莺歌海盆地D1-1底辟区天然气成藏过程与分布差异  

Natural Gas Accumulation Process and Distribution Differences in D1-1 Diapir District,Yinggehai Basin

作　　者：朱建成 吴红烛[2,3] 马剑[2] 童传新 姜春艳 

机构地区：[1]中海石油(中国)有限公司湛江分公司,广东湛江524057 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]浙江省地球物理地球化学勘查院,浙江杭州310005

出　　处：《现代地质》2015年第1期54-62,共9页Geoscience

基　　金：国家科技重大专项(2011ZX05023-004-008)

摘　　要：通过对莺歌海盆地D1-1底辟区中深层高温超压带与浅层正常压力带、压力过渡带天然气的组成、碳同位素特征差异的对比分析,结合底辟活动特征,研究了天然气藏的形成过程和天然气组分的分布规律。研究结果表明:(1)D1-1底辟核部区和底辟波及区中深层天然气成藏过程有差异,主要受底辟活动影响程度的控制。底辟核部区中深层气藏的形成过程为早期成藏、后期破坏并再次充注;底辟波及区中深层气藏的形成则为早期成藏,后期改造较弱,成熟煤型原生气藏保存较好。(2)D1-1底辟核部区和底辟波及区中深层天然气组分、碳同位素分布有明显规律;随距底辟核部距离的增大,其甲烷含量升高,二氧化碳含量降低,甲烷碳同位素变轻(成熟度降低),二氧化碳碳同位素也变轻,底辟核部区富集无机成因CO2,至底辟波及区则以有机成因CO2为主。By contrast and analysis of natural gas composition and carbon isotope characteristics between high temperature and high pressure（hthp）zone of middle-deep strata,normal pressure zone and pressure transition zone of shallow strata in the central diapir district,and combined with the feature of diapiric activity,natural gas accumulation process and its composition distribution discipline are studied in this paper.The results indicate that,controlled by the intensity of diapir activity,natural gas accumulation process is much different from the D1-1 diapir core to diapir affected areas.The accumulation process at diapir cores was early accumulation,late destruction and refilling,while when it get to diapir affected areas,this phenomenon presents early accumula-tion but slight late destruction,and thus,diapir affected areas had perfectly preserved early filled mature coal-type natural gas.Furthermore,the distribution of natural gas composition and carbon isotope from diapir core to diapir affected areas is also well-regulated.With the increase of distance from diapir cores,the content of meth-ane increases and carbon dioxide decreases,and carbon isotope of both methane and carbon dioxide decrease （maturity decreases）too.Obviously,it dominantly had accumulated rich organic caused CO2 in diapir affected areas while inorganic caused CO2 in diapir cores.

关 键 词：天然气充注过程 高温超压带 D1-1底辟区 莺歌海盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]