A New Power Source from the Earth: Turning geopressure into electricity

We ran a story earlier out of Texas about Free Green Energy, LLC, where they announced the engagement of San Antonio based Sologen Systems, Inc. as the project manager for a geopressure electrical generating project, and we simply had to find out more. The company is built on the concept of harnessing the kinetic energy of pressurized oil, gas and geothermal resources and converting this energy – the kinetic energy – directly into electricity.

We have previously reported on a DOE initiative that would demonstrate low temperature geothermal electrical power generation systems using oilfield fluids produced specifically at the Rocky Mountain Oilfield Testing Center in Wyoming. This company could take oil, gas and even geothermal production into a whole new realm.

Free Green Energy was organized in 2008 to identify and develop geothermal and geopressure energy resources and use them to generate and sell green electricity. It has a joint venture with Green Well Renewable Power, and its 80% owned subsidiary, Green Well Power LLC, to tap the kinetic and/or geothermal energy from 100 wells in Texas and Louisiana.

Green Well Renewable Power is funding the commercialization of what is called the Linear Drive Engine to harness the kinetic energy potential of these wells. Green Well Power is the exclusive North American licensee for the technology, developed and patented by Linear Power, Ltd of Long Beach, Mississippi.

The Linear Driver Engine is a piston engine with no crankshaft. The company claims the technology can be implemented easily and inexpensively and can withstand changes in flow-rate and pressure, as well as the highly corrosive conditions that are a part of every day oil and gas production.

The continuous flow of any high-pressure gas and/or liquids through the engine delivers continuous force in order to produce direct generation of AC or DC power. This is accomplished through the connection of the power output rod to a linear-to-rotary-motion conversion transmission, via a 90 degree perfect vector angle. Green Well Renewable Power says this provides maximum power transfer to drive a standard rotary electrical alternator. Used with a closed-loop power plant, the system has near zero environmental impact.

A geopressured resource is commonly hot salty water saturated with natural gas that can be found in large, deep aquifers that are under higher pressure due to water trapped in the burial process. These resources are often found at depths of 9000 ft to 18,000 ft. with water temperature ranging from 190 F to 390 F.

An oil field co-produced resource makes use of wells already drilled by the oil and gas industry that are either deep enough to encounter hot water, or could be deepened into these hot zones. The company notes that a depth of 15,000 ft or more is preferred where pressures will be optimal. It also quotes scientists at Southern Methodist University as saying that producing energy from oil and gas fields in Texas alone could result in between 400 and 2200 MW of geothermal power.

The project now being implemented calls for developing a total of 200 geopressured wells – double the number from the original joint venture announcement – in Mississippi and Texas. The project is expected to ultimately generate baseload electrical power of at least 400 MW at a capital cost estimated at $280 million.