| At present,the oilfield development is mostly adopting the method of early water injection to keep formation pressure.With the depth of the oil field drilling,the moisture content of oil extraction is higher and higher.On dehydration of crude oil,the water tank,oil tank,sewage,etc.There is a large number of oily sludge at the bottom of the tank.At the same time,in oil field where finery sewage works(such as oil separation bottom,flotation cell,aeration tank,etc.)there is a large number of oily sludge.The composition of sludge is complex that belongs to the multiphase system,generally are the oil-in-water(O/W)、water-in-oil(W/O)and suspended solid,and emulsification,high viscosity,solid is.hard thorough settlement,bring great difficulty to sludge treatment.This paper is mainly talk about oily sludge after processing which through processes such as pretreatment,quenching and tempering,multistage centrifugal separation(sludge particle size in 2～3 mm or so commonly,oil is less than 2%,the water cut is less than 70%).Because the sludge particles through chemical demulsification,distillation separation,which has the different character from all the oil field production,contains a certain amount of oil cannot to separate out,it has influence on soil structure and permeability,damage plants,the aromatic hydrocarbons therein are also harmful to humans and animals,with polluting to the environment,cannot directly backfill.We can use the oily sludge has a certain size and block of pore throat in reservoir performance,sludge particle profile control agent,the oily sludge mixture stable suspension particles after processing reinjection formation,a sealing hole,coordination of injection-production relationship role.Use oily sludge particles after processing of reinjection profile,which can avoid environmental pollution,reduce the waste of resource and at the same time save the profile control cost,improve the oil displacement efficiency. |
