Method for exploiting thick-layer oil deposit in combustion of oil in situ

Abstract

The invention provides a method for exploiting a thick-layer oil deposit in the combustion of oil in situ. The method includes the following steps that at least one vertical well or inclined straight well is arranged in a natural perpendicular crack area or a non-natural-perpendicular-crack area, and run casing completion is conducted; a high-temperature resistance packer is arranged and located above the bottom boundary of a target oil layer by 2-3 meters; when the non-natural-perpendicular-crack area is selected for arranging the well, a perpendicular crack penetrating through the whole target oil layer is arranged and generated in the target oil layer in the non-natural-perpendicular-crack area; a propping agent is injected in the perpendicular crack; an electric ignition or chemical ignition manner is used for igniting a fuel layer; oxygen-containing gas or matter generating oxygen through pyrolysis is injected into the target oil layer; an electric submersible pump is used for production or a coiled tube is used for gas injection for production, and when the front edge of a fire wire moves downwards to the packer, production is over. According to the method for exploiting the thick-layer oil deposit in the combustion of oil in situ, a large amount of operation cost can be saved, and economical and efficient combustion of oil in situ development of the thick-layer oil deposit is achieved.

Description

Technical field [0001] The present invention relates to a method for burning oil reservoirs, in particular to a method for exploiting thick oil reservoirs by burning oil layers for thick massive oil reservoirs with fire flooding assisted gravity drainage to improve crude oil recovery, and belongs to the technical field of oil exploitation . Background technique [0002] The fire drive technology can be divided into forward combustion and reverse combustion according to the direction of the injected air and the movement direction of the combustion front; among them, the injected air of the forward combustion and the movement direction of the combustion front are the same, which is called forward combustion; The direction of combustion air flow is exactly opposite to the direction of movement of the combustion front, which is called reverse combustion or reverse combustion. Forward combustion is divided into dry forward combustion and wet forward combustion according to whether wa...

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Problems solved by technology

[0004] 1. In the process of fire flooding development, injection wells and production wells are deployed in a certain well pattern, and adjacent injection wells and production wells are separated by a certain distance. However, due to the influence of reservoir heterogeneity, the distance between injection wells and production wells Usually, there are a large number of high-permeability strips, and these high-permeability strips will become the main area to attract the fire line during the injection of air fire flooding, which brings great difficulty to the ground operation

And often due to insufficient understanding of underground heterogeneity, operational errors and premature breakthrough of production wells are caused, which bring serious hidden dangers to safe production

In addition, due to the local breakthrough of the fire line, a large number of areas have become the flow around the fire line, and normal combustion cannot be carried out, resulting in a large loss of reserves and low recovery

[0005] 2. Especially for thick oil reservoirs, due to the overlapping effect of the fire flooding line, the injected air tends to migrate to the top of the oil layer due to its low density, so the top of the oil layer is often burned preferentially, while the middle and lower parts of the oil layer are often difficult to burn effectively. And conventional combustion methods are difficult to effectively control the combustion of the middle and lower oil layers

[0006] At present, there is no public effective method to achieve effective control of conventional fire formation in thick heavy oil reservoirs

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