本文關(guān)鍵詞： 水力壓裂 擴(kuò)展有限元法(XFEM) 應(yīng)力陰影效應(yīng) 多段壓裂　出處：《地震工程學(xué)報(bào)》2017年02期 　論文類(lèi)型：期刊論文

【摘要】：在實(shí)際的水力壓裂過(guò)程中,裂縫總是沿著垂直于最小地應(yīng)力的方向擴(kuò)展,地應(yīng)力的分布形式和多個(gè)壓裂段之間的互相影響(應(yīng)力陰影效應(yīng))對(duì)于形成復(fù)雜的裂縫網(wǎng)絡(luò)具有重要的影響。本文基于擴(kuò)展有限單元法(XFEM)模擬頁(yè)巖等多孔介質(zhì)在水壓作用下裂縫的任意擴(kuò)展,由于在傳統(tǒng)有限元法的基礎(chǔ)上引入了擴(kuò)充自由度和可以描述間斷的位移階躍函數(shù),所以裂縫可以獨(dú)立于網(wǎng)格擴(kuò)展,而不需要重新剖分網(wǎng)格。通過(guò)引入一維流動(dòng)假設(shè),求解潤(rùn)滑方程,并考慮流體在裂縫內(nèi)的流動(dòng)。同時(shí)也考慮裂縫向基質(zhì)中流動(dòng)的濾失效應(yīng)。研究實(shí)際施工中不同段間距下裂縫的擴(kuò)展模式和段間距對(duì)裂縫形態(tài)的影響,結(jié)果表明,壓裂段間距過(guò)小時(shí)中間的裂縫會(huì)被屏蔽;此外,裂縫會(huì)由于應(yīng)力陰影效應(yīng)而發(fā)生轉(zhuǎn)向。
[Abstract]:In the actual hydraulic fracturing process, the fracture always extends along the direction perpendicular to the minimum in-situ stress. The distribution of in-situ stress and the interaction between multiple fracturing sections (stress shadow effect) have important influence on the formation of complex fracture networks. In this paper, the expanded finite element method (XFEMM) is used to simulate the formation of shale and other porous media. The arbitrary propagation of cracks under the action of water pressure, Due to the introduction of extended degrees of freedom and displacement-step functions based on the traditional finite element method, cracks can be expanded independently of the mesh without the need to redivide the meshes. The lubrication equation is solved, and the flow of fluid in the fracture is considered. At the same time, the filtration failure due to the flow of the crack to the matrix is also considered. The effect of crack propagation mode and segment spacing on the fracture morphology under different segments spacing in actual construction is studied. Fractures in the middle of the fracturing interval are shielded, and the fractures turn due to the stress shadow effect.
【作者單位】： 蘭州大學(xué)土木工程與力學(xué)學(xué)院;寧夏大學(xué)物理與電子電氣工程學(xué)院;中國(guó)地震局黃土地震工程重點(diǎn)實(shí)驗(yàn)室;
【基金】：國(guó)家自然科學(xué)基金項(xiàng)目(51478444,51408567) 寧夏“十三五”重點(diǎn)建設(shè)學(xué)科項(xiàng)目
【分類(lèi)號(hào)】：TE357.1
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本文編號(hào)：1506681