马西凝析气藏试井解释方法研究

Well Test Interpretation Method for Maxi Condensate Gas Reservoir

由于凝析和反凝析现象的存在,凝析气藏流体在渗流过程中极易出现两相渗流,增加渗流阻力,压力恢复曲线呈现内区差、外区好的现象。针对传统凝析气藏渗流存在的主要问题,从渗流力学的微元法思想入手,建立了新的凝析气藏两区复合渗流数学模型;通过拉普拉斯变换方法和根据贝塞尔函数的基本性质,结合内外边界条件进行求解,获得了两区复合气藏气井井底压力响应数学模型;通过Stephest数值反演技术,获得了井底压力响应曲线,并对凝析气藏气井井底压力响应的影响因素展开分析和讨论;同时利用建立的数学模型对某凝析气井的实际压力资料进行了精细解释。研究结果表明,两区复合渗流数学模型与实际的试井测试资料吻合度高,对凝析气藏试井资料的精细解释具有一定的指导意义。

For the existence of the condensate and the anti-condensate phenomena, gas condensate reservoir fluid is extremely easily lost in the two-phase flow in the flow process, and increases the flow resistance, which leads to poor sign in inner zone and good sign outside the area in the pressure recovery curve. In view of the main problems in traditional gas condensate reservoir, starting from the micro-element method, a new two-zone composite flow model in gas condensate reservoir was established. Through Laplace transform and the basic properties of Bessel functions, we solved it combining with the boundary conditions inside and outside, and got bottom hole pressure response model in two-zone composite gas reservoirs. Through Stephest numerical inversion technique, we obtained the response curve of bottom hole pressure . Then we analyzed and discussed the bottom hole pressure response factors in composite gas reservoirs, and carefully explained information on the actual pressure recovery of some condensate gas wells. The research results showed that the two-zone composite model has a high matching degree with the practical well test data, which had certain guiding significance to the gas condensate reservoir on the fine interpretation of well test data.