| PDF: | |
| Time: | 2006 |
| Journal: | Journal of Jilin University (Earth Science Edition) |
| Volumn: | 36 |
| Issue: | 2 |
| Pages: | 207-214 |
| Type: | Other |
| Author: | Zhenhua Guo,Pujun Wang,Changhai Yin,Yulong Huang |
Abstract: | The Mesozoic volcanic rocks are the most important gas reservoir in the northern Songliao Basin. 5 lithofacies and 15 subfacies have been recognized in the volcanics. The best reservoirs were generally found in three of the fifteen subfacies including pyroclastic bearing lava flow（Ⅱ3）, upper effusive（Ⅲ3） and inner extrusive（Ⅳ1）subfacies. The corresponding logging characteristics are as follows: the Ⅱ3 is characterized by high value of Gama Ray (GR) with low amplitude dentiform outline, and by mediahigh value of Dual Lateral Logging of Resistivity (DLL) with low frequency and low amplitude dentiform outline; the Ⅲ3 is high in GR with low amplitude dentiform shape, DLL value of the Ⅲ3 is mediamedia high and with shapes of finger or hill figure; the Ⅳ1 shows high value of GR with media amplitude dentiform shape, its DLL is media highhigh value with media amplitude dentiform shape. Besides, undergroundexplosive breccia facies（Ⅰ3）and outer extrusive facies（Ⅳ3）can also be good reservoirs. Gas can cause DLL of the reservoir volcanics increasing markedly but water does the contrary. The DLL of dry volcanic rocks indicates facies and rock type dependent, in the sequence of volcanogenitic sedimentary facies＜extrusive facies＜explosive facies＜volcanic vent facies＜effusive facies; tuff＜lava. |