Title

Influencing factors of hydraulic propped fracture conductivity in shale reservoir

作者

刘学伟

Authors

LIU Xuewei

单位

中国石油大港油田分公司石油工程研究院，天津 300280

Organization

Research Institute of Petroleum Engineering, PetroChina Dagang Oilfield Company, Tianjin, 300280, China

摘要

支撑裂缝的导流能力是评价页岩储层水力压裂施工效果的一项重要参数，其大小受到多种因素影响。文中开展了支撑剂类型、颗粒大小、铺砂浓度等对支撑裂缝导流能力影响的室内实验研究。结果表明：陶粒的导流能力明显高于石英砂和覆膜砂，在低闭合压力条件下，20~40目陶粒的导流能力最大，在高闭合压力条件下，组合支撑剂的导流能力明显高于单一支撑剂；铺砂浓度越大，裂缝导流能力越大；循环应力加载模式下，裂缝导流能力比稳载时下降了31.7%，经过滑溜水和胍胶压裂返排液污染后，裂缝导流能力分别下降了33.9%和76.5%。研究成果指导了X-4井的现场压裂施工，该井措施后产气量较高且稳定生产，压裂增产效果较好。

Abstract

The conductivity of propped fractures is an important parameter for evaluating the effect of hydraulic sand fracturing in shale reservoirs, and which is often affected by many factors. Therefore, laboratory experiments on the effects of proppant type, particle size, sand concentration, cyclic stress and fracturing fluid backflow on the fractures conductivity were carried out, and on this basis, the design of on-site fracturing technology was guided. The results show that the conductivity of ceramsite was obviously higher than that of quartz sand and coated sand; under low closure pressure, 20-40 mesh ceramsite has the greatest conductivity, while under high closure pressure, the conductivity of composite particle proppant was obviously higher than that of single particle proppant. The larger the sanding concentration was, the larger the fracture conductivity was. The impact of cyclic stress change and fracturing backflow fluid on the supporting fracture conductivity of shale reservoir was greater. Under cyclic stress loading mode, the fracture conductivity decreased by 31.7% compared with that under steady loading. Bacause of the pollution of slippery fracturing backflow fluid and guanidine gum fracturing backflow fluid, the fracture conductivity decreased respectively by 33.9% and 76.5%. Referring to the above research results, in-situ fracturing of well X-4 has been carried out. After the measures, the gas production of the well was relatively high and stable, which has played a good fracturing stimulation effect.

关键词：

页岩储层; 水力压裂; 支撑裂缝; 导流能力; 影响因素;

Keywords:

shale reservoir; hydraulic fracturing; propped fracture; conductivity; influencing factors;

基金项目

DOI

10.6056/dkyqt202003025

页岩储层水力压裂支撑裂缝导流能力影响因素