Double-tube jet flow uniform steam injection technology for horizontal well and assorted tool

Abstract

The invention provides a double-tube jet flow uniform steam injection technology for a horizontal well and an assorted tool. The assorted tool comprises a tubular column and a tubing nipple, and is characterized in that the tubular column is positioned at the lower end of a steam injection packer and is divided into a variable-density steam injection jet flow tube and a steam injection flushing tube; the variable-density steam injection jet flow tube and the steam injection flushing tube are connected with each other through a steam injection distributor; the variable-density steam injection jet flow tube is provided with a steam injection nozzle; a high-temperature rubber cup packer is arranged on the periphery of the variable-density steam injection jet flow tube; a high-temperature centering device is arranged between the variable-density steam injection jet flow tube and the steam injection flushing tube; and a screwed plug is arranged at the position of a port of the variable-density steam injection jet flow tube. The double-tube jet flow uniform steam injection technology replaces the original horizontal well steam injection technology, the assorted tool replaces the original tool, a range, which is 30-50 meters, of a group of steam injection points can be changed into a range, which is 15-50 centimeters, of the group of steam injection points, and the steam injection uniformity is increased by 50%, the steam using rate is increased by almost 30%, rising of edge and bottom water can be slowed down, and the recovery efficiency of an oil reservoir is improved.

Description

technical field [0001] The invention belongs to the field of petroleum exploitation technology, and relates to a technology and supporting tools for thermal recovery of heavy oil in horizontal wells and steam stimulation, and in particular to a double-pipe jet uniform steam injection technology for horizontal wells and supporting tools. Background technique [0002] There are mainly two types of horizontal well steam injection technologies currently used in various oil fields, one is double-pipe steam injection technology, and the other is multi-point steam injection technology for horizontal wells. The double-pipe steam injection technology requires the next two pipe strings to be composed of the outer vacuum heat insulation pipe and the inner layer without coupling oil pipe. The two pipe strings are respectively connected to the steam boiler. The advantage of this process is that the double pipes are injected from the top and bottom of the horizontal well respectively,...

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Problems solved by technology

The disadvantage of this process is that the steam injection point is only at the steam injection valve, and its heat transfer is through radiation or the flow of bottom hole liquid, which leads to uneven steam injection. When the horizontal well section is very long, there is no advantage of double-pipe steam injection from the bottom, resulting in less gas injection in the second half of the horizontal well

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