The Impact of Casing Damage Critical Condition on Marker Bed With Differential Internal and External Pressure in Daqing Oilfield

Abstract

During long-term development of Daqing oilfield of marker bed has been affected sliding between layers, causing a large area of casing damage. The marker bed casing damage mechanism has been basically clear at present, but the influencing factors of casing damage are not yet consummate. There is fluid impact of pressure on the casing on the marker bed, and fluid pressure on the critical conditions of casing damage has not yet been carried out in research. To research the critical conditions, taking into account the mechanics characteristics of the formation and elastic-plastic the finite element model has been established, and different sets of pressure differential as critical condition impact on casing damage were studied in this paper. The results showed that the internal and external casing liquid pressure difference has little effect on the formation of critical slippage. High internal casing pressure wells, with small casing damage critical slippage, are more likely to damage.