Steam generation system and method for oilfield steam injection

Abstract

The present invention provides a steam generating system and method for oil field steam injection, wherein the steam generating system for oil field steam injection at least includes: a first steam generator, a steam-water separator and a second steam generator; the first steam generator includes The convection section, the radiation section and the superheating section, the first end of the convection section is connected with the first end of the radiation section, the second end of the convection section is connected with the water inlet of the first steam generator, and the first end of the superheating section is connected with the The exhaust port of the first steam generator is connected; the steam-water separator is provided with a steam inlet, a steam outlet and a demineralized water outlet, the steam inlet is connected with the second end of the radiation section, and the steam outlet is connected with the second end of the superheating section ; The water inlet of the second steam generator communicates with the demineralized water outlet. The invention not only realizes the recycling of heavy oily sewage, achieves the purpose of zero discharge, but also achieves the purpose of non-scaling of superheated steam.

Description

technical field [0001] The invention relates to the technical field of steam generation for steam injection in oil fields, in particular to a steam generation system and method for steam injection in oil fields. Background technique [0002] Heavy oil resources are widely distributed and abundant in reserves, with an annual output of about 15 million tons, accounting for more than 25% to 30% of the total oil resources. It has become one of the important energy guarantees for the rapid development of my country's national economy. my country's heavy oil recovery is dominated by steam injection thermal oil recovery, mainly including steam huff and puff, steam flooding and SAGD (Steam Assistant Gravity Drainage) and other technologies. Thermal recovery of heavy oil is accompanied by a large amount of heavy oil sewage with high temperature, high salt content and high organic matter content. After moderate treatment, the heavy oil sewage can be reused in steam injection boilers f...

AI Technical Summary

Problems solved by technology

[0005] For the first technical route, in order to avoid fouling of the drum furnace, the drum furnace has very high requirements on the water quality of the feed water. For example, GB12145 stipulates that the conductivity of the feed water of the drum furnace is less than 0.3μs / cm. In order to meet the water quality index of GB12145, heavy oil sewage A series of deep desalination treatments are required to reuse the drum boiler, such as using MVC (Mechanical Vapor Compressor). This technology is still in the field test and research stage in China. From the current test results, although it can reach GB12145 water quality requirements, but the cost of sewage treatment is relatively high, as high as 25-30 yuan / m 3 , the high processing cost limits the wide application of this technology in the field of SAGD oil recovery

[0006] For the second technical route, it is widely used in China, such as Chinese patent authorization announcement numbers CN201331047Y, CN206478614U, CN203286542U, CN201310875Y, CN201141592Y, CN104266175A, CN103968359A, CN103968365A, etc. These methods have their own advantages and disadvantages, and some of them are obtained by improving the desalination rate. To ensure that the superheated pipe is not fouled, some are to ensure that the steam drum is not fouled by increasing the blowdown rate, but these methods cannot meet the requirements of zero discharge of high-temperature and high-salt demineralized water. Adding salt-softened water into the superheated steam pipeline can meet zero emissions, but these methods lead to fouling and salt formation in the blender, steam injection pipeline and wellhead steam injection system, which seriously affects the safe production of heavy oil

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