Abstract:

By contrasting the 3-D seismic data of the well-tie area of Toutunhe Formation，we analyzed the stratigraphic
thickness changes and the distribution of stratigraphic pinch-out line，and researched about palaeogeomorphology characteristics
and structure unit with the method of stratigrapic thickness and seismic layer leveled. In addition，with tectonic evolution of
the cross-section and plan analysis we explored palaeogeomorphology evolution and features after transformation. Then the
analysis of the controlling role of palaeogeomorphology on deposition and lithology were made by taking into consideration
seismic attribute，sedimentary facies and downhole lithology，for the purpose of finding out the sedimentary facies and reservoir
lithological characteristics in this area. The palaeogeomorphology topography is characteristic of a combination of slope-ditchupheaval-
concave. Degree of slopes show certain effect on type of sedimentary facies，lithology and the sediments thickness.
The valley is lose sand channel，and also an important place for poly sand；modern sand body distribution is closely related
to valley spread direction. Based on the above analysis of geological characteristics and distribution of oil and gas reserve in
Chepaizi area，the authors point out the favorable zones for exploration and development.

Key words: Chepaizi Area, palaeogeomorphology, structural evolution, seismic interpretation, oil and gas distribution