CAJ | 학술논문

廊固凹陷是一个晚期构造运动强烈，具有残留盆地性质的新生代沉积盆地。多年勘探证实，浅层天然气(生物气，埋藏深度小于2 000 m)资源丰富，且发现了具一定规模的天然气藏。由于沙河阶组(Es)气源岩沉积以后发生了强烈的构造运动，使成岩早期形成的生物气难以保存下来。文章在对国内、外煤层气型生物气的地化分析数据和形成的地质条件分析的基础上，与廊固凹陷地质条件和油气分布状况相对比，结合微生物模拟实验数据，提出廊固凹陷的浅层天然气类型为生物改造气和后期式生物气，并初步阐明了其形成机制。特别是后期式生物成因气形成机制，对具有类似地质条件地区的天然气勘探，具有一定参考价值。
랑고요함시일개만기구조운동강렬，구유잔류분지성질적신생대침적분지。다년감탐증실，천층천연기(생물기，매장심도소우2 000 m)자원봉부，차발현료구일정규모적천연기장。유우사하계조(Es)기원암침적이후발생료강렬적구조운동，사성암조기형성적생물기난이보존하래。문장재대국내、외매층기형생물기적지화분석수거화형성적지질조건분석적기출상，여랑고요함지질조건화유기분포상황상대비，결합미생물모의실험수거，제출랑고요함적천층천연기류형위생물개조기화후기식생물기，병초보천명료기형성궤제。특별시후기식생물성인기형성궤제，대구유유사지질조건지구적천연기감탐，구유일정삼고개치。
Langgu Sag is a Cenozoic sedimentary basin suffered a strong tectonic movement in the late stage,being of the properties of remnent basin.Through exploration for many years it is proved that the resources of shallow gas (i.e.biogas with buried depths of less than 2 000 m) are abundant and the gas reservoirs with a certain scale have been found.The biogas origined in eodiagenesis was difficult to be preserved,because the strong tectonic movement occurred after the gas source rocks of Shaheije Formation (Es) had been deposited.On the basis of analyzing the geochemical indicators of the biogases of coal-bed gas type found at home and abroad and analyzing the geological conditions of forming these biagases,in comparison with the geological conditions and oil and gas distribution in Langgu Sag and in combination with microbial analogic experimental data,it is proposed that the types of the shallow gas in Langgu Sag should be biogenic transform gas and telogenetic biogas.Their origin mechanisms are primarily expounded in the paper;especially,the origin mechanism of the telogenetic biogas has a certain value for reference in natural gas exploration at these regions with the same geological conditions.