Temperatures adequate for geothermal energy – PM

While permeability of the three wells drilled for geothermal exploration have not been favourable, temperatures are said to be adequate for the extraction of geothermal power.

This was the response of Prime Minister Dr Ralph Gonsalves to a question posed by parliamentary representative for West Kingstown, Daniel Cummings, in Parliament on January 22 regarding this country’s geothermal project.

In his preamble Cummings said: “it is a matter of public record that your highly optimistic statements on the success of the geothermal drilling program currently in progress at Bamboo Range, and the prospects for geothermal energy production in general are at odds with the reports that the Vincentian public has heard from the technical experts who are conducting the drilling”.

And the parliamentarian questioned about the depth for wells one and two; whether the permeability is suitable for the delivery of geothermal power, the cost of each well; and the power capacity expected from each well.

Rejecting Cummings’ statements on the project the Prime Minister said, his comments were not at odds with the reports from the technical people and clarified that three wells in total were drilled, not two.

“The conclusion in all of this, as provided by the technical persons, that although the results in relation to the permeability have not gone favourably due to the very tight fractures which have limited the permeability, the tested temperatures on the wells were adequate for geothermal power,” he said.

Gonsalves, who is the minister with responsibility for energy, addressed the status of each of the three wells.

The first well, SVG01 was drilled between April 30, 2019 and July 27, 2019 to a depth of 2700 metres.

The Prime Minister said that the first well faced several challenges due to unstable formations. The well later collapsed. He added that there were very few permeable fractures, but the temperature at 1880 meters was 155 degrees celcius.

“…The team is of the opinion, the technical team that there are still possible actions that can be taken to make a useful well. Hence the drill will return to the well and drill a side track path from 1880 meters to 2700 meters then stimulate for permeability,” Gonsalves said.

This first well cost US$7.17 million.

The energy minister said drilling on the second well, SVG03, began on August 7, 2019 and ended on October 29, 2019.

This well also recorded low permeability and collapsed at 1627 metres. Further stimulation is required and so the planned course of action is to continue stimulation of this well with increased pressure to open fractures and increase flow capacity.

Gonsalves noted that this well recorded temperatures up to 230 degrees celcius. And it cost US$7.16 million, inclusive of stimulation.

Work on the third well, SVG02, started on November 4 2019 and ended on January 5, 2020. Like the first two, it also recorded very little permeability. However it had the highest temperature measuring 230 degrees celcius; and it cost US$5.62 million.

The Prime Minister outlined several steps that will be taken in relation to the wells.

“…Given the disbursed budget to date and opportunity costs, the SVGCL, the management has discussed with the Caribbean Development Bank and the SVGCL board that all efforts should be made to all wells for geothermal production.”

He said the rig will be moved back to the first well to rectify the collapse by sidetracking and stimulation using what is called a down hole packer. This packer allows the casing to be sealed down hole at 1700 meters, thus allowing pressure to be applied beyond 1700 meters, resulting in an increased pressure on the formations”.

Given the success of stimulation with the first well, the rig will then be moved to the second well, SVG03, where the process will be repeated.

“Further stimulation on SVG02 will commence following SVG03 if deemed successful. Drill rig will be released after well stimulation and testing will commence after testing equipment is installed on site,” he added..

The energy minister said the well capacity for energy generation will be known hopefully, by July 2020, after well testing is done, and the economic analysis is updated.

As of December 2019, almost US$33 million has been spent on the geothermal project.

This amount includes US$3.974 million in grants spent on drill pads and water intake preparation, US$21.5 million via a contingent grant in drilling costs, US$792,000 from the Government of New Zealand, which was used for technical assistance drilling, project development costs from 2013 to 2019 amounting to US$5.98 million from equity partners, and US$650,000 from the government of SVG for project management from April 2019.

Additional funding is expected to come from the Abu Dhabi Development Fund, but only when drilling is complete.

“…when you are drilling for geothermal energy- the very manner in which this project was formulated was predicated on the clear idea that a geothermal drilling project is risky and capital intensive, and that is why as a first step in mitigating risks, that there was an extensive surface exploration undertaken by Reykjavik Geothermal…,” Gonsalves said.

He said it was for this reason that several tests were carried out beforehand to confirm the geothermal resource.