Abstract:

There are several secondary uplifts in the Jiyang Depression.The uplif tsare overlaped by the Shahejie Formation and the formations younger than that.The total area of high uplift on the binch-out line of the first member of the Shahejie Formation is greater than 3000 km², and the buried depth generallyless than 1400 m.Now oil and gas have been found in the overlap beds ofsome uplifts.The uplifts can be divided into two species according to their base mentrocks:the Yihezhuang type is dominated by Lower Paleozoic carbonate rocks and the Linfanjia type consists of sandstones and mudstones of the Mesozoicand Kongdian Formation.The paleotopography of the former ones undulated strongly, while the later ones were relatively gentle, as a result, the shapes and occurrences of the sandbodies in the overlap beds were different,thus forming different type pools.1.The Yihezhuang type:Oil-bearing sandstones in the overlap beds distribute around the tops of the uplifts and form stratigraphic-overlap pools.In the lower part of the uplifts, structural-lithological and structure draping pools mayform in the upper parts of secondary high points on the survival mounts ofthe basement rocks.2.The Linfanjia type:sandbodies in the overlap beds are generally wide-gentle lens, they often form stratigraphic-lithological pools.