页岩储层压裂组合支撑剂导流能力预测模型及应用研究

A Study on the Prediction Model and Application of the Diverting Capacity of Composite Proppants

郭建春 马健 曾凡辉 穆轲帆 赵志红

GUOJianchun MAJian ZENGFanhui MUKefan ZHAOZhihong

油气藏地质及开发工程全国重点实验室·西南石油大学, 四川 成都 610500 中国石化西南油气分公司工程技术研究院, 四川 德阳 610105

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China Engineering Research Institute, Southwest Petroleum Branch, SINOPEC, Deyang, Sichuan 610105, China

页岩储层通过水力压裂形成长期高导流能力裂缝是低渗透致密油气藏资源有效开发的核心。基于线弹性力学理论，通过改进Kozeny-Carman方程建立了支撑裂缝动态导流预测能力模型，避免了以往模型没有全面考虑支撑剂粒度组成、弹塑性变形、嵌入和蠕变的不足。结果表明，当有效闭合应力为60 MPa时，第1 000天的裂缝导流能力较第100天的裂缝导流能力下降大约54%；在低有效闭合应力下，大粒径支撑剂含量越高，支撑裂缝导流能力越大；当有效闭合应力增大时，加入小粒径支撑剂可以减小裂缝导流能力的下降幅度；支撑剂或裂缝壁面弹性模量越大，支撑剂的变形、嵌入量越小，支撑裂缝导流能力越大；支撑裂缝初始缝宽越大，支撑裂缝中支撑剂铺置层数越多，会减少因嵌入带来的不利影响，裂缝导流能力增加；随着时间、有效闭合应力的增加，支撑裂缝缝宽、导流能力会因支撑裂缝蠕变的影响而逐渐减小。

This paper develops a comprehensive prediction model for the diverting capacity of propped fractures using an improved Kozeny-Carman equation, incorporating factors such as proppant grain size composition, elastic-plastic deformation, embedment, and creep. The study reveals that fracture diverting capacity decreases by approximately 54% from the 100th to the 1000th day under an effective closure stress of 60 MPa. The presence of larger grain-sized proppants enhances the diverting capacity, especially at lower effective closure stresses. The addition of small grain-sized proppants can reduce the decline in capacity under higher stresses. A higher elastic modulus of the proppant or fracture wall correlates with less deformation and embedment, leading to greater diverting capacity. Additionally, larger initial fracture widths and increased proppant layering can improve capacity by minimizing embedment effects. The model also indicates that over time and with increased effective closure stress, fracture width and diverting capacity will gradually decrease due to creep.

10.11885/j.issn.1674 5086.2024.11.12.02