Damage Evaluation Of Cementing And Completion In Low Permeability Reservoir In Block A

This paper mainly introduces the reservoir protection technology of A block in low permeability oilfield.A block velocity sensitivity of the damage to a lesser extent,belongs to the medium to strong water sensitivity,the water sensitive coefficient in 0.20 ~ 0.50,the critical salinity of 2500mg/L,as the medium weak salt sensitivity,acid sensitivity is medium,the sensitivity index is about 0.30 ~ 0.60,alkali sensitivity is weak the base,no damage.In this paper,reservoir protection drilling fluid and completion fluid,cement slurry and perforating technology difficult to start,mainly for drilling and completion fluids on reservoir damage,cement slurry in the process of reservoir damage and perforation technology to lift the drilling and completion of pollution.The preferred zwitterionic polymer drilling fluid is suitable for drilling in low permeability reservoir in A block,and has better inhibition and less than 2% expansion rate.The solid phase of drilling fluid can not penetrate into the pore of core.Under the action of pressure difference,the invasion depth of filtrate is less than 10 cm,and the damage rate of permeability is less than 10%.The main way to control cement slurry formation damage is due to the loss of control of cement slurry,mud cake and the effect of adding high filtration reducing agent,water loss of the cement slurry from 1000 m L to 28 m L,the filtrate invasion depth is less than 5cm,the permeability damage rate is less than 10%.The optimized perforating fluid has small damage and high recovery rate,and can relieve drilling fluid plugging.Through experimental analysis,the damage characteristics of reservoir damage characteristics of drilling fluid and completion fluid to the reservoir and cementing process,established the completion process of reservoir protection strategy,in the process of cementing and perforation in the process of reservoir protection strategy of reservoir protection strategy to reservoir protection effect is good,the field test was also success,to meet the requirements of the block reservoir protection.