A downhole preheating and start-up method for super heavy oil reservoirs developed by dual horizontal well sagd

Abstract

The invention provides a method for downhole preheating and start-up of super heavy oil reservoirs developed by SAGD of double horizontal wells. The method includes: running concentric double oil pipes into well I and P well; injecting high-temperature fluid from the inner pipe of the concentric double oil pipe at the initial stage, and producing from the outer pipe of the concentric double oil pipe; Wells I and P are run into concentric pipes and resistance heating cables, and the surface temperature of the heating cables is set below the coking temperature of crude oil and continues to preheat; after tracking digital and analog monitoring, the fluid in the wellbore annulus is discharged when the interwell oil layer reaches the end of preheating conditions, and Inject solvent into the well; transfer to SAGD production stage. This method can realize the balanced preheating start of the SAGD horizontal section, promote the uniform development of the steam chamber in the horizontal section of the SAGD production stage, and effectively improve the oil production and recovery factor.

Description

A downhole warm-up start-up method for super-heavy oil reservoir developed by double horizontal well SAGD technical field The present invention relates to the exploitation method of the heavy oil reservoir in a kind of oil field, relate in particular to a kind of double horizontal well SAGD development The invention discloses a downhole preheating and starting method for an ultra-heavy oil reservoir, which belongs to the field of oil exploitation. Background technique Steam-assisted gravity drainage technology (abbreviation: SAGD) was invented by Canadian Bulter in 1978, Heavy oil reservoirs in sand mining areas, Liaohe Oilfield in my country, Xinjiang Oilfield and other places have been successfully applied. The principle is that the same oil layer is used. Deploy a pair of horizontal wells stacked on top of each other, and inject high-dryness steam into the upper steam injection well, because the density of steam is much smaller than that of crude oil The steam cav...

AI Technical Summary

Problems solved by technology

However, the price of the solvent is high, and after the solvent is produced on the ground, high temperature is required to separate it, which brings high costs, and the start-up of the solvent-assisted steam is also difficult to avoid the risk of preferential connection of the hyperosmotic section in the strongly heterogeneous horizontal section

Images