Electric heating type downhole steam generator

Abstract

The invention relates to the technical field of heavy oil thermal recovery in petroleum engineering, in particular to an electric heating type downhole steam generator. The generator comprises an inlet part, an electric heating part and an outlet part which are sequentially connected from top to bottom, wherein the electric heating part comprises at least one heating section; each heating section comprises a heating section casing and multiple heating tubes arranged inside the heating section casing; electric heating wires are arranged in all the heating tubes, and positions between the electric heating wires and the heating tubes are filled with insulating and temperature-resistant materials; space allowing water to flow through is formed among the heating tubes and between the heating tubes and the heating section casings; a water inlet is arranged at the inlet part; and a discharge port is arranged at the outlet part. High-temperature steam is produced downhole and directly injected into an oil layer, the heat loss is reduced, the energy utilization rate is greatly increased, and the generator has the outstanding advantages in deep well and extra-deep wells; and the electric heating wires are arranged in the heating tubes, so that the generator is convenient to mount, good in reliability and more beneficial to steam generation.

Description

technical field [0001] The invention relates to the technical field of heavy oil thermal recovery in petroleum engineering, in particular to an electrothermal downhole steam generator. Background technique [0002] my country has abundant heavy oil resources, but the cost and difficulty of exploitation are relatively high. In thermal recovery of heavy oil, steam flooding is one of the most widely used and mature methods. [0003] Steam generator is one of the indispensable equipments of steam flooding technology. At present, the most common method is to generate high-temperature and high-pressure steam on the ground, and inject it into the downhole heavy oil reservoir through insulated pipelines. The equipment on the well of this technology is bulky and requires a high investment in supporting facilities. The exhaust gas takes away a lot of heat energy and pollutes the surrounding air; and after the surface steam passes through a long pipeline, the energy loss is large, and...

AI Technical Summary

Problems solved by technology

[0006] (1) It is inconvenient to install, and it is easy to cause bumps and damage the heating wire;

[0007] (2) Due to the limitation of the size of the underground, the distance between adjacent heating pipes is very small, and the heating wire is wound on the outer surface of the heating pipe, which may cause contact and generate electricity, thereby causing failure or damage to the heating pipe;

[0008] (3) The heating wire is wound on the outer surface of the heating tube. Since the supporting partition will be in direct contact with the heating wire, it is necessary to insulate the contact position, which increases the cost;

[0009] (4) Under the premise of ensuring the heating temperature, the inner diameter of the heating tube is limited, so that the amount of steam generated is limited; if the number of heating tubes is increased, the diameter of the shell will inevitably be increased, which increases the difficulty and cost of the use of the equipment

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