致密气藏水平井测井产能预测方法研究

Log-based Productivity Evaluation for Horizontal Wells in Tight Gas Reservoir

苏里格气田×区具有孔隙度小、渗透率低、孔隙结构复杂、各向异性和非均质性强等特点。在水平井开发过程中,由于测井系列少,水平段物性变化大,难于给出合适的解释标准,多级分段压裂难以优选射孔层段,评价水平井产能成为难点。通过构建综合反映储层物性、岩性、电性的综合指数,对水平段分段分级评估,基于简化油藏渗流模型,利用测井资料分别计算各类储层的产能指数,与试油资料相结合得到了该区的产能预测模型。应用综合指数能很好地划分储层类型并指导射孔层段的优选,该产能预测方法只需测井参数,操作简单,预测精度高。

The X area of Sulige gas field has the characteristics of low porosity, low permeability, complex pore structure, strong anisotropy and heterogeneity. During the development with horizontal wells, it was difficult to establish appropriate interpretation standard, select which intervals to perforate when fracturing at multiple stages, and therefore hard to evaluate the productivity of the horizontal wells, because of insufficient log data and different reservoir physical properties of the horizontal sections. In this study, comprehensive indicators are introduced to reflect the lithologic, physical and electrical properties of reservoirs, so that the horizontal sections can be classified and evaluated. Then based on a simplified reservoir seepage model, the productivity of every reservoir is calculated using logging data. Finally, a productivity prediction model of a block is built by considering well test data. Comprehensive indicators can be used to classify reservoirs and select intervals to perforate. Only with logging parameters, the productivity prediction method is very easy to use and gives very accurate prediction.