Water treatment process for recovering heavy oil recovery produced water to serve as boiler feed water

Abstract

Disclosed is a water treatment process for recycling produced water from heavy oil recovery to serve as boiler feed water. Inlet water containing produced water as the main component is conveyed to a vertical falling-film evaporator equipped with a brine distribution device, so as to produce distilled water as boiler feed water through evaporation. Scrubbing particles are added to the inlet water containing the produced water as the main component or to circulating strong brine of the vertical falling-film evaporator to form slurry. When the slurry is evaporated by the vertical falling-film evaporator, scaling on the heat exchange surface of the evaporator is prevented or reduced by utilizing the solid particles in the slurry. According to the process, most of produced water is processed into high-quality distilled water used for a boiler to produce steam so as to increase the heavy oil recovery rate, and the process can be directly used for treating the produced water, with a recycling rate higher than 95%, to produce the high-quality boiler feed water used for producing the steam required by heavy oil recovery. The process can also be used for treating boiler blow-off, thereby reducing the emission of a factory, lowering the requirements of physicochemical treatment, and increasing the overall water recycling rate of a water treatment plant.

Description

technical field [0001] The invention belongs to the field of water treatment and relates to a water treatment process for recovering heavy oil production water as boiler feed water. Background technique [0002] Heavy oil recovery involves injecting steam into oil-bearing formations and recovering oil-water mixtures from oil wells. The oil is separated from the water, and the separated water is produced water. In order to recycle the produced water to produce steam, the produced water must be treated to meet the requirements of the steam generator or boiler for steam production. [0003] Steam injection into heavy oil reservoirs is a widely used method for enhanced oil recovery. Typically several tons of steam are required to produce 1 ton of heavy oil, and the steam / oil ratio is often referred to as the oil recovery ratio (SOR). Because the SOR value is generally between 2 and 4, and the water consumption is high, environmental protection and economical aspects encourage...

AI Technical Summary

Problems solved by technology

Regardless of the process used, the difficulty to be overcome in the produced water evaporation process is that silicon components and hard components are easy to scale, which affects the operation of the evaporation system

In addition, due to the presence of volatile components, such as organic matter and carbonate, more production costs are required for evaporation to produce distilled water, because additional water treatment facilities need to be set up, the chemical composition of boiler feed water is higher, and the boiler blowdown is higher

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