气井多相流水击数学模型的建立和求解

发布时间：2018-04-23 19:53

本文选题：水击 + 气井　；参考：《石油学报》2017年07期

【摘要】：针对气井关井瞬间产生的水击现象,由于井筒多相流和高压、高温以及天然气的强可压缩性特征,用于水力学的常规水击压力模型难以适用。基于水力学水击理论,分析气井水击机理,根据质量守恒定律和牛顿第二定律,建立由运动方程和连续性方程组成的描述气井多相流水击压力的数学模型;根据该方程属于拟线性双曲偏微分方程的特点,结合气井压力测试和应用需要,建立了两类边界条件:一类适用于通过井底压力计算井口及沿井深的水击压力,另一类适用于通过井口压力计算井底及沿井深的水击压力;通过特征线法对水击压力数学模型有限差分离散求解。计算结果与实测压力对比结果表明,水击压力模型能够精确地反映水击压力的大小、水击周期和水击衰减规律,从而提高压力恢复试井早期段数据质量,改善试井曲线拟合效果,提高试井解释准确度。
[Abstract]:Because of the characteristics of multiphase flow and high pressure, high temperature and strong compressibility of natural gas, the conventional hydraulic hammer pressure model used in hydraulics is difficult to apply. Based on the hydraulic hammer theory, the water hammer mechanism of gas well is analyzed. According to the law of conservation of mass and Newton's second law, a mathematical model is established to describe the multi-phase water hammer pressure of gas well, which is composed of motion equation and continuity equation. According to the characteristic that the equation belongs to quasilinear hyperbolic partial differential equation and combined with the need of gas well pressure test and application, two kinds of boundary conditions are established: one is suitable for calculating wellhead and depth water hammer pressure through bottom hole pressure. The other kind is suitable for calculating the water hammer pressure at the bottom of the well and along the well depth through the wellhead pressure and the finite difference discrete solution of the mathematical model of the water hammer pressure by the characteristic line method. The comparison between the calculated results and the measured pressure shows that the water hammer pressure model can accurately reflect the magnitude of the water hammer pressure, the water hammer period and the law of water hammer attenuation, so as to improve the data quality of the early stage of the pressure recovery test. The fitting effect of well test curve is improved and the accuracy of well test interpretation is improved.
【作者单位】：中国石油西南油气田公司川中油气矿;
【基金】：国家重大科技专项“复杂碳酸盐岩气藏开发技术研究”(2011ZX05015-003-005) 中国石油天然气集团公司重大勘探专项“四川盆地乐山—龙女寺古隆起含油气评价及勘探配套技术研究”(2012ZD01-03-01)资助
【分类号】：TE319;TE373

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