Research On The Internal Structure Of Pu Bei3rd And4th Oil Reservoir

Pubei oilfield is the main oil reservoir of Da Qing oilfield，and the water cut is very high.To maintain oil production，water cut and production decreasing is needed to control. Aimingat this question. We do research on the internal structure of Pu Bei3rd and4th oil reservoirand get a series of achievements.Firstly， we finish the space structure analysis of underwater distributaries river waysand of Pu Bei oilfield thin sandstone oil reservoir with reservoir structure analysis. Then，we do the comprehensive research on the space distribution structure and production zone ofinterlayer. Further more， with different scale of geology and physical geologicalinformation， we do research on the internal， interlamination sacrificial and microcosmicinhomogeneous structure analysis and evaluation of underwater distributaries river way.The results show that a portion of underwater distributaries river way sand is a dependentsix-level structure unit，and another portion is composed of multi-six level in lengthways andlandscape orientation connection.The interlayer thickness of underwater distributaries riverway sand sedimentation units is thin， frequency is low， the distribution range is limited，most of them are distributed in spot， less than a well gap， minority can achieve two wellgap， few can get three well gap. As a whole， the interlayer is distributed randomly. Theinhomogeneity of Pu Bei underwater distributaries river way sand is medium~weak，and theinhomogeneity of plane is medium~strong. The resistance place of embedded single factorsand is residue oil enrichment place. Moreover， when underwater distributaries river waysand is injected and produced， above the unstable interlayer of underwater distributariesriver way sand is also residue oil enrichment place.On the foundation of the research， we combine certain modeling and randommodeling， focusing on the description of interlayer space feature， and finish the geologymodeling of reservoir structure， establishing the fine structure modeling and reservoirparameter modeling of underwater distributaries river way sand. Then we combine thereservoir space structure research and production dynamic information， developing therelationship between reservoir space structure and residue oil. At last， according to thecharacteristics of internal structure of underwater distributaries river way sand and thedistribution characteristics of residue oil， based on the difference of distributioncharacteristics and internal structure， we propose the improving method of underwater distributaries river way sand.