CAJ | 학술논문

南堡凹陷2号构造带天然气成因研究薄弱，采用地质地球化学途径对深、浅层天然气特征及其形成机制进行了研究。分析表明，该构造带天然气以烃类气体为主，非烃组分以 CO2、N2和 H2 S 为主，且主要集中在深部潜山天然气中；天然气的干燥系数（C1／C1－5）为0.68～0.94，具有典型的湿气特征，其中南堡280断块天然气相对偏干；天然气碳同位素整体上具有正碳同位素系列趋势，少量样品出现碳同位素部分倒转。依据母质类型和成熟度的分析，将该构造带天然气划分为3种类型：成熟阶段早期形成的混合气（东一段、馆陶组）、成熟阶段晚期形成的混合气（老堡南1断块）、高成熟阶段形成的煤型热解气（南堡280断块）。综合分析认为，第三系浅层东一段和馆陶组天然气来自于东三＋沙一段烃源岩，潜山天然气主要来源于沙三段偏腐殖型烃源岩，沿断层和不整合运移到储集层中。这个研究对南堡油田深浅层天然气勘探具有重要参考价值。
남보요함2호구조대천연기성인연구박약，채용지질지구화학도경대심、천층천연기특정급기형성궤제진행료연구。분석표명，해구조대천연기이경류기체위주，비경조분이 CO2、N2화 H2 S 위주，차주요집중재심부잠산천연기중；천연기적간조계수（C1／C1－5）위0.68～0.94，구유전형적습기특정，기중남보280단괴천연기상대편간；천연기탄동위소정체상구유정탄동위소계렬추세，소량양품출현탄동위소부분도전。의거모질류형화성숙도적분석，장해구조대천연기화분위3충류형：성숙계단조기형성적혼합기（동일단、관도조）、성숙계단만기형성적혼합기（로보남1단괴）、고성숙계단형성적매형열해기（남보280단괴）。종합분석인위，제삼계천층동일단화관도조천연기래자우동삼＋사일단경원암，잠산천연기주요래원우사삼단편부식형경원암，연단층화불정합운이도저집층중。저개연구대남보유전심천층천연기감탐구유중요삼고개치。
The origin of natural gas in No.2 structural belt of Nanpu depression is still unclear.Geological and geochemical approaches are utilized to reveal the characteristics and genetic mechanisms of deep and shallow natural gas.The results show that the components of natural gas in No.2 structural belt are dominated by hydro-carbon gas with non-hydrocarbon mainly composed of CO2 ,N2 and H2 S,which are mainly found in buried hill reservoirs.The dry coefficient of natural gas varies from 0.68 to 0.94,indicating mainly a wet gas.Carbon iso-topes of natural gas are relatively heavy,showing a tendency of normal order,but some samples display a par-tially reversed isotopic order with δ13 C3 >δ13 C4 .There are three types of natural gas in No.2 structural belt with the analysis of organic matter type and maturity:the mixture gas generated during early phase of mature stage (gas within Ed1 and Ng),the mixture gas generated during late phase of mature stage (gas within LPN1 fault block)and coal-based pyrolysis gas generated during high mature stage (gas within NP280 fault block).The comprehensive analysis indicates that the natural gas within Ed1 and Ng formations of Tertiary is mainly genera-ted from Ed3 and Es1 source rocks,while natural gas within buried hill is mainly derived from humic type organ-ic matter in Es3 Member.Faults and unconformities are the main paths for hydrocarbon migration.This research should be helpful to further exploration of deep and shallow natural gas in Nanpu depression.