永北地区砂砾岩体成岩作用及次生孔隙成因

通过对岩芯、岩石薄片的观察，运用扫描电镜、X衍射等分析方法，对永北地区沙三、四段砂砾岩储层进行了成岩作用研究，揭示了成岩作用对永北地区砂砾岩体储层物性的影响。认为胶结作用是储层物性变差的主要因素，胶结损孔率平均值高达43.95％；压实作用一方面导致储层原生孔隙减小，储层物性变差，另一方面强烈压实产生的大量粒内压裂缝，对砂砾岩储层物性具有一定的优化作用，但以损失原生孔隙为主，压实损孔率平均值为25.29％；溶蚀作用形成的次生孔隙为该储层主要的储集空间。有机质热演化、淋滤作用和异常高压所导致的溶蚀作用是该区次生孔隙形成的主要原因。

Application of Natural Gas in Distributed Energy Systems

In order to understand the influence of pore evolution and diagenesis on sandstone and conglomerate reservoir petrophysical property of the third and fourth members of shahejie formation in yongbei area，reservoir rock property and diagenesis are studied by using the methods of core and rock tine section observation，electron microscope scanning and Xdiffraction analysis.It is revealed that cementation destroys the reservoir property and dissolution improves it.Compaction result in primary pore decreasing，on the other hand，high pressure result in mineral grain breaking，so physical properties of reservoirs are improved.The loss ratio of porosity from the cementation and filling is about 43.95%，and that from compaction is about 25.29%.The secondary pores account for a great proportion in the Es3-Es4 reservoirs.The mechanism of genesis includes thermal evolution of organic matter，experiment indicates that the thermal degradation makes kerogen produce a large amount of organic acid before it goes into the oil generation windows，eluviations at unconformities or fracture zones produce weathering crust secondary pores，the fluid thermal cycle convection leads to the formation of secondary pores.