A heavy oil recovery method using electric heating to enhance water flooding efficiency

Abstract

A heavy oil recovery method that enhances water flooding efficiency by electric heating. First, the electric heating tube or electric heating cable is fixed in a ring shape outside the isolation tube with grooves, and the production string is lowered to the target oil reservoir, and the isolation tube is expanded and isolated. The heating tube makes the heating tube close to the production casing to heat the formation near the well; after the heating distance reaches the preset value, the heating is continued and the heating power is adjusted to continuously reduce the viscosity of the heavy oil near the production well. Flow resistance and mobility ratio; start the ordinary heavy oil water flooding production process, inject displacement fluid into the injection well, and displace the crude oil in the formation to move towards the production well; the crude oil, water and gas flowing to the production well pass through the lift in the production well The device is lifted to the ground. The invention combines thermal recovery and cold recovery, reduces the flow resistance and displacement fingering in the near-well area of ​​the production well, accelerates the effective production period of water flooding and the recovery efficiency of heavy oil, and improves the ultimate recovery rate.

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.

Images