测试压力曲线在海拉尔油田压裂选层中的应用

Application of test pressure curves in selecting fracturing layers in Hailaer oilfield

海拉尔油田压裂后约44%试油层为低产层或干层,改造有效率低,需要建立一套适用该区块的压裂选层评价方法。统计103口地层测试施工后的压裂试油井资料,进行测试压力曲线形态与压裂效果的相关性研究,分析储层信息与压裂增产潜力的关系。根据测试开井流动曲线、关井压力恢复曲线反映的地层渗流能力、污染程度、压力系数、能量衰竭等信息,将测试压力曲线分为常压高渗型、污染堵塞型、特低渗透型、能量衰竭型(低压型)四类,制定测试压力曲线分类图版,指导压裂选井选层。经37口井压裂选层现场应用,综合符合率达到92%以上。该方法适用于试油方案优化、老井复查、压裂选层等方面,显著提高海拉尔油田储层改造有效率。

In the Hailaer Oilfield,approximately 44%of the layers tested after fracturing are either low-production or dry,indicating a low efficiency of the stimulation process.This necessitates the establishment of an evaluation method for fracturing layer selection that is suitable for this block.By analyzing the fracturing and testing data from 103 wells,the correlation between test pressure curve patterns and fracturing outcomes was investigated,and the relationship between reservoir characteristics and the potential for increasing production through fracturing was analyzed.According to the formation,including formation permeability,contamination level,pressure coefficient,and energy depletion,reflected in the test well opening flow curves and well shut-in pressure recovery curves,the test pressure curves are categorized into four types:normal pressure high permeability,contamination blockage,ultra-low permeability,and energy depletion(low pressure).A classification chart for test pressure curves was developed to guide the selection of wells and layers for fracturing.Field application of this method in 37 wells achieved a comprehensive conformity rate exceeding 92%.This approach is applicable to optimizing oil testing schemes,re-evaluating old wells,and selecting layers for fracturing,significantly enhancing the efficiency of reservoir stimulation in the Hailaer Oilfield.