Print this pageAbstract: Evaluation of Sichuan Basin in China
Joe G. Zhou
Sichuan basin lies in the central-south China, in a compression tectonic regime, with an area of approximately 180,000 km2. It is a prolific basin with a upside resource potential of gas 5045.38 billion m3, and oil 3.56 billion tons. By year-end 1993, the possible geological reserve of gas was 676.136 billion m3, and oil 0.14 billion tons; totally about 140 billion m3 of gas and about 3.5 million tons of oil have been produced to date; thus, there will be 4,229 billion m3 gas yet to find.
During about 4O years' exploration (1950 to 1990), 81 gas/oil fields, including 245 gas pools and 15 oil pools, had been discovered through 2357 wells (total footage 5,804,094 m). 257 surface structures and 189 buried structures (by 91,136 km seismic) had been found in the basin, of which 172 structures had been drilled. The basin contains 21 gas/oil reservoirs of commercial value, distributed from Sinian to Jurassic, in the depths ranging from 7,157 m (well-Guanji) to hundreds of meters.
It is evident that the gas and water distribution is not controlled by regional structures or local anticlinal structure but depends on the local development of permeability and fracture porosity in reservoir objectives. Each local occurrence of permeability and porosity functions as a trap for both gas and water, and new gas reservoirs are continuously being found on anticlinal gas fields that have been on production for years.
AAPG Search and Discovery Article #90952©1996 AAPG Rocky Mountain Section Meeting, Billings, Montana