Abstract:

The lithologic trap is one of main relay exploration domains of Shengbei Depression in Turpanharmy Basin and apractical domain for reserve increasing too. At the beginning of lithologic traps exploration in Shengbei Depression,it is necessary to systematically analyse the basic petroleum accumulation conditions of the Depression to specify the potential exploration zones of lithologic traps clearly.There are hydrocarbon source rocks in Shuixigou Group of Lower-Middle Jurassic and Qiketai mudstone formation of lacustrine facies,so the hydrocarbon source condition is good and hydrocarbon resources are rich in this depression;there are 7 reservoir-seal assemblages in Jurassic and above sequences.Oil reservoirs mainly are structure,lithologic-structure type of middle Jurassic,shallow secondary reservoir of upper Jurassic and Cretaceous. Petroleum accumulation is mainly in Yanshan period and Himalaya period. With the total situation of the present exploration of structural hydrocarbon reservoirs, the main exploration direction is to take lithologic trap identification,preference, description and evaluation to find structural hydrocarbon reservoirs surrounding the palaeostructure background.The east slope of Pubei,the north slope of Putaogou and the Shengbei structure zone situated at the cross position of north and south sedimentary source in the middle of the Depression,are favorable exploration zones of lithologic traps at present time.

Key words: southwestern Tarim, merging processing, relative preserved amplitude, reservoir prediction