压裂多级裂缝内流量分布规律  

Study on Flowrate Distribution of Fracturing Fluid in Multi-Stage Fractures

作　　者：吴峙颖[1,2] 路保平 胡亚斐[2] 蒋廷学[1] 眭世元[1] WU Zhiying;LU Baoping;HU Yafei;JIANG Tingxue;SUI Shiyuan(Sinopec Research Institute of Petroleum Engineering,Beijing 100101;Research Institute of Petroleum Exploration and Development,CNPC,Beijing 100083)

机构地区：[1]中国石化石油工程技术研究院,北京100101 [2]中国石油勘探开发研究院,北京100083

出　　处：《钻井液与完井液》2020年第4期532-535,共4页Drilling Fluid & Completion Fluid

基　　金：中国石化科技攻关项目“深层页岩气高导流复杂缝网压裂关键技术”(P20046-3)。

摘　　要：当前,以页岩油气为主的非常规油气藏开发力度日益加大,水力压裂是开发该类储层的核心技术。在该类储层的开发过程中,往往采用多级复杂裂缝压裂技术,但目前针对压裂过程中各级裂缝内流量分布规律研究甚少,而该规律对认识裂缝、指导压裂方案至关重要。为了研究压裂过程中多级裂缝内的流量分布规律,自主研制了多级裂缝系统有效输砂模拟实验装置,在模拟多级裂缝情况下,开展了不同压裂液黏度、支撑剂粒径、注入排量、砂比等因素对各级裂缝内流量的影响规律实验研究。研究结果表明,各级裂缝中流量占比逐级减小,主裂缝占比平均为64.63%,一级分支缝平均为22.14%,二级分支缝平均为13.23%;各级裂缝中流量分布比例主要受总流量大小影响,流量越大,主裂缝中流量占比越高,分支缝中流量占比越低,其次依次为支撑剂粒径、压裂液黏度和砂比。通过研究形成了一套多级裂缝内流量分布规律评价方法,揭示了各级裂缝内流量分布规律,为认识裂缝、优化压裂设计方案提供了依据。Hydraulic fracturing is the core technology for the more and more prevailing development of unconventional hydrocarbon such as shale gas.Multistage fracturing has always been used in the development of unconventional hydrocarbon reservoirs.Study on the flowrate distribution in each level of fractures during fracturing has seldom conducted,although the understanding of the flowrate distribution is very important to the understanding of fractures and to the design of fracturing program.An apparatus for experimenting effective sand transport in multistage fractures was developed to study the flowrate distribution in multistage fractures.Using this apparatus,several factors,such as viscosity of fracturing fluid,particle size of proppant,injection rate,sand concentration etc.,were studied for their effects om the flowrate distribution of fracturing fluid in multistage fractures.It was found in the study that flow rate was decreasing along the fractures in different descending stages.64.63%of the flow rate is in the master facture,22.14%in the first level fractures,and the rest in the second level fractures.The distribution of flowrate in different levels of fractures is also affected by the total flowrate;the higher the total flowrate,the higher the flowrate distributed in the master fracture and the lower the flowrate in the sub-fractures.Other factors,according to their level of importance,are the particle size of proppant,viscosity of fracturing fluid and sand concentration.The study gives birth to a method of evaluating the pattern of flowrate distribution in multistage fractures and reveals the pattern of flow rate distribution in each level of fracture,providing a basis on which the properties of fractures can be understood and fracturing program can be optimized.

关 键 词：压裂液 多级裂缝 流量分布 物理模拟 

分 类 号：TE357.12[石油与天然气工程—油气田开发工程]