The process of sludge treatment and oil recovery

Oily sludge in the oil field refers to the solid waste produced in the process of oil exploitation, transportation (conveying), crude oil storage tank and crude oil dewatering and settling tank bottom dredging, and oily sewage treatment. The composition of oily sludge varies with the production status of different oilfields. In general, the composition of oily sludge is complex, which is a highly emulsified system of oil-in-water and oil-in-water mixture. Oily sludge contains aging crude oil, wax, asphaltene, colloid, bacteria, salts, corrosion products, and a large number of oil displacement agents, demulsifiers, corrosion inhibitors, scale inhibitors, fungicides, and other water treatment agents added in the production process. Oily sludge is a hazardous waste (national Hazardous waste List HW08), if not treated in time, not only occupy a large number of arable land, but also the surrounding soil, water, and air will cause great pollution.

The process of sludge treatment and recovery

(a) Sludge fluidization and pretreatment. From the sludge in the pool or tank car charge of solid, flow pattern and flow of the sludge in excavator or pump directly sent to the sludge fluidized and pretreatment device for processing, sorting out large impurities after adequate cleaning and treatment with a screw conveyor to the sludge yards further depth processing, liquid into the oily sludge conditioning tank for quenched and tempered.

(b) Sludge conditioning and conditioning. One of the keys to realizing liquid/solid separation is to make the adsorbed oil with high viscosity desorption. In order to promote the separation of oil from the surface of solid particles, the sludge is conditioned and conditioned, and the sludge is further heated and homogenized to create better conditions for the desorption of oil from the surface of solid particles.

(c) Mechanical separation. After blending and tempering the oily sludge in centrifugal oil-water -solid three-phase separation processing unit, oil was further isolated recycling, transmission station to the system, purifying water enters back mixing tank as most isolated process water recycling, excess water is sent to the transfer station, solid isolated from the centrifuge to sludge yards after processing.

(d) Deeply treatment of oily sludge. The main treatment object of this step is the solid sludge separated from the previous stage (the content of petroleum substances is required to be less than 2%, otherwise the advanced treatment will be very difficult). After this step, the sludge can be disposed of at will and can meet the relevant indicators.