一种利用生产动态历史评价异常高压气井产能的新方法

A new method for evaluating the productivity of abnormal high pressure gas well by using the dynamic production history data

异常高压气藏井下地层压力监测及产能试井存在井口压力高、井控风险大、井底温度压力高、数据稳定性差、油管损伤大等现实问题,导致常规产能试井应用规模受限。通过对气井产能评价方法的研究,在利用井口油压考虑动能项确定井底流压的基础上,应用气井的生产动态数据对单井产能进行评价,并据此计算气井的地层压力(PR)、层流系数(a)、紊流系数(b),建立气井产能方程实现气田实时产能评价,制定单井合理产能与气田合理产量。实例应用表明,利用地面生产动态数据确定的气井无阻流量与实测井底压力得到的无阻流量的相对误差仅为2.75%,验证了利用地面生产动态资料评价气井产能的合理性。该方法不仅节约了测试成本和消除了测试风险,同时给气藏动态分析、跟踪数值模拟与气藏管理提供了科学依据,对同类型异常高压气藏开发具有一定的借鉴和指导意义。

High well head pressure, big well control risks, high bottom hole temperature, poor data stability and severe tubing damage etc.are the challenges existing in the operation of formation pressure monitoring and well productivity testing of abnormal high pressure gas reservoir which limits the application scale of conventional productivity testing.Through the research on the methods of gas well productivity evaluation, based on the bottom hole flow pressure determined by well head oil pressure while considering the dynamic parameters to evaluate the single well productivity using the dynamic production data of gas field and on the basis of this to calculate the gas well formation pressure P, laminar flow coefficient a, turbulent flow coefficient b,the gas well deliverability equation was established to evaluate the real-time productivity of gas field and to determine the reasonable productivity of single well and reasonable production of gas field. The application example shows that the relative error of AOF is only 2.75~ between gas well absolute open flow（AOF） confirmed by surface dynamic production data and AOF measured by actual bottom hole pressure which proved the rationality of evaluation of gas well productivity by using of surface dynamic production data.Application of this new method not only saves testing operation cost and eliminates the testing risk,at the same time it provides a scientific basis for gas reservoir dynamic analysis, tracking data simulation and gas reservoir management, and offers reference and guiding suggestion for similar abnormal high pressure gas reservoir development.