涪陵焦石坝区块页岩气井弹性产率变化规律研究

A STUDY ON CHANGING LAWS OF UNIT PRESSURE DROP FOR GAS PRODUCTION OF SHALE GAS WELLS IN THE FULING JIAOSHIBA BLOCK

为了准确的评价页岩气井各阶段的生产特征,探寻其生产动态变化规律,采用弹性产率作为描述页岩气井生产动态的主要技术指标。通过理论推导与现场实际相结合的方法,明确了涪陵焦石坝区块页岩气井的弹性产率变化规律及其主控因素。研究表明,页岩气井采用控压定产生产方式,弹性产率随地层压力的下降而逐渐增加,后期受气体偏差系数的影响,会出现拐点,略微下降,并且弹性产率的变化与气井本身能力、现场合理配产等因素密切相关。同时,该指标的合理应用,可在区块开发趋势预测、单井合理工作制度优选等方面提供有意义的借鉴。

In order to evaluate production characteristics precisely at different production stages of shale gas wells,and to explore the law of dynamic change production,using the unit pressure drop for gas production as a main technical index for describing production characteristics of shale gas wells, this paper figures out the changing laws of unit pressure drop for gas production of shale gas wells and the main factors affecting the unit pressure drop for gas production through the way of combing theory with practice. This study shows that unit pressure drop for gas production will always increase by adopting the production mode of controlling the production pressure drop and producing rational in the whole life of shale gas wells,Meanwhile,the increasing will stop after the gas well reaches a certain accumulated postpartum. In addition,the unit pressure drop for gas production is mainly affected by the gas well's initial production capacity and the rational proration. Besides,this paper also points out that the reasonable application of this technical index is of great significance to the prediction of block development trend and the selecting of the single well's rational proration.