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

【摘要】：在實際的水力壓裂過程中,裂縫總是沿著垂直于最小地應(yīng)力的方向擴展,地應(yīng)力的分布形式和多個壓裂段之間的互相影響(應(yīng)力陰影效應(yīng))對于形成復(fù)雜的裂縫網(wǎng)絡(luò)具有重要的影響。本文基于擴展有限單元法(XFEM)模擬頁巖等多孔介質(zhì)在水壓作用下裂縫的任意擴展,由于在傳統(tǒng)有限元法的基礎(chǔ)上引入了擴充自由度和可以描述間斷的位移階躍函數(shù),所以裂縫可以獨立于網(wǎng)格擴展,而不需要重新剖分網(wǎng)格。通過引入一維流動假設(shè),求解潤滑方程,并考慮流體在裂縫內(nèi)的流動。同時也考慮裂縫向基質(zhì)中流動的濾失效應(yīng)。研究實際施工中不同段間距下裂縫的擴展模式和段間距對裂縫形態(tài)的影響,結(jié)果表明,壓裂段間距過小時中間的裂縫會被屏蔽;此外,裂縫會由于應(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;中國地震局黃土地震工程重點實驗室;
【基金】：國家自然科學(xué)基金項目(51478444,51408567) 寧夏“十三五”重點建設(shè)學(xué)科項目
【分類號】：TE357.1
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本文編號：1506681