气井产能递减分析与预测研究

在分析气藏压力变化后气井储层渗流参数和流体参数变化特征的基础上，利用实例井测试和实验分析数据，分别提出了不同类型气井产能变化规律，对其递减规律进行了理论预测，并使用矿场数据进行了定量分析，且对比了常规研究方法，着重于对产能方程系数的变化分析，尝试利用先前获取的稳定试井资料分析储层压力大幅下降后的产能动态。结果表明，常规气井产能变化主要受流体状态参数的影响；储层压力低于露点压力后，凝析气井组分变化和凝析液析出控制着气井产能的递减；变形储层开采期间储层渗流参数的变化会加快气井产能的递减速度，用修正的勘探阶段测试数据来预测产能递减能够满足工程需要。研究可为优化不同类型气井工作制度提供参考。

Analysis and Prediction of the Deliverability Decline for Gas Well

Based on the characteristics of the changes of the seepage flow parameter and fluid parameters，the change lawsof the gas well deliverability for different types of gas reservoir are proposed by using on-site testing data and experimentalanalysis data of a gas well and the decline law is theoretically predicted，then the quantitative analysis and comparison withthe conventional methods are done by using the field data. In this paper，the analysis of the coefficients of the deliverabilityequation changes are emphasized，and also the deliverability performance after the precipitous pressure decline is studied byusing the well test data. It is shown that the deliverability of the dry gas well is mainly controlled by the fluid parameters；the rate of deliverability decline of the gas condensate well is affected by the composition change and the condensate dropoutwhen the reservoir pressure is below the dew point；the drawdown of the permeability and porosity during the developmentwill accelerate the deliverability decline in stress-sensitive gas field. By correcting the previous well testing data to predict thedecline performance for the above gas reservoir，it can satisfy the demand of productivity prediction and thus presents a basisfor the study of deliverability decline in gas reservoirs.