ABSTRACT: Recent gas exploration progress in Tarim Basin, China
Jia, Chengzao , Tarim Petroleum E&D Bureau, CNPC, Korla, China
Since 1998, CNPC has made significant discoveries in gas explorations in Tarim Basin, and found Kela 2, Yinan 2, Dabei 1 and Tuziluoke gas fields in Kuche depression.
The Kela 2 gas field is an anticlinal gas field with the proven gas reserves of 201 billion cubic meters, gas-bearing area of 40 sq km, gas column height of 410m, average net pay of 135m, sandstone's average porosity of 14%, average permeability of 10-100x10-3um2, depth interval of 3500-3950m, pressure coefficient of 2.0 and methane content of more than 95%. The productive reservoir is Cretaceous sandstone and the seal is the salty lower Tertiary. The production was 1,000,000m3/d in testing.
Kuche depression is a Mesozoic-Cenozoic foreland basin. The major source rocks are Triassic and Jurassic coal beds and dark mudstones with Ro of 0.7-1.6%. The 300-400m thick red sandstones of lower Cretaceous are the major reservoirs with porosity of 12-20%. The salty lower Tertiary is the regional seal.
Kuche depression was formed into a complex overthrust-related nappe in late Tertiary with three rows of structures which have sound conditions for gas charging. Up to now, CNPC has found and proved 12 gas fields in Tarim Basin, with proved gas reserves of 450 billion cubic meters and probable plus possible gas reserves of 400 billion cubic meters. Kuche depression may become one of the most important gas regions in China, with a gas resources of 2.23 trillion cubic meters.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia