High-pressure mixed gas generator used for petroleum thermal recovery gas injection machine

Abstract

The present invention relates to one kind of mixed gas generator for thermal petroleum extraction. The mixed gas generator consists of a head, a combustion section and a mixing section. It features the spiral cooling chamber structure inside the cooling water cap to cool the head effectively, the heat isolating cover and the cooling water jacket with multiple functions of heat insulating, preheating and cooling the combustion section, and the necked bush of the temperature regulator capable of ensuring the sufficient pressure field in the combustor to raise the combustion reaction speed. The mixed gas generator is for burning diesel oil with compressed air as the oxidant to produce high temperature and high pressure fume and spraying water to regulate temperature so as to generate mixed gas of N2, CO2 and water vapor injected into well for thermal petroleum extraction. The present invention is used in oil field to replace steam petroleum extraction.

Description

Technical field: [0001] The invention relates to a high-pressure mixed gas generating device used for a gas injection machine in petroleum thermal recovery. The device uses the high-temperature and high-pressure flue gas produced after the combustion of light diesel oil and compressed air to mix with water, thereby producing temperature and humidity that can be adjusted according to requirements. It is mainly composed of N 2 , CO 2 , water vapor (H 2 O) the composition of the gas mixture. The device is mainly used in the thermal exploitation of oil, and the mixed gas produced by the device is directly injected into the oil well, which can effectively improve the recovery rate of oil, especially heavy oil, and is an alternative to the traditional high-pressure steam boiler. New Technology. Background technique: [0002] The oil extraction process can be roughly divided into primary oil recovery, secondary oil recovery and multiple oil recovery. Steam oil recovery is a ty...

AI Technical Summary

Problems solved by technology

However, this device still has many deficiencies in structural design, which brings many difficulties to practical applications.

For example: 1. The combustion chamber is composed of an inner wall and an outer wall jacket. There is a spiral cooling water tank in the jacket. The cooling water tank is connected with an external cooling water closed-circuit circulation system to form a cooling system. This design adopts a direct cooling structure. , because the inner wall directly faces the combustion chamber, it is easy to be ablated by high-temperature flue gas. Due to the high water temperature in the cooling water tank, it is easy to scale, which makes the cooling water flow poor and even malfunctions. Due to direct cooling, the temperature of the combustion chamber is low (≤ 1300℃), resulting in difficult ignition, unstable combustion, incomplete combustion (black smoke from the outlet) and other consequences; 2. The closed-circuit circulation system for disposing of cooling water not only complicates the structure, increases equipment costs, but also wastes a lot of energy, that is, cooling The water circulation system takes away a lot of heat under normal working conditions, and this heat cannot be used, if it does not work properly, it will cause accidents, etc.

[0007] Compared with Chinese patent 03278103.2 "Petroleum Thermal Recovery Mixed Gas Injection Device" and Chinese Patent 200420054883.6 "Multi-functional High-Pressure High-Efficiency Burner", these two patented technologies are compared in terms of combustion efficiency, system thermal efficiency, manufacturing and operating costs, and operational reliability. The service life, the mobility of use and many other aspects have been greatly improved, but it has been proved by practice that there are also some deficiencies in its structural design and material use: 1. Under the condition of high oil well back pressure, the combustion chamber The high-temperature center of the medium flame gradually moves to the fire-facing surface of the head, which may easily cause the head to be burned (such as the fire-facing end surface, igniter ignition head, oil nozzle atomizer, etc.); 2. The refractory lining of the combustion chamber is exposed to high temperature and high pressure (2000°C, 16MPa) is prone to bursting and erosion, resulting in a significant decline in the use of the refractory lining, thus greatly shortening the service life of the burner (or gas injector) (sometimes less than one gas injection working day); 3 1. The material used at the exit of the combustion chamber, that is, the shrinkage cavity, is high-strength erosion-resistant corundum, but under the condition of extremely high-temperature, high-pressure airflow and high-speed erosion, this material is still prone to erosion, which affects the burner (or gas injection) 4. The diameter of the shrinkage cavity at the outlet of the combustion chamber is large, or the diameter of the shrinkage hole becomes larger after the erosion-resistant bushing at the shrinkage cavity is corroded, which will cause the combustion chamber to be difficult to ignite, or the combustion chamber will not burn after ignition. Complete (black smoke at the outlet of the generator) phenomenon, which affects the use effect of the device, resulting in a reduction in combustion efficiency and thermal efficiency

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