Supercritical hydrothermal combustion type downhole steam generator for heavy oil thermal recovery

Abstract

A supercritical hydrothermal combustion type downhole steam generator for heavy oil thermal recovery mainly comprises a top end cover, a middle end cover, a reflux stable combustion area shell, a mainreaction area shell and a blending area shell which are connected and assembled sequentially; a cyclone fuel inlet and a heating rod are arranged on the top end cover; a heating rod inserting hole runs through the center of the middle end cover; the middle end cover is provided with a main combustion hole jet fuel inlet, a main combustion hole jet oxidizing agent inlet, a cooling water inlet anda swirl nozzle; the swirl nozzle communicates with the cyclone fuel inlet; the inner side of the reflux stable combustion area shell is wrapped with a composite spiral wall circumferentially; a main combustion nozzle structure is arranged at the bottom end of the reflux stable combustion area shell; the inner wall of the main reaction area shell is a spiral cooling wall; the main combustion hole jet oxidizing agent inlet, the main combustion hole jet fuel inlet and the cooling water inlet communicate with the main combustion nozzle structure and the spiral cooling wall correspondingly throughinner, middle and outer channels of the composite spiral wall; and steam can be efficiently generated in the stratum directly and heat loss in the steam conveying process is avoided.

Description

technical field [0001] The invention belongs to the technical field of heavy oil exploitation, and in particular relates to a supercritical hydrothermal combustion type downhole steam generator for thermal recovery of heavy oil. Background technique [0002] At present, oilfields mainly use steam injection boilers on the ground to generate steam, and then inject them into downholes combined with steam huff and puff, steam flooding and steam-assisted gravity drainage (SAGD) to recover heavy oil. The above methods mainly have the following bottlenecks: ( 1) Large heat loss. The smoke exhaust loss of the surface steam generator is about 20%, the heat loss of the surface gas pipeline is about 15%, the heat loss of the injection wellbore is about 10% per kilometer, and the overall thermal efficiency is low; (2) The reservoir depth is limited. In addition to the application depth of steam huff and puff up to 1800 meters, steam flooding and SAGD technology with high recovery rate ...

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Problems solved by technology

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a supercritical hydrothermal combustion type downhole steam generator for thermal recovery of heavy oil, aiming at solving the problem of steam injection in heavy oil thermal recovery of gas injection boilers The problem of high energy consumption and high pollution in the oil field, by combining the multi-component thermal fluid oil recovery technology with the supercritical hydrothermal combustion technology, can directly generate steam efficiently in the formation, avoiding the heat loss in the steam transportation process, and providing deep well , ultra-deep wells and offshore heavy oil production provide a practical means of oil recovery

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