科学技术与工程
科學技術與工程
과학기술여공정
Science Technology and Engineering
2015年
32期
121-128
,共8页
何瑜%张敏%陈小慧%龚建明%李永红%王伟超%雷天柱
何瑜%張敏%陳小慧%龔建明%李永紅%王偉超%雷天柱
하유%장민%진소혜%공건명%리영홍%왕위초%뢰천주
煤系烃源岩%饱和烃%地球化学特征%木里冻土区%天然气水合物
煤繫烴源巖%飽和烴%地毬化學特徵%木裏凍土區%天然氣水閤物
매계경원암%포화경%지구화학특정%목리동토구%천연기수합물
coal-measure source rocks%saturated hydrocarbon%geochemical characteristics%Muli permafrost%natural gas hydrate
随着天然气水合物的发现,祁连山冻土区成为勘探研究重点区块。通过系统的野外露头采样,在进行有机碳测试、镜质体反射率等常规地球化学分析的基础上,运用气相色谱-质谱分析技术,探讨了研究区烃源岩有机质的母质来源、沉积环境以及热演化程度。研究结果表明:研究区样品热演化程度均较高,主要处于高成熟阶段,且C25四环萜烷可能是研究区潜在的有机质高演化阶段特征性标志物。样品母质来源为陆源高等植物与低等水生生物的双重贡献。泥岩姥植比小于1.0、伽马蜡烷值小于0.2,形成于淡水还原环境;而煤样姥植比大于1.0,主要形成于偏氧化环境,以高等植物贡献为主。结合研究地区的沉积相,石炭系、二叠系主要为海陆交互相,侏罗系为湖沼相沉积,煤样可溶烃的生物标志物同样反映这一变化特征。
隨著天然氣水閤物的髮現,祁連山凍土區成為勘探研究重點區塊。通過繫統的野外露頭採樣,在進行有機碳測試、鏡質體反射率等常規地毬化學分析的基礎上,運用氣相色譜-質譜分析技術,探討瞭研究區烴源巖有機質的母質來源、沉積環境以及熱縯化程度。研究結果錶明:研究區樣品熱縯化程度均較高,主要處于高成熟階段,且C25四環萜烷可能是研究區潛在的有機質高縯化階段特徵性標誌物。樣品母質來源為陸源高等植物與低等水生生物的雙重貢獻。泥巖姥植比小于1.0、伽馬蠟烷值小于0.2,形成于淡水還原環境;而煤樣姥植比大于1.0,主要形成于偏氧化環境,以高等植物貢獻為主。結閤研究地區的沉積相,石炭繫、二疊繫主要為海陸交互相,侏囉繫為湖沼相沉積,煤樣可溶烴的生物標誌物同樣反映這一變化特徵。
수착천연기수합물적발현,기련산동토구성위감탐연구중점구괴。통과계통적야외로두채양,재진행유궤탄측시、경질체반사솔등상규지구화학분석적기출상,운용기상색보-질보분석기술,탐토료연구구경원암유궤질적모질래원、침적배경이급열연화정도。연구결과표명:연구구양품열연화정도균교고,주요처우고성숙계단,차C25사배첩완가능시연구구잠재적유궤질고연화계단특정성표지물。양품모질래원위륙원고등식물여저등수생생물적쌍중공헌。니암모식비소우1.0、가마사완치소우0.2,형성우담수환원배경;이매양모식비대우1.0,주요형성우편양화배경,이고등식물공헌위주。결합연구지구적침적상,석탄계、이첩계주요위해륙교호상,주라계위호소상침적,매양가용경적생물표지물동양반영저일변화특정。
Qilian Mountain permafrost has been the main exploration region since samples of gas hydrate have been drilled.Based on the analysis of organic carbon content and vitrinite reflectance measurement, combined with GC-MS, the organic source, depositional environment and thermal maturity of hydrocarbon source rocks were sys-tematically discussed.The results show that samples of the study area stay in a high mature stage during the thermal evolution.The C25 tetracyclic terpane may be an indicator which reflects organic matters with high maturity in the study area.Lower aquatic organisms mixed with higher terrigenous plants are proven to be the organic material of hydrocarbon source rocks.The Pr/Ph value ( <1 ) and gammacerane/C30 hopane value ( <0.2 ) of coal-measure mudstones indicate that source rocks are developed in a fresh water-reductive environment.High Pr/Ph ratio illus-trates these coals, derived from higher terrigenous plants, formed in oxygenated conditions.The coals in the Car-boniferous and Permian are deposited in a marine-terrestrial environment.However, coal in the Jurassic mainly formed in lacustrine-swamp facies.Biomark analysis of soluble hydrocarbon in coals, combined with the sedimenta-ry facies of study area, was illustrated the same characteristics.