Abstract: Wen-23 fault block is a horst fault block in the middle and north parts of wenliu structure in the central swell of Dongpu Depression. Sha-4 gas reservoir is an inclined nose-like structure in the south. The fault block results from the pull from the near east to the west and the thrust to the east as well as the right spin and translation compound stress, thus forming the existing horst structure pattern broken up by faults. wendong and wenxi faults not only are the boundaries of the east, the north and the west,but also control the distribution of gas and water in the fault block.

Key words: Fault block, Structure, Evolution, Distribution of oily gas and water