Fleeing sealing sand-prevention ignition method of fireflooding oil extraction

Abstract

The invention provides a fleeing sealing sand-prevention ignition method of fireflooding oil extraction which comprises preheating an oil layer, coking the oil layer, adjusting coking zone hole permeability degrees, oxygen-enriched ignition and the other steps. The fleeing sealing sand-prevention ignition method of the fireflooding oil extraction is suitable for ignition of heavy oil reservoir fireflooding oil extraction. Due to the steam preheating oil layer, ignition time of an oil layer is reduced; due to gas injection well (ignition well) immediate vicinity of wellbore coking, a role of fleeing sealing sand-prevention function can be played, and coking products (petroleum coke) is used as fuel; due to oxygen-enriched combustion, rapid ignition can be achieved; due to adjusting coking zone hole permeability degrees, hole permeability degrees and permeability of a coking zone of a gas injection well are increased; success rate of ignition is improved, and fleeing sealing sand-prevention ignition method of the fireflooding oil extraction is of great significance of improving economic benefits of the fireflooding oil extraction.

Description

technical field [0001] The invention relates to a fire flooding oil recovery technology for an oil well in an oil field, in particular to an ignition method for channel sealing and sand prevention in fire flooding oil recovery. Background technique [0002] Compared with other heavy oil thermal recovery methods, thermal flooding has many advantages such as wide application range, high oil displacement efficiency, and low cost, and can become an effective replacement technology for heavy oil recovery. Horizontal wells are applied to fire technology, which has the advantages of high recovery (>80%), high single well production, can solve interlayer contradictions, weaken intralayer contradictions, simplify plane contradictions, be easier to control, and have high comprehensive benefits. However, when using combined fire flooding of vertical wells and horizontal wells for ignition, a certain amount of air injection and injection speed must be achieved for successful ignition...

AI Technical Summary

Problems solved by technology

However, when using combined fire flooding of vertical wells and horizontal wells for ignition, a certain amount of air injection and injection speed must be achieved for successful ignition. This process can easily lead to problems such as gas channeling and sand production, especially for developed oil reservoirs. Moreover, when the horizontal and vertical distances between the perforation bottom of the gas injection well and the toe of the horizontal production well are relatively close, the gas channeling caused by the high-speed gas flow is greater, and the sand production is more serious, which may damage the horizontal section of the horizontal production well or even destroy the well. However, the current temperature-resistant plugging agent and anti-sand chemical agent cannot meet the requirements of high-speed airflow and high temperature in the ignition stage.

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