System and method for utilizing oil and gas wells for geothermal power generation

Abstract

A method and system for extracting geothermal heat from a well is provided, wherein the well casing has positioned therein an inner pipe nested within an outer pipe. The space between the well casing and the outer pipe may be filled with an insulating medium. A liquid heat conducting material flows into and down through the inner pipe. The inner pipe may be fitted with a one-way valve so that the liquid heat conducting material does not reverse direction and flow upwards towards the surface. As the liquid heat conducting material approaches the bottom of the inner pipe, it enters into a heat exchanger, absorbs heat and transforms to its gaseous state. The gas rises upward through the space between the outer pipe and the inner pipe and into the electricity generating component.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority based upon prior U.S. Provisional Patent Application Ser. No. 61 / 994,186 filed May 16, 2014 in the name of Richard L. Wynn, Jr., entitled “SYSTEM AND METHOD FOR UTILIZING OIL AND GAS WELLS FOR GEOTHERMAL POWER GENERATION,” the disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to the field of converting geothermal energy into electricity or other forms of work. More specifically, the present invention relates to capturing geothermal heat from deep within a drilled well and bringing this geothermal heat to the earth's surface to generate work, for example in the form of electricity, in an environmentally friendly process.[0003]Wells that have been drilled for oil and gas exploration that are either depleted, or have never produced oil or gas, usually remain abandoned and / or unused and may eventually be filled. Such wells were crea...

AI Technical Summary

Benefits of technology

[0014]The present invention discloses a system for generating electricity or other forms of work using geothermal heat from within a drilled well, comprising a heat harnessing component having a closed-loop heat extraction system. In various embodiments of the invention, the closed-loop heat extraction system consists of an inner pipe nested within an outer pipe, wherein the inner pipe and outer pipe are configured to create a heat exchange zone which cause a liquid heat conductive material within the inner tube to undergo a phase change to a gas phase. The rock or hot water surrounding the well casing heats the heat conductive material. Because the pressure change resulting from the liquid to gas phase change may cause back pressure on the liquid heat conducting material flowing into the inne...

Problems solved by technology

Wells that have been drilled for oil and gas exploration that are either depleted, or have never produced oil or gas, usually remain abandoned and/or unused and may eventually be filled.

Such wells were created at a large cost and create an environmental issue when no longer needed for their initial use.

While there are known geothermal heat/electrical methods and systems for using the geothermal heat/energy from deep within a well (in order to produce a heated fluid (liquid or gas) and generate electricity therefrom), these methods have significant environmental drawbacks and are usually inefficient in oil and gas wells due to the depth of such wells.

The water used for these systems is extremely harmful to the environment, as it is full of minerals, is caustic, and can pollute water aquifers.

In the case of EGS systems, water injected into a well permeates the earth as it travels over rock and other material under the earth's surface, becoming polluted, caustic, and dangerous.

A water-based system for generating heat from a well presents significant and specific issues.

For example, extremely large quantities of water are often injected into a well.

This water becomes polluted with minerals and other harmful substances, often is very caustic, and causes problems such as seismic instability and disturbance of natural hydrothermal manifestations.

Additionally, there is a high potential for pollution of surrounding aquifers.

This polluted water causes addi...

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