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实验观察资料和理论计算结果表明,甲烷在地壳高达800℃和>10kbar的温压条件下是稳定的。这样的温压条件相当于地下35～40km的地壳深部条件。甲烷在含石墨的副变质岩中非常稳定。根据形成石英脉所需流体的体积,从一个岩墙系统或一个变质地体中主流区估计的地壳深部甲烷的通量很大,通常为几十到几百Tcf(3～30×10~(11)m~3)。地壳生成的甲烷通过相分离或分离的气相向上浮动、聚集,但是可能会伴有大量的二氧化碳和氮。形成天然气资源聚集所需的甲烷通量很难估计。在高温条件下非石墨化岩石中的地壳甲烷经氧化而消耗。为了钻探和开采地壳成因的甲烷资源,需要用特殊方法从化学方面确定其存在和最终评估其聚集量。
Experimental observations and theoretical calculations show that methane is stable at temperatures up to 800 ° C and> 10 kbar in the crust. This temperature and pressure condition is equivalent to the deep underground conditions of 35 ~ 40km underground. Methane is very stable in graphite-bearing accessory metamorphic rocks. Based on the volume of fluid required to form a quartz vein, the flux of methane in the deep crust, estimated from a dyke wall system or a mainstream in a metamorphic terrain, is typically large, typically tens to hundreds of Tcf (3 to 30 × 10 ~ 11) m ~ 3). Methane produced in the crust floats up and separates by gas phase separation or separation, but may be accompanied by large amounts of carbon dioxide and nitrogen. The methane flux required to create a natural gas resource pool is hard to estimate. The crust methane in non-graphitized rocks is consumed by oxidation at high temperatures. In order to drill and exploit crustal methane resources, special methods are needed to determine their existence chemically and to ultimately assess their accumulation.