大牛地气田一点法产能结果评价

大牛地气田为低孔、低渗、致密砂岩气田，气井在完井测试时为了减少放空气量，多数采用一点法产能试井，并计算气井无阻流量。由于一点法产能试井计算气井无阻流量公式中的经验参数α值在各气田之间有较大差异，故确定该气田的α值，对正确计算气井的无阻流量有着重要作用。为此，通过对该气田的修正等时试井资料进行重新整理，分析了产能指示线出现异常不能整理产气方程的原因，并按异常试井资料修正方法进行处理，获得了各气井的产能方程，计算出经验参数α，建立了大牛地气田一点法产能经验公式，并比较了不同气区经验公式之间计算结果的差异，分析了产生差异的原因，提出了在一点法试井中为提高无阻流量计算精度应采取的测试措施。

ANALYSIS OF SINGLE-POINT WELL TEST IN DANIUDI GAS FIELD

Daniudi gas field is featured by low porosity, low permeability, and compacted sandstones. To reduce the amount of gas discharged into air, single point well test was usually applied and open flow potential was calculated after completion. Therefore, it is important to determine the experience parameter α in the equation of open flow capacity. In this paper, isochronal well test data of Daniudi gas field were summarized to analyze the causes of abnormal productivity index curves and calculate α for an individual well after correction of the abnormal well test data. Differences of the experience equations for different regions were compared and the causes were analyzed to come up with test procedures to improve the accuracy of open flow capacity calculation in single point well tests.