致密气藏一点法公式在大牛地气田的应用

Single Point Method of Tight Gas Reservoir Applied in Daniudi Gas Field

大牛地气田应用原有一点法计算无阻流量,长期实践证明结果偏大并导致配产不合理、压降过快,同时理论上常规一点法在致密气藏产能评价中存在着误差偏大和适用性差等问题。为了解决以上问题,利用气田已有的一点法试井资料,结合产能公式推导理论和致密气藏渗流特征,对指数式进行修正,得出了不同层位的一点法公式,大大提高了一点法的适用性,并在实际生产中指导合理配产,显著增加了气井的开发效果,证明该方法是切实可行的。

Daniudi gas field calculate the open flow with single point test applied.Long-term results proved too large,lead to proration unreasonable and excessive pressure drop.Routine single point test formula commonly is measured by multi-point well testing with long test time and high costs.On the other hand,it exists too large error and is not very adaptable in productivity evaluation in site of tight gas reservoirs.To solve above problems,the common exponential function on the basis of tri-item equation to obtain new productivity formulas of different layers was revised,and then to obtain new single point test formulas of different layers from the existing gas well data of single point test,considering actuating pressure gradient and combining with theoretical derivation of productivity formula and tight gas reservoirs gas flow characteristics.Finally the contrast analysis of examples shows that the method is feasible.