PRELIMINARY STUDIES ON THE FORMATION AND THE ACCUMULATIVE REGULARITY OF THE JURASSIC SECONDARY GAS POOLS IN THE XIAOQUAN STRUCTURE

The Jurassic gas pools in the Xiaoquan Structure are the secondary gas pools controlled by effective reservoirs and fracture system with the source from the Xujiahe Fr. deep gas. The formative condition and the accumulative regularity are characterized by double seals with direct seal beds and regional covers,and the natural gas illustrates its wide distribution and multiple pools,consisting of a certain accumulative belt with "secondary" high abnormal pressure. The high productive gas belt is generally distributed on the high pressure zones and the gas pools have their own independent systems without edge and bottom water seals,attributed to pure gas pools.