Through every decision and action we take at Ventia, we have an opportunity to make a positive impact on the people and the world around us. A core part of our purpose is continually looking for innovative ways to deliver projects that minimise our environmental impact. 

In 2009, Ventia's Rig & Well Services team (previously known as Easternwell) was engaged by Geodynamics (now ReNu Energy) to drill wells - four to five kilometres deep - for its new enhanced geothermal energy project in South Australia's Cooper Basin. 

Geothermal energy is heat from the Earth. It is a renewable energy source with multiple applications including heating, drying and electricity generation.

Renewable energy innovation

Heat is contained in the rocks and fluids beneath the Earth's crust, and can be found as far down as the Earth's hot molten rock. Geothermal systems extract the Earth's heat in the form of hot water or steam. The temperatures encountered determine the possible uses of its energy.

In the case of the Cooper Basin, hot granite rocks reach temperatures more than 280 degrees Celsius. 

The wells Ventia delivered for this project successfully encountered hot water below the Earth's surface, of sufficient temperature to drive a steam turbine and produce electricity - becoming the first demonstration of Enhanced Geothermal Systems (EGS) electricity generation in Australia. 

However, in recent years the geothermal industry pace has slowed, as the cost to deliver geothermal energy in Australia has limited its competitiveness in the market when compared to other renewable energy alternatives such as solar and wind.

The Australian Government Renewable Energy Agency (ARENA) says Australia has considerable geothermal energy potential, however the electricity produced is not financially viable in this country due to the challenges in identifying suitable geothermal resources; producing hot fluid from the geothermal reservoirs at a high rate; and overcoming the significant up-front capital costs associated with enhanced geothermal system technologies and the cost of transmitting electricity from remote locations.

The project therefore closed in December 2015. 

Sustainability in action

As part of our commitment to sustainability, Ventia remediated the wells drilled more than a decade ago.

Our involvement in this landmark project - from development through to remediation - is a great example of our vision in action: harnessing the power of technology and being sustainable in all that we do. 

At the time it was delivered, this project was revolutionary and required specialist technology and skills to deliver Australia's most technically challenging wells.

Ventia facilitated the purchase and operation of a fit-for-purpose rig to carry out construction of the wells. At the time there was no other rig in Australia with the necessary capability.

The rig was more than 50 metres high and required more than 20 specialist tradespeople and crew members to operate it at any one-time.

Ventia operated the rig for more than two years providing the operations, engineering and maintenance services and ultimately successfully delivering two deep wells.

Ventia's Rig and Well Services General Manager, Kyle Koziol, said: "Ten years ago the project with Geodynamics (now ReNu Energy) was our first big step into exploring the viability of renewable energy sources."

It was a technically challenging project that provided us with lots of opportunities to grow and learn, leading us to support other emissions reduction technology projects such as carbon capture and storage. 

"Ventia is proud of the part we played in this important and innovative exploration of new renewable energy sources, and we watch with interest the further development of this industry and technology in the future."

Project achievements

• Each well was drilled to depths of between four and five kilometres. Examples of drilling parameters and challenges managed by the drilling team included:
• Under balanced and managed pressure drilling (through production zone).
• 9-5/8" casing runs to 3,500m + (pressure tested to 6,000psi).
• Drilling through deep granite - 1,200m +.
• High mud weights - 17ppg (differential sticking).
• Total and partial losses of circulation.
• Bottom hole temperatures of >260°C.
• Borehole stability through coal sections.
• Dual BOP stack; 13-5/8" 10K and 20-3/4" 3K.
• Sub-contractor management (15+ contractors on-site).