一种气井产能分析的改进方法

A new method of gas well deliverability analysis

目前气井产能分析大多采用稳定试井来进行解释,但该解释方法要求必须在测试工艺上满足稳定测试的条件,然而在矿场的实际生产过程中,由于各种因素的影响,在稳定测试条件不满足时就测试了井口产量和井底流压,导致绘制出的二项式产能指示曲线斜率为负值,使之无法计算该井的无阻流量。特别是在求取低渗透气藏的产能方程时,若要达到回压试井所要求的稳定测试时间,则显得较长,不利于气田的正常生产。而且由于供气的需要,不允许关井进行压力恢复,这样就不满足稳定试井的条件,求出的气井产能方程便不能准确地计算无阻流量。本文针对此类情况,提出了一种在不关井的情况下,求取气井二项式产能方程的改进方法,不需要开井生产前的地层压力,只需几组开井不稳定生产时的产量和流压,就能求出气井的产能方程和无阻流量。通过矿场实践表明,该方法具有一定的实用价值。

At present, most of the gas well deliverability analysis use systematic well testing, but it has to meet the requirements of steady test, however, in the practice of field, because of some uncertain factors, they begin to test the well flow rate and bottom hole flowing pressure without steady test condi- tion and result in negative value of the slope of binomial deliverability index curve, which makes the calculation of it＇s AOF become impossible. Especially in the acquirement of deliverability equation of low permeability gas reservoir, if we have to access to the stable testing time that the backpressure test needs, which is too long to harm of the gas field production. And the requirement of gas supply, shut in for the build--up is not allowed, so it can＇t meet the requirements of systematic well testing, so we can＇t calculate the AOF accurately in the gas well deliverability equation. So this paper puts forward a new method to acquire gas well binomial deliverability equation without shut in. the new method can acquire the gas deliverability equation and AOF＇with several groups of has showed that the new method is practicable. production rate and flowing pressure . The field practice