| Time: | 2007 |
| Journal: | Global Geology |
| Volumn: | 26 |
| Issue: | 3 |
| Pages: | 319-325 |
| Type: | Other |
| Author: | Pujun Wang,Qijun Hou,Wanzhu Liu,Yulong Huang,Juntao Jia,Huafeng Tang |
Abstract: | The Songliao Basin is composed of two basin filling The lower part, generally being buried more then 3000m beneath the surface, consists of Late Jurassic end Early Cretaceous volcanogenic successions including Huoshiling Formation (J3h), Shahezi Formation (K1sh) and Yingcheng Formation (K1y) which were formed in the block-faulting stage. The upper part is made up of normal sedimentary sequence of Albian, to Maastrichtian stages, which was formed in the sagging episode of the basin evolution. The volcanic rocks of Yingcheng Formation contribute 87% of the reservoirs for the deep basin gases. Porosity and permeability of the reservoir volcanic rocks are fade-controlled. The best volcanic are commonly found among those subfacies including diatreme (Ⅰ1), pyroclastic bearing lava flow (Ⅱ3), upper effusive (Ⅲ3) and inner extrusive ones (Ⅳ1), with the latter two ones being the best. Commercial gases found in the volcanic reservoirs there include hydrocarbon, CO2, N2, H2S end scene noble gases. Multi-sources for those gases are concluded, i.e. a mixture of gases from coal, mudstone and abiogenic origin gases which may be mantle/magma-derived, based on composition of the natural gases trapped, the C/H isotopes of the hydrocarbon and CO2. |