CAJ | 학술논문

埋藏史、受热史和有机质成熟史(简称“三史”)模拟技术已广泛应用于油气地质研究,但其在煤和煤层气地质领域则应用较少.根据实测煤的镜质组最大反射率、古地温梯度和地层残余厚度等资料,运用 Petromod 1D模拟软件对贵州织纳煤田水公河向斜上二叠统8煤层“三史”演化过程进行研究.结果显示,水公河向斜地质演化史可分为3个阶段:第1阶段从晚二叠世至侏罗纪末,煤层埋深增加,最大至5925~5959 m,地温梯度为2.91/hm℃,受深成变质作用影响,煤级从褐煤演化至焦煤阶段;第2阶段从侏罗纪末至白垩纪末,受燕山运动影响,煤层埋深降低,地温梯度为3.29~3.46/hm℃,区域岩浆热变质作用使煤级从焦煤演化至无烟煤阶段;第3阶段从白垩纪末至今,地层少量沉积后发生抬升作用,地温梯度为2.78℃/hm,煤化作用基本停止.总之,深成变质作用是向斜煤层气生成的主要影响原因,距今230~170 Ma是煤有机质生烃的关键时期.
매장사、수열사화유궤질성숙사(간칭“삼사”)모의기술이엄범응용우유기지질연구,단기재매화매층기지질영역칙응용교소.근거실측매적경질조최대반사솔、고지온제도화지층잔여후도등자료,운용 Petromod 1D모의연건대귀주직납매전수공하향사상이첩통8매층“삼사”연화과정진행연구.결과현시,수공하향사지질연화사가분위3개계단:제1계단종만이첩세지주라기말,매층매심증가,최대지5925~5959 m,지온제도위2.91/hm℃,수심성변질작용영향,매급종갈매연화지초매계단;제2계단종주라기말지백성기말,수연산운동영향,매층매심강저,지온제도위3.29~3.46/hm℃,구역암장열변질작용사매급종초매연화지무연매계단;제3계단종백성기말지금,지층소량침적후발생태승작용,지온제도위2.78℃/hm,매화작용기본정지.총지,심성변질작용시향사매층기생성적주요영향원인,거금230~170 Ma시매유궤질생경적관건시기.
Simulation technology in burial history, thermal history and maturation of organic matter (three histories for short) has been widely applied to study petroleum geology, but its application is less in the field of coal and CBM. Based on the measured maximum vitrinite reflectance of coal, geothermal gradient and stratigraphic residual thickness, evolution process of“three histories”for coal seam No.8 in upper Permian of Shuigonghe syncline was studied using Petromod 1D simulation software. The results show that geological evolution history of Shuigonghe Syncline can be divided into three stages. At the first stage, from Late Permian to Jurassic, the burial depth of coal beds increased to the maximum of 5 925~5 959 m. Geothermal gradient is 2.91 /℃hm. Coal rank evoluted from lignite to coke due to deep burial metamorphism. At the second stage, from Late Jurassic to Late Cretaceous, the burial depth of coal bed decreased during Yanshan movement and geothermal gradient was from 3.29 /℃hm to 3.46℃hm. Due to regional magmatic metamorphism, coal rank evoluted from coking coal to anthracite. The third stage is from the Late Cretaceous till now, coal bed firstly was deposited and then uplifted. Geothermal gradient is 2.78/℃hm. Coalification has almost stopped in the last stage. In a word, deep burial metamorphism is one of the main factors influencing CBM generation, and the time from 230 Ma to 170 Ma is the key time for CBM maturity./