Print this pagePetroleum Geology and Exploration of Tarim Basin, China
Di-Gang Liang and Cheng-Zao Jia
Since 1989 CNPC has carried on large-scale oil and gas exploration and geological research in Tarim Basin of Xinjiang Province, China. Twelve thousand km 2-D seismic, 4500 km2 3-D seismic, and 200 exploratory wells have been completed; 95 wells yield commercial oil or gas flows. At this time, eight oil/gas fields have been discovered; they include Lunnan, Yaha, and Tazhong No. 4, having proved 2.7x108t of oil and 109.2x109m3 of gas in place. Two million six hundred thousand tons of crude oil was yielded in 1995 and 5x106t crude oil will be produced in 1997.
The facies of discovered oil-gas pools in Tarim Basin are complex: there are condensate gas pools, volatile oil pools, normal oil pools, and some heavy oil pools. Structural traps form 80% of oil-gas pools. Oil-gases are mainly reservoired in sandstone beds. The burial depths of oil-gas pools range mainly from 4000 to 5500 m. Oil and condensate gas occupy 60% and 40% of proved reserves respectively. Oil-gas pools are mainly distributed in the Mesozoic-Cenozoic group, in which Tertiary occupies 50%, Triassic occupies 30% and Carboniferous occupies 20%.
Tarim Basin is a large overlapped composite basin, composed of Paleozoic cratonic basins and Mesozoic-Cenozoic foreland basins. Paleozoic and Mesozoic-Cenozoic oil-gas pools have different distribution character. Paleozoic oil-gas accumulations are controlled by cratonic paleo-uplifts and slopes. Mesozoic-Cenozoic oil-gas accumulations are controlled by foredeep uplifts and imbricate thrust structures of foreland thrust belts.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California