水力壓裂作為深部能源開發(fā)的關(guān)鍵技術(shù),促進了現(xiàn)代石油工業(yè)的快速發(fā)展。為研究垂直井水力壓裂裂縫擴展機制和巖石破壞模式,開展了真三軸水力壓裂試驗和數(shù)值模擬研究,分析了主應(yīng)力差、注水排量、射孔角度和天然裂縫對水力裂縫擴展的影響。結(jié)果表明,灰?guī)r裂縫擴展模式主要分為兩類:單一垂直裂縫和縱橫向交叉復雜裂縫。高排量下巖體的破裂壓力更大,且易誘發(fā)二次壓裂;而變排量加載更容易誘發(fā)形成裂縫網(wǎng)絡(luò)。同時,灰?guī)r在壓裂過程中的聲發(fā)射波形幅值在0.01～0.02 m V范圍內(nèi),主頻保持在230～300k Hz范圍內(nèi)。當射孔角度θ=45°時,易產(chǎn)生與天然裂縫交匯的"T"型水力裂縫,而當θ=30°時,易產(chǎn)生X型裂縫。研究結(jié)果可為進一步研究灰?guī)r水力壓裂機理提供參考。

【文章頁數(shù)】：15 頁

【文章目錄】：
1 Introduction
2 Design and implementation of hydraulic fracturing test scheme
    2.1 Test scheme design
    2.2 Preparation of hydraulic fracturing sample
3 Test results and analysis
    3.1 Hydraulic fracturing curve and AE energy analysis
    3.2 Analysis of fracture propagation law in limestone hydraulic fracturing
        3.2.1 Single vertical fracture
        3.2.2 Transverse-longitudinal crossed fractures
4 Discrete element simulation of hydraulic fracturing of limestone
    4.1 Selection of micromechanical parameters
    4.2 Establishment and verification of hydraulic fracturing model
        4.2.1 Establishment of hydraulic fracturing model
        4.2.2 Calibration of fluid parameters
        4.2.3 Numerical simulation verification
    4.3 Hydraulic fracturing simulation of fractured limestone
5 Conclusions
Contributors
Conflict of interest



本文編號：4002386