Research On Subdivision Control Fracturing Technology Of Thin Interbedded Reservoir

The thin poor tabulated reservoirs and untabulated reservoirs of Changyuan internal oil field have become the main targets of adjustment and tapping for high-yield and stable production in oilfields.Due to their relatively poor lithology,physical properties and oil-bearing properties,the fracturing reconstruction should be implemented for the properly developed.Limited entry fracturing is always an irreplaceable completion technology for the effective development of such thin-poor reservoirs.However,with the deepening of adjustment and development and the deterioration of reservoir conditions,its inadaptability is gradually exposed during the application process.The main reason for this situation is that the current design standards and principles have not fully adapted to the reservoir conditions with further deterioration.Therefore,in order to improve the design coincidence rate and improvement effect of fracturing and completion engineering,the law of interference among fractures for thin interbedded reservoir is studied in this paper.Taking the axis of the casing as the centerline,an axisymmetric physical calculation model,including the casing,cement ring and surrounding rock in order from inside to outside,is established.Based on the physical model,a finite element model is established for solution analysis.Then the field test of subdivision control fracturing technology for Changyuan internal thin interbedded reservoir is conducted.With improving single-well productivity,reserve utilization and oil recovery as a goal,aiming at the main problems existing in current design and technology,systematic tests are carried out in different blocks of the Changyuan internal oilfield from multiple aspects,including fracture initiation law,interference law among fractures,scheme for holding,construction scale and displacement.A new set of design standards and specifications suitable for the present reservoir conditions is formed.It provides a technical guarantee for improving the overall development effect of thin interbedded reservoir.Based on the theory of interference among fractures and the field tests in thin interbedded reservoir,a set of subdivision control fracturing completion technology suitable for tertiary infill wells is developed.