Application of dual pipe separate injection in heavy oil directional wells

The deep heavy oil reservoirs in Lukeqin oilfield have been produced by injecting fresh water at normal temperature.After applying separate injection,the success ratio of running-pulling tests is low,and washing and checking operations are frequent because of large casing size,high water injection pressure,high oil viscosity and hole deviation,thereby seriously limited the effect of water flooding development.The technology of dual pipe separate injection for directional well has been studied and applied in accordance with the characteristics of heavy oil reservoirs.This process avoids downhole running-pulling test.Accurate water injection at constant rate into sublayer,metering,distributing,separate layer pressure drop testing,selective acidizing or profile control can be realized on surface,thus extended washing and checking period,reduced cost,showing a promising application future.