Device for in situ extraction of a substance comprising hydrocarbons

Abstract

A device for in situ extraction of a substance including hydrocarbons while reducing the viscosity thereof from an underground storage site is provided. The device includes at least one production pipeline leading out of the storage site, and at least two electrodes which are inductively and resistively effective relative to at least parts of the storage site.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2008 / 060074 filed Jul. 31, 2008, and claims the benefit thereof. The International Application claims the benefits of German Application No. 10 2007 036 832.3 DE filed Aug. 3, 2007. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention relates to a device for in situ extraction of a substance comprising hydrocarbons. The substance comprising hydrocarbons is conveyed from an underground storage site while reducing the viscosity thereof. The device comprises at least one production pipeline leading out of the storage site. Such devices for conveying substances comprising hydrocarbons are for example known from “Steam-Injection Strategy and Energetics of Steam-Assisted Gravity Drainage” by I. D. Gates, 2005, SPE International Thermal Operations and Heavy Oil Symposium, Calgary, Canada, Nov. 1-3, 2005...

AI Technical Summary

Benefits of technology

[0008]An object of the present invention is to specify a device for in situ extraction of a substance comprising hydrocarbons, in particular a device for conveying heavy oils or bitumen out of an oil sand storage site, which is an improvement over the prior art at least in that a reduced heating phase prior to the start of the production phase can be achieved.

[0024]The electric heater can be an alternating current heater. An alternating current heater prevents ions from migrating within the storage site. Advantageously carbonization or salt encrustation of the injection and / or production pipeline can be prevented in this way.

Problems solved by technology

The SAGD procedure currently practiced, as has been roughly outlined, exhibits various technical problems.

Firstly, hot steam can escape from the storage site via channels or porous rock strata present in the storage site, thereby reducing the thermal energy introduced into the storage site.

Excessive pressures in the storage site can result in soil distortions on the surface (blow-out), especially if the overburden is not very thick.

A further problem is “fingering” within the reservoir, whereby steam breakout (steam short-circuit) occurs generally at the start or end of the horizontal part of the parallel steam injection or production pipeline, when the steam seeks out a preferred communicating path between both pipelines and undesired pressure is dissipated, with the injected steam condensing and being conveyed through the production pipeline as water, so that less steam and thus thermal energy is supplied to the storage site and the effectiveness of the process is dramatically reduced.

Pressure and temperature within the storage site, for the rapid heating thereof, cannot therefore be increased arbitrarily, depending on the storage site conditions.

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