樊庄北部3号煤层现今应力场分布数值模拟

发布时间：2018-11-01 10:37

【摘要】：为了制定针对樊庄区块北部煤层气井区3号煤层的有效缝网改造措施,利用工区二维地震资料对石炭系一一二叠系的构造样式及断层特征进行解释,在此基础上,利用压裂法、成像测井及有限元数值模拟方法对山西组3号煤层现今应力场特征进行研究。结果表明,3号煤层主应力满足σ_Hσ_vσ_h,各主应力随深度的增加而增加,σ_v、σ_H及σ_h的应力梯度分别为0.025 MPa/m、0.018 MPa/m及0.013 MPa/m。3号煤层的σ_H及σ_h均略高于其顶底板砂泥岩地层1.0~2.5 MPa,这种应力特征易造成压裂穿层,缝高难于控制;3号煤层σ_H-σ_h为2.0~6.0MPa,且随深度增加而增加,这是造成工区埋深相对较浅的煤层压裂效果较好、产气量相对较高的重要原因。研究区现今地应力方向在SN及NNE之间,与喜马拉雅中晚期构造挤压运动相关。有限元模拟显示,煤储层应力场平面分布特征受控于埋深、岩性、褶皱及断层等因素。3号煤层σ_H为15.6~21.0MPa;σ_h为12.5~16.0MPa,预测结果与实测值相符。
[Abstract]:In order to make effective measures of fracture network reconstruction for No. 3 coal seam of coalbed methane well area in northern Fanzhuang block, the structural style and fault characteristics of Carboniferous / Permian system are interpreted by using two-dimensional seismic data in the working area. On the basis of this, fracturing method is used. The present stress field characteristics of No. 3 coal seam in Shanxi formation were studied by imaging logging and finite element numerical simulation. The results show that the principal stress of No. 3 coal seam satisfies 蟽 _ H 蟽 _ v 蟽 _ h, and the principal stresses increase with the increase of depth. The stress gradient of 蟽 _ v, 蟽 _ H and 蟽 _ h are 0.025 MPa/m, respectively. 蟽 _ H and 蟽 _ h in 0.018 MPa/m and 0.013 MPa/m.3 coal seams are slightly higher than 1.0 ~ 2.5 MPa, in sand and mudstone strata of top and bottom plates. The stress characteristics of 0.018 MPa/m and 0.013 MPa/m.3 coal seams can easily lead to fracturing through layers and the fracture height is difficult to control. The 蟽 _ H- 蟽 _ h of No. 3 coal seam is 2.0 ~ 6.0MPa and increases with the increase of depth, which is an important reason for the better fracturing effect and the higher gas production in the coal seam with relatively shallow buried depth in the working area. The present stress direction in the study area lies between SN and NNE, which is related to the tectonic compressional movement in the late Himalayan. The finite element simulation shows that the plane distribution characteristics of stress field in coal reservoir are controlled by factors such as buried depth, lithology, fold and fault. The 蟽 _ H and 蟽 _ h of coal seam No. 3 are 15.621.0MPa and 12.5g / 16.0MPa, respectively. The predicted results are in agreement with the measured values.
【作者单位】：西安石油大学地球科学与工程学院;中国地质大学(北京)能源学院;山东新汶矿业集团有限责任公司;西南石油大学地球科学与技术学院;
【基金】：国家自然科学基金(41572130,41372139,41072098) 国家科技重大专项(2011ZX05018-001,2011ZX05009-002,2011ZX05033)
【分类号】：P618.13

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