射孔斜井产能预测新方法

从Besson公式的基础上引入双径向流模型,采用等值渗流阻力法,分射穿污染带与未射穿污染带两种情况推导出射孔斜井的产能公式。考虑了孔深、孔密、孔径、相位、污染带的半径与污染程度、压实带的厚度与压实程度、井斜角等因素对产能的影响。利用本文所推导的公式对射孔斜井产能进行参数敏感性分析,认为:产能指数对井斜角、孔深、孔密、压实程度、相位、孔径、压实带厚度的敏感性依次降低;产能指数对射孔参数和压实带参数的敏感性在未射穿污染带时比射穿污染带时高。

A new method to forcast the productivity of perforated slant well

Based on the model which used by Besson in the derivation of slant well productivity formula, this paper introduced a dual radial flow model and used equivalent flowing resistance method to presents productivity formulas of perforated slant well for two cases: damaged-zone penetrated and partially penetrated. The effects of perforation length, shot density, perforation diameter, phasing, the diameter and the pollution degree of the damaged-zone, the thickness and compaction damage degree of the crushed-zone, and deviation angle of the slant well are considered. Based on the derived formulas, sensitivity analysis on the performance of perforated slant well is conducted with the results showing that the sensitivity indexes of each parameters rank from high to low as follows: the deviation angle of the slant well, perforation length, shot density, permeability of the crushed-zone, phasing, perforation diameter and finally the thickness of the crushed-zone; the parameters of perforation and crushed-zone is less sensitive with respect to the productivity index when the damaged-zone is penetrated than that when the damaged zone is not penetrated.