Elastic Anisotropy of Source Rocks: Implications for Hydrocarbon Generation and Primary Migration
Elastic Anisotropy of Source Rocks: Implications for Hydrocarbon Generation and Primary Migration
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DOI：
10.1306/64ed8836-1724-11d7-8645000102c1865d
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发表时间：
1996-04
期刊：
影响因子：
3.5
通讯作者：
L. Vernik;C. Landis
中科院分区：
文献类型：
--
作者：
L. Vernik;C. Landis
我们将声速和各向异性测量与 X 射线衍射矿物学、Rock-Eval 有机地球化学分析、镜质体反射率和扫描电子显微镜观察相结合，对从 8 个沉积盆地收集的 69 个烃源岩岩心进行观察。速度数据表明压实黑色页岩中固体有机质（干酪根）的层状分布，并显示其弹性各向异性和有机质丰富度之间的强相关性。实验结果与从相对较低的 TOC 值开始在层理平行和层理法向上具有连续干酪根网络的黑色页岩双组分各向异性模型一致。致密、热成熟烃源岩的强弹性各向异性，在烃（HC）生成和R0大于0.75%的初次运移的主要阶段中，由于超压引起的层理-近平行微裂缝发育，进一步增强了致密、热成熟烃源岩的强弹性各向异性。与已发表的岩相学观察结果一致，这些微裂纹显着有助于原生碳氢化合物的迁移，特别是水平迁移。中孔隙度至高孔隙度伊利石/蒙脱石页岩的弹性各向异性弱于低孔隙度（主要是伊利石页岩）；但弹性各向异性随干酪根含量整体正向变化的趋势并未改变。
We combined acoustic velocities and anisotropy measurements with x-ray diffraction mineralogy, Rock-Eval organic geochemical analyses, vitrinite reflectance, and scanning electron microscope observations on 69 cores of hydrocarbon source rocks collected from eight sedimentary basins. The velocity data indicate the lamellar distribution of solid organic matter (kerogen) in compacted black shales and show a strong correlation between their elastic anisotropy and organic richness. The experimental results are consistent with the two-component anisotropic model of black shales with a continuous kerogen network in both bedding-parallel and bedding-normal directions beginning from relatively low TOC values. The strong elastic anisotropy of tight, thermally mature source rocks i further enhanced by overpressure-induced bedding-subparallel microcrack development during the main stage of hydrocarbon (HC) generation and primary migration at R0 greater than 0.75%. In agreement with published petrographic observations, these microcracks significantly aid primary HC migration, particularly horizontally. Elastic anisotropy of medium- to high-porosity illite/smectite shales is weaker than in lower porosity, predominantly illite shales; however, the overall positive trend of elastic anisotropy with kerogen content remains unchanged.