摘要
三湖地区第四系生物气在地下运聚的相态以游离气为主,约占生气量的70%以上,为该区直接形成游离相生物气藏提供了物质基础。生物气在地下的聚集成藏主要受控于同生圈闭,因此只有在下更新统K1同生背斜定型(距今1.35Ma)后排出和析出的游离气量才是可供聚集的有效排气量。压实水动力和浮力是游离气垂向运聚成藏的直接动力,可提供9.72×108m3/km2的有效气量;下渗水动力是含气水流侧向运移的动力,可提供1.08×108m3/km2的有效气量。根据运聚动力、运聚数量和聚集样式的分析,三湖地区第四系生物气可概括为"自生自储、以近源垂向运聚为主、受同生圈闭控制"的成藏模式。在此基础上预测该区第四系生物气的地质资源量为11210×108m3,三级储量为5604×108m3。
The migration and accumulation phase of biogas in the Quaternary of Sanhu area in Qaidam Basin is mainly free-phase gas accounted for more than 70% in total, which can provide the material base for the accumulation of free-phase biogas in this area. Biogas pools underground are mostly controlled by contemporaneous trap. So, the free phase gas expelled and released after shaping of the syn-sedimentary anticline in the Lower Pleistocene（1.35 Ma before present）is the effective expulsion gas quantity. The compaction hydrodynamic and buoyancy are the direct motivation for the vertical movement of the free-phase gas and can provide 9.72 ×10^8m^3/km^2 of effective expulsion gas quantity. The downward infiltration hydrodynamic is the impetus of lateral migration of the contained gas current and can offer 1.08 ×10^8m^3/km^2 of effective expulsion gas quantity. According to the.dynamic, quantity and style features of free-phase gas migration and accumulation, the Quaternary gas accumulation model can be summarized as ＂self-generation and self-accumulation, dominated by vertical migration-accumulation near the source and controlled by the contemporaneous trap＂. The geologic resources of biogas count up 11 210 ×10^8m^3 and the possible reserves are 5604×10^8m^3 in the Quaternary of Sanhu area.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2009年第6期809-815,共7页
Acta Petrolei Sinica
关键词
柴达木盆地
三湖地区
第四系
游离相生物气
同生圈闭
有效排气量
成藏模式
Qaidam Basin
Sanhu area
Quaternary
free-phase biogas
contemporaneous trap
effective expulsion gas quantity
gas pool-forming model
