横观各向同性地层水平井井壁拟三维应力场计算模型

发布时间：2018-06-12 21:39

本文选题：岩石力学 + 正交各向异性　；参考：《岩石力学与工程学报》2017年06期

【摘要】：针对横观各向同性地层,基于各向异性材料力学理论,运用应力叠加原理和坐标变换方法,考虑井筒流体压力、最大水平主应力、最小水平主应力和上覆岩层压力作用,推导横观各向同性地层中,水平井沿任意方向钻进时井壁应力场的拟三维解析解。进而分析了页岩和砂岩水平井井壁上任意岩石质点3个主应力的分布规律,分析表明,与地层力学性质各向同性条件相比,力学性质各向异性时,井壁上任意岩石质点的第一主应力σ_1没有改变,而第二主应力σ_2和第三主应力σ_3发生了改变,岩石力学性质各向异性度越大,主应力σ_2和σ_3改变越大,岩石力学性质高各向异性度增加了井壁可能发生张性破裂的点数。研究成果可为横观各向同性地层水平井水力裂缝起裂以及井壁稳定性分析提供参考。
[Abstract]:In view of transversely isotropic formation, based on anisotropic material mechanics theory, stress superposition principle and coordinate transformation method are used to consider the effects of wellbore fluid pressure, maximum horizontal principal stress, minimum horizontal principal stress and overlying rock pressure. The quasi three dimensional analytical solution of borehole stress field in horizontal well drilling along any direction in transversely isotropic formation is derived. Furthermore, the distribution of three principal stresses of arbitrary rock particles on the sidewall of shale and sandstone horizontal wells is analyzed. The analysis shows that, compared with the isotropic conditions of formation mechanical properties, the mechanical properties are anisotropic. The first principal stress 蟽 _ 1 of any rock particle on the sidewall has not changed, while the second principal stress 蟽 _ 2 and the third principal stress 蟽 _ 3 have been changed. The greater the anisotropy of rock mechanical properties, the greater the change of principal stress 蟽 _ 2 and 蟽 _ 3. The high anisotropy of rock mechanical properties increases the number of possible tensile fractures. The results can provide a reference for hydraulic fracture initiation and sidewall stability analysis of horizontal wells in transversely isotropic formations.
【作者单位】：西南石油大学油气藏地质及开发工程国家重点实验室;
【基金】：中国石化石油勘探开发研究院页岩油气富集机理与有效开发国家重点实验室开放基金(G5800 15 ZS WX042)~~
【分类号】：TE243

【相似文献】