A new reservoir simulation approach for fractured gas-condensate reservoirs

Abstract

To correctly simulate and predict the performance of fractured gas condensate reservoirs, based on the previous related studies, a new numerical dual porosity compositional simulation approach, suitable for fractured gas-condensate reservoirs, is proposed in this paper. Firstly, the proper pseudo-components should be correctly divided, and then single-matrix block models are built to establish the pseudo capillary pressure curve through comparing the single porosity model with the dual-porosity model. Based on the results, the dual-porosity compositional simulation method is studied. The study shows that dual-porosity compositional models can be used for fractured gas-condensate reservoirs without water drive, but not for reservoirs with strong water drive, whereas the model with pseudo capillary pressure curve can be correctly used for all kinds of fractured gas-condensate reservoirs. This new method was applied for a fractured gas-condensate reservoir of Tazhong No.1 gas field in the Tarim Basin, NW China, and the performance history of this field was well matched with the fitting error less than 5%. 摘要: ： 为了正确模拟裂缝型凝析气藏的开发动态，提出一种适合于裂缝型凝析气藏双重介质组分模型的数值模拟方法，即首先进行拟组分数的合理划分，然后建立单个岩块的单重介质精细模型和双重介质模型，调整双重介质模型的毛管力曲线拟合单重介质精细模型的计算结果，建立拟毛管力曲线，在此基础上开展双重介质组分数值模拟研究。研究表明，直接利用双重介质组分模型可以正确模拟裂缝型无水凝析气藏的生产动态；但对于裂缝型有水凝析气藏，模拟结果与实际生产动态偏差较大，而采用拟毛管力曲线后模型则可以获得正确的模拟结果。用该法对塔里木盆地塔中Ⅰ号气田某裂缝型凝析气藏的生产动态进行了模拟。结果表明，该方法可用于裂缝型凝析气藏的数值模拟，对实际气田开发动态拟合较好，指标拟合误差小于5%。图6表1参18 Key words: fractured, gas condensate reservoir, pseudo-component, pseudo-capillary pressure curve, numerical simulation