徐深气田火山岩气藏气井产能的影响因素

松辽盆地徐深气田火山岩气藏的许多开发规律还有待探索，已经试采的井表明火山岩气藏的气井产能特征复杂，搞清其主要影响因素是成功开发该气田的关键。利用地质、试采、试井及室内岩心实验等资料，从宏观与微观两个方面对火山岩气藏气井产能的影响因素进行了研究。得出以下认识和结论：宏观上，火山机构的分布范围、构造位置及储层类型对气井的产能有控制作用，火山岩相具有规模小、多变化的特点使得相邻气井产能变化大、可对比性差；微观上，受到井控可流动区域形态、规模、物性的影响，较窄的流动区域加上较低的地层系数，使得许多井采气指数下降较快，而气井的表皮系数、特殊的渗流特性（启动压力梯度和压力敏感性）、出地层水等都不同程度地影响了气井的产能。此外生产测试中存在的各种情况（如压裂液返排、气井清井期、测试时间等）也可导致对产能认识的偏差。

The influencing factors of gas well productivity for volcanic gas reservoirs in Xushen gas field

Many development laws of volcanic gas reservoirs in the Xushen gas field, Songliao Basin, need further studies, and the production test wells showed complex characteristics of gas well productivity in volcanic gas reservoirs, hence, a better understanding of the main influencing factors of gas well productivity is the key issue for the successful development of this gas field. Therefore, we have done researches on the influencing factors from the macro and the micro aspects by adopting the data of geology, production testing, well testing and indoor core experiments. From a point of macroscopic view, the distribution range, structural locations and reservoir types of volcanic framc play roles on controlling the gas well productivity; the characteristics of small scale and multiple changes of volcanic facies result in a large variation in productivity and poor contrast between offset wells. From a point of microscopic view, the pattern, scale and petro physical properties of the flowing area between the bottom hole and the formation have the effect on the gas well productivity, so the narrower flowing area and the lower formation coefficient make many wells' gas productivity decline rapidly; furthermore, the skin coefficient, special seepage characteristics (starting pressure gradient and stress sensitivity), and water breakthrough in gas wells influence the gas well productivity in various degrees. Besides, any possible accidents existing in production tests, such as fracturing fluid backflow, gas well cleanout period and testing time, may also lead to deviations on the recognition of well productivity.