部分射开井流线数值试井解释模型及压力响应

Streamline numerical well-testing interpretation model and pressure response for partially perforated wells

建立了部分射开井的流线数值试井解释模型,模型包括生产阶段的渗流数学模型和测试阶段的流线数学模型,采用流线方法和有限差分方法分别对生产和测试阶段的数学模型进行数值求解,得到了部分射开井的压力响应特征曲线。对流线分布和压力响应特征曲线的综合分析表明,部分射开井的压力导数曲线出现两条水平直线段。研究了渗透率比、射开厚度比、射孔部位对压力响应特征的影响,结果表明,渗透率比越大,第2条径向流水平直线段出现的时间越早;射开厚度比越小,两条水平直线段的高度差越大;射开部位对压力响应的影响不大。认为渗透率比和射开厚度比对压力响应有较大的影响,是试井解释必须考虑的重要影响因素。

A streamline numerical well-testing interpretation model for partially perforated wells was established that includes a filtration mathematical model of production period and a streamline mathematical model of testing period. Pressure response characteristic curves for partial perforated wells were obtained by solving the models of the two periods using streamline method and finite difference method, respectively. Pressure response characteristics for partially perforated wells were obtained by analyzing synthetically the streamline distribution and the pressure response characteristic curves. Two horizontal straight line segments will emerge in the derivative curve. The influence of permeability ratio, perforation thickness ratio and perforation location on pressure response was investigated. The larger the permeability ratio is, the earlier the second horizontal straight line segment will emerge. The less the perforation thickness ratio is, the greater the distance between the two horizontal straight line segments will be. The impact of perforation location on pressure response is little. Permeability ratio and perforation thickness ratio have significant effects on the pressure response and they must be taken into account in well-testing interpretation for partially perforated wells.