摘要
多段多簇水平井压裂技术作为页岩油藏的重要开发手段已经得到了广泛认同,压后关井能充分发挥渗吸的作用,提高单井压后产量,但目前压裂液渗吸作用区域一直是困扰油藏工程师的重要难题。本文以陇东页岩油藏多段压裂井为研究对象,基于物质平衡原理,利用渗流力学和岩石力学理论,建立了压裂施工过程中和压后关井过程中流体压力扩散数学模型,研究了压力扩散和压裂液波及体积随时间的变化关系。结果表明:压裂液波及体积随关井时间的增加逐渐增加,但增加的幅度会逐渐降低。储层渗透率越小,孔隙度越大,压裂施工时间越长,关井阶段井底压力越高,地层能量越高。该结果可为页岩油藏最佳关井时间的确定提供理论支持。
The multi-stage and multi-cluster horizontal well fracturing technology has been widely recognized as a vital development method for shale oil reservoirs.In this method,shut-in after fracturing can make full use of imbibition and increase the output of a single well after fracturing.The area of fracturing fluid imbibition remains,however,a major difficult problem puzzling reservoir engineers.This paper takes multi-stage fracturing wells in Longdong shale oil reservoirs as the research object to address this issue.Based on the principle of material balance,using seepage and rock mechanics theories,a mathematical model of fluid pressure diffusion during fracturing and shut-in after fracturing is established,and the relationship between pressure diffusion and the swept volume of fracturing fluid over time is studied.The results show that the swept volume of fracturing fluid increases gradually with the growth of shut-in time,while the increase amplitude can gradually decrease.The lower the reservoir permeability,or the greater the porosity,or the longer the fracturing construction time,the higher the bottom hole pressure during the shut-in stage,and formation energy becoming higher.This result provides a theoretical support for determining the optimal shut-in time for shale oil reservoirs.
作者
赵振峰
刘汉斌
杜现飞
徐创朝
赵号朋
ZHAO Zhenfeng;LIU Hanbin;DU Xianfei;XU Chuangchao;ZHAO Haopeng(Oil&Gas Technology Research Institute,PetroChina Changqing Oilfield Company,State Engineering Laboratory of Low-Permeability Oil&Gas Field Exploration and Development,Xi an,Shaanxi 710018;School of Energy Resources,China University of Geosciences(Beijing),Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering,Beijing 100083)
出处
《地质与勘探》
CAS
CSCD
北大核心
2022年第3期686-695,共10页
Geology and Exploration
基金
国家科技重大专项项目“致密油富集规律与勘探开发关键技术”课题四“致密油储层高效体积改造技术”(编号:2016ZX05046-04)资助。
关键词
页岩油藏
水平井压裂
压力扩散
压后关井
数学模型
陇东页岩油藏
shale oil reservoir
horizontal well fracturing
pressure diffusion
shut-in after fracturing
mathematical model
Longdong shale oil reservoirs
