Abstract: In the case of more and more serious energy crisis, along with the deepgoing petroleum & gas exploration and development, it is desired urgently for the exploring technology for fractured reservoir. The fractured reservoir is built up mainly by structural fracture, so structural fracture estimating is very important. And the tectonic stress field modeling is the most available approach for structural fracture estimating. The modeling with the elastic-plastic increment mode not only can model approximately the plastic deformation of geologic body, but also can consider the nonuniformity of the geologic body, so the modeling under the regional geologic evolution will indicate more closely the tectonic intensity. The modeling results in Dongying Formation in the eastern limb North Dagang Structural Zone show that the shearing stress distribution can accordingly indicate the petroleum assembling locations, so it is estimated that there is a meridional structural fracture developing zone in the middle of the eastern limb of the North Dagang Structural Zone, which will be the advantageous exploration target in future.

Key words: tectonic stress field, elastic-plastic increment mode, structural fracture, exploration target