The Potential Evaluation Of Yingtai Fault Depression Deep Resources And The Division Of Favorable Area

Since the breakthrough of deep natural gas exploration was made in 2007, Yingtai fault depression has become one of the key blocks of deep natural gas exploration in southern Songliao Basin. And the four prospecting shafts which are deployed on Yingtai fault depression have successfully obtained commercial gas flow. This is to say, it’s of great significance in future natural gas exploration to study intensively on the the hydrocarbon generation potential of hydrocarbon from deep source rocks and assess resource precisely. In this paper, three sets of hydrocarbon source rocks in Yingtai fault depression are chosen to be assessed and evaluated quantitatively as well as qualitatively and compared the gas source correlation, which is expected to play a guiding role in future work of deep natural gas exploration of Yingtai fault depression.The qualitative evaluation results of hydrocarbon source rocks show that the source rocks of Yingtai fault depression deep Denglouku Formation is mainly marked as the moderate-good source rocks, some are leveled as very good source rocks; most of the kerogen are type Ⅱ2. the source rocks of Yingcheng Formation is mainly marked as the good-very good source rocks; most of the kerogen are type Ⅱ1. The source rocks of Shahezi Formation is mainly marked as the moderate-good source rocks; most of the kerogen are type Ⅱ1-Ⅱ2. By the method of logging geochemistry, we calculated the TOC abundance and characterized the Toc contour map of Denglouku, Yingcheng and Shahezi Formation.All the three sets of source rocks are in high-mature and post-mature stage, whose oil generation peak is at 1900m and gas generating peak is in the range of 2100m～2900m.The quantitative evaluation results of hydrocarbon source rocks show that Yingtai fault Denglouku Formation has totally generated 4980×109m3 gas, whose amount of resources is calculated to 49.8-249×109m3 considering the migration accumulation factor as 1 to 5 percents. Yingcheng Formation has totally generated 85288x 109m3 gas, whose amount of resources is calculated to 852.88-4264.4×109m3 considering the migration accumulation factor as 1 to 5 percents. Shahezi Formation has totally generated 27546×109m3 gas, whose amount of resources is calculated to 275.46～1377.3×109m3 considering the migration accumulation factor as 1 to 5 percents.Gas source comparison shows that the natural gas generated in Denglouku Formation and Yingcheng Formation source rocks mainly supplies the clastic reservoir rocks of themselves. The natural gas generated in Shahezi Formation source rock, however, supplies the volcanic layer reservoir of Yingchengzu Formation zone 1.The favorable area of Denglouku Formation is in the northern hydrocarbon generation area with high intensity value; the favorable area of Yingcheng Formation is basically distributed through out the region; the favorable area of Shahezi Formation is in the overlapping area of Yngchengzu Formation zone 1 volcanic rock reservoir and the high intensity area of the middle-northern hydrocarbon generation area.