某超高压气田气井生产动态异常数据诊断和分析

 某超高压气田受井况影响,气井在投产一段时间后出现流压下降速度快、流压变化趋势与产量不匹配等生产曲线严重失真现象,影响了对气井真实动态特征的认识.这种异常生产曲线,如何去伪存真并还原气井的真实生产动态是该气田动态分析中首先要解决的问题.建立了从异常生产曲线诊断筛选—正常数据跟踪分析解释—解释结果可靠性验证的一整套异常曲线分析方法.首先根据现代产量递减分析基本原理和超高压气藏PVT特征,建立了简化的超高压气井标准流动特征曲线,依据标准特征曲线对气井生产曲线异常数据点进行甄别与剔除,筛选出正常生产数据点;然后对正常数据点进行分析解释确定气井的储渗参数,在此基础上建立单井动态模型对生产历史进行跟踪修正;最后依据连通气藏特征建立了解释结果可靠性验证方法.实现了异常生产曲线的去伪存真和气井真实生产动态的还原.

Diagnosis and Analysis of Well's Abnormal Performance Data in an Over-pressured Gas Field

Due to the blocking of the screen section at the bottom of the tubing, the observed bottom-hole flowing pressure in the production wells of an over-pressured gas field might show an unexpected sudden drop, frequent fluctuations and some inconsistent changes with the flow rates, to mask the true behavior of the production wells. With the universal, everlasting poor quality of the flowing data, the identification of the abnormal data and the restoration of the true behavior are crucial in the well performance analysis. This paper proposes a simplified data diagnosis method based on the theory of the advanced production decline analysis and the PVT property of the over-pressed gas reservoir, to process the well production history data and to identify and filter the abnormal data. Then, the processed production data are analyzed through the type-curve matching to calculate the well and reservoir parameters, including the skin, the permeability, and the initial gas in the place. Based on these parameters, single well analytical models are built to generate the well true production history. In the end, the generated well production history is verified.