井巨厚隔层垮塌控制现场，形成了调控厚隔层垮塌的理论与方法。研究成果为含厚隔层盐矿的造腔设计与施工提供理论支撑，有助于保障储气库建库规模并降低造腔施工风险。