DISPLACEMENT CALCULATION FOR STRIKE-SLIP FAULT BASED ON CORRELATION OF STRATA THICKNESS TENDENCY: A CASE FROM THE LIAODONG FAULT, OFFSHORE BOHAI BAY

The Liaodong fault, located in the northeast Bohai Bay Basin, is a straight strike-slip fault formed in Late Eocene. Facts prove that the slipping of fault has a tremendous impact on the distribution of oil and gas in the region. However, the displacement of the strike-slip fault is always difficult to calculate in offshore areas for quantitative fault analysis due to various limitations. It also restricts detailed analysis of reservoir-forming conditions. Based upon the interpretation of structural features from the newly merged 3D seismic data, the Liaodong fault could be subdivided into three sections, i.e. the northern, middle, and southern sections. A new method was then adopted to analyze the similarity of strata-thickness variations trend on the two walls of the fault with the correlation coefficient. Some displaced sedimentary bodies are restored and used to check the calculated displacement with seismic attributes. The results are dependable, upon which the displacements of the Liaodong strike-slip fault in different periods and sections are acquired quantitatively. Combined with drilling data, it is confirmed that the strike-slip fault in northern Liaodong, where occur large displacement, has good fault sealing ability. Similar to the north, traps in the south are also favorable for hydrocarbon accumulation, due to good fault sealing conditions.