Abstract:
The Upper Carboniferous shale found within the Hexi Corridor Basin group exhibits favorable physical properties,including burial depths ranging from 1200 to 3000 m and thicknesses exceeding 170 m.These shales possess a porosity of 2-4%,permeability of 0.02-0.08×10
-3 μm
2,and organic matter content averaging 3.28% TOC.The presence of Type Ⅲ kerogen,with minor amounts of Type Ⅱ2 kerogen and a high Ro of approximately 1.3%,indicates that the shale is in the early stage of oil and gas generation,making it an excellent hydrocarbon source.Furthermore,shale has a high gas content of 2-3 m
3/t in shale and 6-8 m
3/t in coal seams.The brittleness index of the rock was 70%,indicating good flexibility.The analysis of unconventional exploration targets in the Sichuan Basin suggests that the brittleness index of shale and the composition of clay minerals are crucial factors affecting unconventional oil and gas exploration.The Carboniferous shale in the Hexi Corridor,owing to its good hydrocarbon source conditions and high brittleness index,presents promising prospects for unconventional oil and gas exploration.