用渗流机理物理模拟技术研究气田出水机理——以涩北气田为例

Application of physical simulation of seepage mechanism to the study of reasons of water breakthrough in gas wells:A case study of the Sebei gas field

出水是制约涩北气田稳产及降低气田开采效益的主要因素,对出水机理的深入、全面认识,是涩北气田找水、防水和治水措施成功的前提,更是涩北气田产能建设及稳产目标实现的重要保障。涩北气田属于多层疏松砂岩的出水气藏,开采难度大,不确定性因素多,国内外相似气田的开发理论和开发经验都很缺乏。目前对其储层内气水渗流机理和出水机理的认识大部分仍然只是定性的,缺乏量化分析,无法对防水治水措施的制定提供操作性强的指导,迫切需要全面深化对疏松砂岩储层渗流机理的物理模拟研究。通过调研国内外在疏松砂岩岩心加工、储层物性参数测试的校正、渗流机理的微观物理模拟等方面的技术进展,结合气田储层物性特征、气水两相的渗流特征以及目前对气田出水规律的认识,探讨了气田出水机理物理模拟的实验技术思路,为下一步室内实验装置与实验方案的设计奠定了理论基础。

Water breahthrough is a main factor restricting steady gas production and decreasing gas recovery to a large degree in the Sebei gas field.To have a full knowledge of this mechanism is not only a precondition of prediction,prevention and control of water production,but also a guarantee for the stable production and productivity construction in the Sebei gas field.The Sebei gas field is characterized by multilayer loose sandstone gas reservoirs and water breakthrough so its development is of great difficulty with many uncertainties in addition to the lack of theory and experience from developing other similar gas fields at home and abroad.At present our knowledge on the mechanism of both gas/water seepage and water breakthrough in gas layers is based on qualitative analysis instead of quantitative one so we can not take any feasible measures to prevent or control water production,and that is why we conducted deep investigation into physical simulation on seepage mechanism in loose sandstone gas reservoirs.Through a survey on the global technical progress of loose sandstone core process,geophysical parameters test calibration,and microcosmic physical simulation of seepage mechanism,and so on,we combined with geophysical features of gas reservoirs,seepage characteristics of gas/water phases,and the present knowledge of water breakthrough discipline to fully discuss on the laboratory technology of physical simulation of water breakthrough mechanism,thus providing robust theoretical foundation for further indoor experimental facility and program design.