Thick oil mining method capable of strengthening waterflood efficiency by electric heating

Abstract

The invention discloses a thick oil mining method capable of strengthening waterflood efficiency by electric heating. The thick oil mining method comprises the following steps: fixing an electric heating tube or an electric heating cable outside an insulating tube with a groove in a ring-shaped mode, dropping the electric heating tube or the electric heating cable to a target oil deposit part through a production tube column, expanding the insulating plate for enabling the heating tube to cling to a production sleeve, and heating a stratum of an immediate vicinity of wellbore; after a heatingdistance reaches a preset value, continuously keeping heating, regulating heating power, and continuously reducing viscosity, flow resistance and a mobility ratio of thick oil of an area near a production well; starting a common thick oil waterflood mining process, injecting displacing fluid into an injecting well, and displacing crude oil in the stratum to move towards the production well; and lifting crude oil, water and gas, which flow to the production well, to ground by a lifting device in the production well. A hot mining way is combined with a cold mining way, so that flow resistance and displacement finger advance of the area near the production well are reduced, a waterflood production effect-taking period and thick oil mining efficiency are quickened, and a final recovery rate isincreased.

Description

technical field [0001] The invention relates to a heavy oil recovery method, which belongs to the technical field of oil recovery. Background technique [0002] Heavy oil contains a relatively high proportion of asphalt and colloidal components, and its underground viscosity is much higher than that of conventional crude oil (generally greater than 50mPa·s), resulting in poor fluidity of heavy oil and high difficulty in production. However, the viscosity of heavy oil is very sensitive to temperature. Usually, every 10°C increase in temperature can reduce the original viscosity by half. Therefore, thermal recovery methods are often used in the recovery of heavy oil, such as: steam flooding, steam huff and puff, burning oil layers, electric heating, etc., which are especially suitable for ultra- and extra-heavy oil with high viscosity (viscosity greater than 10000mPa·s). For ordinary heavy oil (viscosity less than 10000mPa·s), due to its own fluidity, it can be directly explo...

AI Technical Summary

Problems solved by technology

[0003] However, there are still some problems in the actual production of water flooding heavy oil technology: First, the production effect is slow and the initial production is low

However, the above-mentioned patented technologies only involve a single thermal or cold recovery method of heavy oil, and cannot simultaneously solve the problems of slow effect, severe fingering and low sweep coefficient in the process of ordinary heavy oil cold recovery.

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