胜利油气区浅层气藏的开采规律研究

A STUDY ON THE PRODUCTION RULE OF THE SHALLOW GAS RESERVOIRS IN SHENGLI OIL AND GAS REGION

胜利油气区的浅层气藏主要分布于第三系馆陶组、明化镇组及第四系平原组。气藏类型主要为透镜状岩性气藏，少量为构造—岩性气藏。由于气层埋藏浅、成岩性差、胶结疏松，以及大部分气砂体存在边底水，存在气井易出水、出砂、稳产期短等开发特征。经过２０余年的开发实践认识到：①稳定、合理的工作制度是延长气井自喷期的基础；②新井先期防砂是延长气砂体生命期的必要保证；③自下而上逐层上返的分层开采是浅层气藏生产的基本原则；④合理的射开程度是延长边底水气井无水采气期的先决条件；⑤降低井口回压，排水采气是增加气砂体可采储量的有效途径。

The shallow gas reservoirs in Shengli oil and gas region are mainly distributed in the Guantao Formation and Minghua Formation of the Tertiary and the Pingyuan Formation of the Quaternary. Gas reservoir types are mainly the lenticular lithological reservoirs,the structural lithological reservoirs being in the minority.Owing to the fact that the gas formations are shallowly buried,being of early diagenesis and loose cementation,as well as most of the gas bearing sand bodies have edge/botom water,the gas wells are possessed of the development characteristics of being easy to be watered and sanded,and being of a short stable production period.Through the development practice for more than twenty years it is thought that a stable and reasonable working system is the basis of prolonging the flowing period of gas well;the initial sand control in a new well is the necessary guarantee for prolonging the life period of gas bearing sand body;the successive separate layer recovery from down to up is the basic principle of exploiting the shallow gas reservoir;a reasonable perforation density is the prerequisite to prolonging the water free gas production period of the gas well with edge/bottom water;and decreasing wellhead back pressure and drainage gas recovery are the effective ways for increasing the gas bearing sand body's recoverable reserves.