Fault System And Its Control On Oil-water Relationship Of Development Block In Haita Basin

Haita basin is divided vertically into upper and lower sets of fault systems, the limiting strata is Damoguaihe group. The lower sets of fault have a large-scale. The upper sets of fault have a small-scale. The faults of Haita basin gone through Three strongly deformed, the period of phaseâ… was Tongbomiao-Nantun deposition time, the period was typical extensional deformation. the period of phaseâ…¡was Late Yimin group deposition time, the period was typical transtension deformation. the period of phaseâ…¢was Late Yimin and Late Qingyuangang group deposition time, the period was typical Reverse deformation.In the light of overlying relationship of ruptural deformation ,the basin of Haita develop four suit of rift system:extensive rift system in early stage,tenso shear rift system in middle period,extensive rift system in early stage and tenso shear rift system in middle period, extensive rift system in early stage tenso shear rift system in middle period and inverted rift system in late time. In the light of the coupling relationship of the stage of ruptural deformation and the crucial moment of developing oil reservoir,we think that the extensive rift system is canonic screened rift;Although extensive rift system in early stage and tenso shear rift system in middle period acts in the crucial moment of developing oil reservoir. Because they expand sectionly in territorial argillaceous rock capping formation in Nantun group and D I group,the shear-type of clay daubing develop, It has sronger seal capacility in the peak. It is not the fault of oil source,but it is canonic screened fault as before; extensive rift system in early stage tenso shear rift system in middle period and inverted rift system in late time inverted in late depositional stage of Yimin group. The active nature change the fault of the shear-type of clay daubing in early stage,which makes it become a aisle of vertical migration of oil and gas.but the active stage was later than the crucial moment of developing oil reservoir, So it is typical regulate fault. Fault traps are divided to dichotypic and six types in Haita basin. On the basis of sand layer ratio distributing regular pattern, there are typical fault traps in the north of Nan 1 section reservoir which is fault shielding reservoir of Wudong and tongbomiao section of Tanan. the middle part and south of Nan 1 section reservoir which is structure -lithology reservoir are fault traps and lithological complexing traps. There are fault complexing anticlinal traps, which are lithology- structure reservoir. Fault lateral seal affect oiliness of fault traps. On the basis of dissection of typical sealed fault, establishing quantitative relation between face of fault SGR and highest hydrocarbon column. The maximal hydrocarbon height sealed by typical reservoirs in Wudong and Tanan area and OWC can be evaluated using this quantitative relation. All evaluated hydrocarbon height is smaller than the largest amplitude detector of reservoir indicating that all the reservoir is effective. The representation which faults controls the relation of oil and water is mainly in three aspects: First one is the fault modulation effect of extension in eraly stage, transtension in metaphase and inversion in advanced stage, which caused the oil being regulated from major target formations(FM Nan 1or Tongbomiao group) to FM Nan2 or Damoguaihe group forming "complementary" distribution pattern. So the major target formations general contain water. Second one is the oil-bearing property effected by lateral fault seal.It's the oil region between OWC determined by maximal height sealed by faults and reservoir-dominating faults, and It's the water region between OWC and maximal trap line. Third is that the faulted effect generally caused major target formations missing, and the layer mainlty contain water or is dry layer. Wudong reservoirs are effected by the three factors, the north is tectonic reservoirs owning clear OWC. Three adjusting faults developed in Beizhong forming subreservoirs (Xi2, Xi4 and Xi64-64). In this area, oil-bearing property is bad in FM Nan1. Faulted effect commonly exists forming several local water region near faults. Fault barrier reservoir mainly developed in middle-West of Tanan, and oil-water distribution relation is mainly effected by lateral fault seal capacity. Every fault block owns relatively clear OWC.