Abstract: Grooves are extremely developed in No.5 Member of Majiagou formation of the Lower Ordovician in Jingbian gas reservoir. In the past, the grooves were studied mainly by drilling, seismic waveform and compensation relationship between upper and lower layer of paleo-weathering crust for qualitative and semi-quantitative identification. The large scale grooves could be identified easily, while the small scale (second-tertiary class) cross-well grooves were difficult to identify. This paper verifies the existence of such grooves boundary by using dynamic methods such as well test analysis and production transient analysis, providing basis for fine depicting the geologic model. Combined with drilling constraints, seismic waveform and arc length parameters, there exist 16 primary grooves, 83 secondary grooves and 206 tertiary grooves in Lower Ordovician gas reservoir in this area.

Key words: dynamic method, groove boundary, well test analysis, production transient analysis