油气藏型储气库地质体完整性内涵与评价技术

Connotation and evaluation technique of geological integrity of UGSs in oil-gas fields

地下储气库(以下简称储气库)全生命周期完整性管理已成为其长期安全有效运行的重要保障,目前我国油气藏型储气库完整性及其评价技术以地面设施和注采井为主,地质完整性评价对象与概念不明确且缺乏系统的评价技术。为此,在总结相关研究成果的基础上,提出了以储气地质体为评价对象的地质体完整性概念,建立了油气藏型储气库地质体完整性评价技术体系,并以新疆呼图壁储气库为实例开展了储气库地质体完整性评价。研究结果表明:①储气库地质体完整性是指在储气库运行过程中,储气地质体各组成部分能够满足运行要求、安全经济地完成季节与应急调峰任务的各项性能指标的完整程度,其内涵是在储气库运行生命周期内,地质体的储层以及盖层、断层和圈闭可以为用户持续稳定提供气量,并保证储气库安全运行,其核心是在储气库运行生命周期内保持天然气存储的可靠性、安全性和经济性的程度;②地质体完整性评价技术体系由圈闭有效性、盖层完整性、断层稳定性、储层稳定性4项评价技术构成;③评价结果显示,呼图壁储气库具有提高上限压力扩大调峰气量的潜力。结论认为,油气藏型储气库地质体完整性评价技术体系的建立,健全了储气库完整性评价技术系列,对油气藏型储气库长期安全有效运行、提高运行上限压力、增强调峰能力等具有指导作用和应用价值。

Whole-life-cycle integrity management of underground gas storages(UGSs)has been an important link to ensure its long-term safe and efficient operation.At present,the integrity of UGSs in oil-gas fields and its evaluation techniques focus on surface facilities and injection/production wells,but its geological integrity lacks clear definition and evaluation object and systematic evaluation techniques.In this paper,relevant research achievements were firstly summarized.Then,the concept of geological integrity with the gas-storage geological body as the evaluation object was put forward,and the evaluation system for the geological integrity of such UGSs was established.Finally,UGS geological integrity evaluation was carried out with the Hutubi Underground Gas Storage in Xinjiang as an example.And the following research results were obtained.First,UGS geological integrity is defined as the integrity degree of each component of a gas-storage geological body to meet operation requirements and fulfill seasonal and emergency peak shaving safely and economically during the operation of a UGS.Its connotation is that reservoir of geological body,caprock,fault and trap can supply the customers with gas continuously and stably and ensure the safe operation of the UGS in its service life.And its core lies in keeping the reliability,safety and economy of natural gas storage in the service life of a UGS.Second,the geological integrity evaluation system is composed of four evaluation techniques,including trap effectiveness,caprock integrity,fault stability and reservoir stability.Third,the evaluation results show that the Hutubi Underground Gas Storage has the potential of peak-shaving capacity enhancement by increasing the maximum operation pressure.In conclusion,the establishment of the geological integrity evaluation system for such UGSs improves the UGS integrity evaluation technology system and plays an instructive and practical role in ensuring the long-term safe and efficient operation of UGSs,increasing the maximum operation pressure and improving the peak shaving capacity.