Abstract：Wellbore instability occures easily in jointed broken formation. The nonlinear statics problem is solved by transforming it into dynamics problem using dynamic relaxation method of the discrete element method. The stresses，displacement and fracture stretch situation near the coal wellbore are calculated by deformable discrete element method. Two-dimentional discrete element UDEC program is applied in fissure-plane seepage calculation.The result show that the drilling fluid weight plays an important role in wellbore stability，and the capacity of drilling fluid is also important.
李嗣贵1 邓金根1 李明志2. 节理破碎地层井壁稳定的离散元分析[J]. 岩石力学与工程学报, 2002, 21(S): 2139-2143.
Li Sigui1， Deng Jingen1， Li Mingzhi2. DISCRETE ELEMENT ANALYSIS ON WELLBORE STABILITY IN JOINTED BROKEN FORMATION. , 2002, 21(S): 2139-2143.
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2002, Vol. 21 
