Puna Geothermal Venture has built a power plant in the Puna district of the Big Island. The plant is supposed to feed into the island’s electrical grid up to 25 megawatts of power generated by tapping geothermal steam from wells up to a mile deep. The plant has been completed for more than a year. For all intents and purposes, it has generated virtually no electricity.
At times, it has come tantalizingly close. In October of this year, for a few days, PGV was providing up to 10 megawatts of electricity to the grid of Hawaiian Electric Light Co., or HELCO. Success was fleeting, however, and when lightning struck the power line, a chain of events began that led once again to a shutdown of the plant and, eventually, of its only steam-producing well.
Some people are inclined to regard PGV as the unfortunate victim of a series of accidents that could have happened to anyone. Others regard the company as having invited disaster through its own ineptitude and bungling. Another view is that the very nature of the geothermal resource in Puna is such that tapping into it commercially is beyond the reach of existing technology.
A history of PGV’s operation over the last two years could support any one of these views, or a combination of them all.
A Helluva Well
Much of that history centers around the short life and slow death of what became known as well KS-8. (The KS is a prefix, standing for “Kapoho State,” used by the Department of Land and Natural Resources to identify wells in the particular area being developed by PGV.)
When drilling of KS-8 began in May of 1991, the stated purpose of the well was for reinjection of geothermal fluids. But three months earlier, PGV had been forced to abandon its production well KS-7 after a blow-out on February 21, and so the company was on the watch for a replacement. By late May, data gathered during the drilling led PGV’s managers to think they might be sitting on the geothermal equivalent of a gusher. On June 1, field manager William J. Teplow wrote to William Paty; chairman of the Board of Land and Natural Resources, summarizing the situation.
“Because of new geological data that has been gathered from the drilling of KS-3 and KS-7, PGV is now considering converting KS-8 from an injector to a producer,” Teplow stated. He added that staff from the state Department of Health (which regulates underground injection control – or UIC – wells) and the DLNR, which regulates production wells, had worked out with PGV the conditions under which conversion should be permitted (relating to pressure tests of casing, water sampling, and the like). Teplow was writing Paty to seek his review and approval of the conversion.
For the next few days, drilling continued without event. About a week into June, what were later described as “red flags” began to be observed by the drilling team.
At 6:49 p.m. on June 12, mud pumped up from the bottom of the well released a quantity of hydrogen sulfide gas, prompting several nearby residents to complain. After this small burp, however, conditions seemed to calm down for a while.
About 11 p.m. that night, just before a shift change, the drilling supervisor and another worker, called a tool pusher, left the area of KS-8 to go to their trailers. The driller remained alone on the floor of the rig, “drilling a well that had for almost a week been showing signs of becoming a problem well,” according to a later report.
At 11:16 p.m., all hell broke loose. The drill had punched through to a fracture in the Earth containing hot (633 degrees Fahrenheit) geothermal fluids under extremely high pressure (up to 1,950 pounds per square inch). The well “kicked” as the fluids shot up the bore hole to the Earth’s surface. Residents in the surrounding area were jarred awake by the unmuffled roar caused by the steam shooting out the well – a sound likened to what one hears standing at the end of a runway when a jet taking off. Concentrations of hydrogen sulfide (the acrid smell of rotten eggs, noticeable by humans when it is in concentrations as low as 3 parts per billion) rose into the parts-per-million range in some areas.
Well KS-8 continued its venting for the next 31 hours. For the next four months, the underground blow-out resisted control. It was not successfully plugged until September, when PGV announced that the well had been “killed.”
A Temporary Death
As a result of the blow-out, the County of Hawai’i and the state suspended PGV’s various permits. Independent consultants were retained by the state to report on the events that caused the blow-out and to recommend steps that should be taken to prevent further such occurrences. On February 28, 1992, when Mayor Lorraine Inouye, donning for the first time her hat as county Civil Defense director, approved the redrafted emergency response plan, the door was opened for PGV to resume drilling operations.
Operators lost no time in reopening the well whose death had been announced six months earlier. And the well, in turn, lost no time in reverting to form.
At 2:04 a.m. on March 22, well KS-8 “kicked,” with noise monitors reporting levels of 92 decibels at the plant boundaries. At nearby homes, noise levels reached 80 decibels. This time, the noise lasted barely a minute before valves could be shut, blocking the steam. (Because of that, Maurice Richard, then manager for PGV operations, was able to state that the average hourly noise level was just 38 decibels, well below PGV’s allowed 55 decibel hourly average.)
That didn’t stop PGV’s operations, but two weeks later, on April 5, Judge Shunichi Kimura did. Kimura, of the Third Circuit Court, granted a temporary restraining order banning drilling at PGV until such time as the state promulgated rules governing hydrogen sulfide emissions. Kimura based his order on a Hawai’i Supreme Court decision, which held that the state had erred in granting another geothermal company – True/Mid-Pacific Geothermal – a permit before developing uniform air quality rules.
By the time the rules were in place and other concerns had been addressed, it was well into August. PGV planned a 10-day flow test of well KS-8. About five days into the test flow, leaking valves allowed hydrogen sulfide to escape, raising levels in the surrounding area to as high as 80 parts per billion, more than three times the alert level specified in the new state rules.
Residents, meanwhile, were reporting yet another problem in the plant’s operation. Caustic soda, used by PGV to neutralize hydrogen sulfide, was raining down on some of the nearby subdivisions at distances of up to 2,000 feet from the plant boundary. Residents of Lanipuna Gardens experienced burning sensations on their eyes and skin as a result.
The leaking plumbing defied repair. After a second day of elevated levels of hydrogen sulfide, Steve Morris, successor to Maurice Richard as PGV manager, called a halt to the flow test – but not before declaring the test a success.
In late October of this year, PGV finally began producing electricity from the steam of well KS-8, increasing HELCO’s capacity by about 10 megawatts. Soon after start-up, the well head rose about nine inches out of its pre-production seating, but according to PGV, this was expected and well within the tolerances the plant was designed to accept.
On November 1, a Sunday, plant workers told Civil Defense Administrator Harry Kim that leaks in the system were causing hydrogen sulfide levels to rise to the parts-per-million range. Morris denied any problem.
That night, lightning struck the transmission line linking PGV to HELCO’s grid. The power plant had to be shut down, and with it, the pipes bringing steam to the turbines were closed. Steam pressure built in the well itself to the point where, apparently it caused the bond between the well head and lower pipes to rupture. The well head rose another four inches. According to one source who had talked with people working at the plant, before the decision was made to shut it down, the well rose a total of 28 inches. Also according to that same source, concerns over further expansion, or even of a blow-out of the well, were so great that plant operators placed I-beams and crossbars across the well opening, then parked two D-9 tractors on top of everything.
Steve Morris announced that while the expansion did not pose a safety problem, it was nonetheless “right on the edge of our comfort zone,” according to the Hawai’i Tribune Herald of November 3. In that same report, Morris was said to have attributed problems with the well to the June 1991 blowout, which stressed the well. The newspaper went on to quote Morris as saying the well also “may have been subjected to some degradation during prolonged idle periods resulting from legal and regulatory disputes.”
One more time, KS-8 was plugged. For a time, Morris seemed to hold open the option of resurrecting it as a production well yet again, but Land Board Chairman Bill Paty suggested not so subtly that the time may be at hand to let this one go. He put PGV on notice that the well could not be used for power production until the DLNR was assured it could be operated “in a safe and sustained manner.”
According to Hiram Young, the civil engineer at DLNR who has been most closely watching well KS-8, the expansion of the well head was caused by temperatures and pressures “higher than those experienced anywhere else” – 630 degrees Fahrenheit and 2,000 pounds per square inch, or, in other words, conditions almost identical to those that were present at the June 1991 blowout.
When asked if PGV might try once more to harness KS-8, Young was firm: “No,” he said. “We’ve put a gun to its head and shot it.”
After plugging KS-8 with cement, PGV focused its hopes on well KS-4. Although it had been planned as an injection well, PCV was wanting to turn it into a producer. But by late November, those hopes had been dashed. Although drilled to a depth of more than 6,000 feet, KS-4 would not be used for production, PGV manager Steve Morris announced.
Morris said that the company would have to start work on a new well, KS-9, complete it, and test it before it could produce power – a period that, under the best conditions, will take at least two more months. On the bright side, Morris said, by using KS-4 for injection along with KS-3 and KS-1A, the two injection wells already drilled, the company should have sufficient injection capacity to handle all 25 megawatts of power that the plant would eventually produce.
That did not impression Olson, a neighbor of the plant and one of its critics. “This is kind of like the captain of the Titanic reporting to the passengers that they now have an unlimited supply of ice,” he was quoted as telling the Hawaii Tribune Herald.
To Rise Again?
Whether KS-8 is truly dead may not be a matter for Young and other officials to determine. KS-8 has been plugged with cement down to 3,700 feet. But Wilson Goddard, one of the engineers retained by the state to review the June 1991 blow-out of KS-8, pointed out the problems with this approach. “You stop your ability to measure what’s going on in the well” when you plug it like that, he said in a recent telephone interview. “You don’t know if anything is moving behind the casing.” If deep, high-pressure fluids are pushed up and around the casing, the potential exists for large-scale contamination of potable water that runs through the Kilauea East Rift Zone, he said.
Hiram Young of the DLNR pooh-poohed Goddard’s concerns. He seemed satisfied with PGV’s claims that the well had been properly closed.
Goddard and others believe that the latest problems require the state once more to examine the operations of PGV. On November 12, he wrote Lewin of the Department of Health, proposing that the state do just that. As Environment Hawai’i went to press, the state had not responded.
Volume 3, Number 6 December 1992