凝析气藏相态恢复理论研究

STUDY ON THE PHASE-STATE RESTORARION OF GAS CONDENSATE RESERVOIRS

凝析气PVT分析数据是进行气藏数值模拟及开采工艺设计的重要参数 ,但由于各种原因在气藏开发初期未能取得代表性PVT样品或未进行取样 ,以至使开发方案设计不能正常进行 ;相态恢复方法是解决此问题的常用方法之一 ,但目前有关相态恢复理论的系统研究较少。因此首先给出了凝析气藏相态恢复一般原理 ,在对塔里木英买 7井凝析气PVT数据拟合后 ,研究了地层压力下降到不同程度采出井流物直接进行相态恢复和将此井流物进行一级分离后 ,用目前分离器油和分离器气按原始生产气油比进行配样而得到的原始流体相态特征以及按地层压力等于露点压力配样 。

PVT data of gas condensate reservoir provide important parameters for reservoir numerical modeling and recovery planing. For various reasons, however, representative PVT samples of the initial development phase are often not available. Phase-state restoration is one of the methods usually used to solve this problem; but systematic study on the theories behind phase-state restoration is lacking. In the present work, the general principles of phase-state restoration of gas condensate reservoirs and their application to the Yinmai Well 7 in Tarimu basin are given. After data matching, phase-state restoration was performed directly on the effluents from the well at different formation pressure drawdowns. Restoration was also performed on mixed separator oil and gas samples assuming the GOR of the initial production phase or assuming a formation pressure equal to the dew pressure. Comparison is made on the influence of the two types of restoration on the fluids as being representative of the initial formation fluids.