CAJ | 학술논문

对渭河盆地固市凹陷新近系张家坡组地质环境的研究表明，该地区沉积速率较快，沉积厚度大，平均地层温度处于48.09~78.24℃之间，水介质的矿化度及PH值适宜，有利于生物气的形成。对固市凹陷的地热水井进行天然气样品采集并送样分析，其组分特征表现出极高的CH4含量，重烃极少，δ13C1的值均小于-60‰，证实该地区的天然气为生物气成因。对张家坡组气源岩的分析结果表明，该组有机碳的平均含量为0.46%，氯仿沥青“A”的平均含量为0.041%，有机质类型多为Ⅱ1型，镜质体反射率（Ro）平均值为0.56%，处于以生物化学作用为主的生物—热催化过渡阶段。通过类比发现，该区和著名的柴达木三湖地区生物气田具有相似的生气条件，通过计算证明该区具有一定的生物气勘探前景。
대위하분지고시요함신근계장가파조지질배경적연구표명，해지구침적속솔교쾌，침적후도대，평균지층온도처우48.09~78.24℃지간，수개질적광화도급PH치괄의，유리우생물기적형성。대고시요함적지열수정진행천연기양품채집병송양분석，기조분특정표현출겁고적CH4함량，중경겁소，δ13C1적치균소우-60‰，증실해지구적천연기위생물기성인。대장가파조기원암적분석결과표명，해조유궤탄적평균함량위0.46%，록방력청“A”적평균함량위0.041%，유궤질류형다위Ⅱ1형，경질체반사솔（Ro）평균치위0.56%，처우이생물화학작용위주적생물—열최화과도계단。통과류비발현，해구화저명적시체목삼호지구생물기전구유상사적생기조건，통과계산증명해구구유일정적생물기감탐전경。
Researches on geological environment of Neogene Zhangjiapo Formation in Gushi depression of Weihe basin show that the conditions of high deposition rate,thick deposition,average formation temperature between 48.09℃to 78.24℃, proper salinity and optimum Ph values of water media are favorable for the generation of biogenic gas. The analytical result of water-soluble gas samples from geothermal wells show that the content of CH4 is extremely high, heavy hydrocarbon is rare, andδ13C1 values are less than-60‰. It is thus concluded that the water-soluble gas in this area is biogenic gas. The analysis of Zhangjiapo Formation source rock shows that the average values of organic carbon and chloroform bitumen"A"are 0.46%and 0.041%, respectively. The type of organic matter isⅡ1 and the mean value of Ro is 0.56%, belonging to biochemical to thermal catalytic transitional stage. The biogenic gas formation condition of Gushi depression is identical to that of Sanhu area which is the famous biogenic gas field. Calculation shows that there exists certain exploration prospect of biological gas in this area.