A Systematic Sedimentary Study Of The Third Member Of Palaeogene Shahejie Formation In Guan 15-2 Block Of Wangguantun Area, Huanghua Depression

Wangguantun oilfield is in Wangguantun, county of Cangxian, Hebei Province. Its regional tectonic zone located in the west of Kongdong fault of Kongdian tectonic belt, which is in the south part of Huanghua depression. This thesis targeted the Guan 15-2 block at Wangguantun and took the third member of Shahejie Formation as research object. Some theories and technologies such as Sedimentology, high resolution sequence stratigraphy, mineral petrology, Geophysics, Petroleum Geology were applied as well as a plenty data of drill core, well drilling, bore log and seism. Depend on the former research and a core of"high resolution sequence stratigraphy --- depositional system--- lithofacies paleographic", the sedimentary facie characters of the third member of Shahejie formation in Guan 15-2 block were systematic researched and some results and new cognitions came out as below:1) Theories and methods of high resolution sequence stratigraphy which took Cross base-level cycles as guiding ideology were integrated with the data of seism, drill core, well drilling and bore log. The third member of Shahejie formation in Guan 15-2 block was analyzed by a detailed high resolution sequence stratigraphy and classified by one super-long-period cycle sequence, three long-period cycles LSC1,LSC2,LSC3). Based on the existed stratigraphy subdivision methods of the third member of Shahejie formation in Guan 15-2 block, the high resolution sequence stratigraphic features and structures of target area were systematically studied and a high resolution sequence strata framework was found with long-period cycle units.2) Combining the sedimentary facie marks and previous research results, a systematic sedimentary facie division was done at the third member of Shahejia formation in Guan 15-2 block. Three sedimentary facies of lake delta, sublacustrine fan and lacustrine were classified. Every sedimentary facies could be divided into different sub-facies and micro-facies. A sedimentary pattern which accorded with the local geological conditions of study area was modeled.3) Depends on the main mapping units with long-period cycle, three sequence-lithofacies paleographic maps with different period (LSC1-LSC3) were compiled respectively. Overall, there was a process of lake water deepened gradually during the sedimentary period from LSC1 to LSC3, and the delta front back to the direction of NE. The lake water achieved super-long-period maximum flooding during LSC3 deposit period. Sedimentation period LSC1, it mainly developed lake delta and lacustrine sediment,delta front sand shows a North-east-South-west show long banded cloth,delta front sand bodies are surrounded by shallow lake mud, sedimentation period LSC2, delta front sand bodies retreated to the NE direction obviously,shallow lake sand bar scattered in front of the delta front sand bodies, lake water is relatively deeper than that of the sedimentation period LSC1, it developed mouth bar and distal bar microfacies types in local area. Sedimentation period LSC3, delta front lobate sand bodies retreated to the NE direction continued,it developed sublacustrine fan and bathile subfacies in front of the delta front sand bodies,at the same time, lake water became further darken than that of sedimentation period LSC2, lake water reached the maximum flooding of the super-long-period cycle...