水力压裂条件下“三软”煤层压裂渗透模型及应用

发布时间：2018-01-16 21:30

本文关键词：水力压裂条件下“三软”煤层压裂渗透模型及应用　出处：《天然气地球科学》2017年03期 　论文类型：期刊论文

【摘要】：为了探索水力压裂条件下由软煤、软顶和软底构成的特殊地质体(简称"三软"煤层)裂缝的扩展规律,以及压裂后储层的裂隙分布特征,结合河南焦作煤层气田的注水压裂试验,基于PKN模型的裂缝宽度假设与裂缝流动的摩阻压降规律,着重考虑软煤裂隙中压裂液的滤失因素,构建了水力压裂条件下"三软"矿区碎裂煤的裂缝扩展模型与渗透率计算模型,并运用地震实测法和渗透率反演计算法分别进行了验证。研究结果表明,实际施工条件下试验区二_1煤层压裂后的裂缝几何特征大致相同,长度分布区间为81.85~139.23m,平均为100.41m;最大裂缝宽度区间为24.83~32.78mm,平均为27.32mm,裂缝长度与地震实测结果基本一致。应用裂缝渗透模型,进一步计算得到压裂后煤储层的渗透率一般在(9.21~86.61)×10~(-3)μm~2之间,平均为31.63×10~(-3)μm~2。与后期排采结果所得到的储层渗透率反演值相对比,二者基本吻合。由此可见,压裂改造后的煤储层的渗透率得到显著提高,裂缝扩展与裂缝渗透模型皆可应用于指导"三软"矿区的压裂抽采实践与产能预测。
[Abstract]:In order to explore the conditions of hydraulic fracturing by special geological soft coal, soft top and soft bottom form (referred to as the "Three Soft" coal seam) propagation of cracks, and after fracturing reservoir fracture distribution characteristics, combined with the water filling test of Henan Jiaozuo coal seam gas fracturing, the frictional pressure drop of crack width and crack flow hypothesis PKN model based on the consideration of fracturing fluid in fracture of the soft coal filtration factors, construction of hydraulic fracturing under the condition of "Three Soft" coal mine burst crack propagation model and calculation model of permeability, and the use of seismic measurement and permeability inversion proved by calculation method respectively. The results show that the crack geometric characteristics of actual construction conditions under the test area of two _1 coal seam after fracturing is roughly the same length distribution range of 81.85~139.23m, the average is 100.41m; the maximum crack width range of 24.83~32.78mm, the average is 27.32mm, and the crack length The earthquake is basically the same measured results. Application of fracture permeability model, further calculated after fracturing of coal reservoir permeability in general (9.21~86.61) * 10~ (-3) m~2, with an average of 31.63 * 10~ (-3) m~2. reservoir permeability inversion and post drainage results obtained were compared, the two basic well. Thus, the coal reservoir permeability after fracturing to significantly improve the mining practice and prediction of crack propagation and crack penetration capacity of pumping model can be applied to guide the "Three Soft" mining fracturing.

【作者单位】：郑州大学水利与环境学院;河南省煤田地质局;河南省能源钻进工程技术研究中心;
【基金】：国家自然科学基金项目(编号:41272339)资助
【分类号】：TE377
【正文快照】： (3):349-355.[王志荣,贺平,郭志伟,等.水力压裂条件下“三软”煤层压裂渗透模型及应用[J].天然气地球科学,2017,28(3):349-355.]0引言河南省“三软”矿区煤岩储层的地质条件比较复杂,具有低孔隙、低渗透、低地层压力以及高构造变动,即“三低一高”的煤层气储藏特征,在开发过程

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