沉积岩致密油藏压裂裂缝导流能力及产能模型

Models for Conductivity and Productivity of Hydraulic Fractures in Tight Oil Reservoirs in Sedimentary Rocks

为明确不同类型沉积岩储集层压裂开发后导流能力的变化规律,通过开展浊积岩、滩坝砂、砂砾岩等沉积岩压裂后导流能力测试实验,分析了岩性与导流能力之间的关系,构建了导流能力模型。将导流能力模型引入主裂缝压力控制方程,得到主裂缝压力解析解;应用分布式体源方法建立了水平井多段压裂产能预测半解析模型。将新产能预测模型应用于大庆长垣外围朝阳沟油田致密油藏,数值模拟模型、不考虑岩性产能模型和考虑岩性产能新模型的计算误差分别为6.5%、22.7%和4.6%,新的模型侧重于不同沉积岩岩性对产能的影响,提高了致密油藏产能预测精度。

In order to clarify the variation in the conductivity of different types of sedimentary rocks after fracturing,post‐frac conductivity tests were conducted on the sedimentary rocks such as turbidite,beach‐bar sandstone,and sandy conglomerate to identify the relationship between lithology and conductivity,and a conductivity model was constructed.The conductivity model was then incorporated into the pri‐mary fracture pressure control equation to obtain an analytical solution for primary fracture pressure.A semi‐analytical model for predicting the productivity of multi‐stage fractured horizontal wells was developed by using the distributed volume source method.The new productivi‐ty model was applied to the tight oil reservoirs in the Chaoyanggou oilfield in the periphery of Changyuan,Daqing.It is found that the calcu‐lation errors from a numerical model,a productivity model without considering lithology and the new productivity model considering litholo‐gy are 6.5%,22.7%and 4.6%,respectively.The new model focuses on the impact of different sedimentary rock lithologies on productivity,