For drillers, The Geysers is a unique sort of hell.
It is one of the only places on Earth where a shallow well can reach a highly fractured reservoir so hot that it only produces steam.
That steam powers 18 power plants generating 835 MW of electricity, making this 45-square-mile area the world’s most prolific geothermal power producer.
High drilling costs there also stand out. Drilling a well requires 60 days or so and generates a lot of damaged drill bits and drillpipe.
The drilling rigs have the size and power of modern onshore rigs, but a close look reveals there’s no topdrive. Below the rig floor there is a rotary table, known as a Kelly drive because it can spin drilling pipe without being in the line of fire of the steam flowing out when running slotted casing into the steam-production zone.
When they get to that zone, they switch from drilling fluid and mud to injecting a high-pressure stream of air because of the enormous fluid losses anticipated when they reach that highly fractured level.
A drill bit that lasts 500 ft in this harsh, highly fractured rock has had a long run.
And the rugged terrain—mountains to a Texan but hills to a Californian—makes this a hard place to move a rig.
“The Geysers is its own animal, for sure,” said Sam Noynaert, a Texas A&M professor who was a key member of a team of drilling experts and scientists that drilled a well in The Geysers to test if faster drilling methods from the oil business could work there.
The two upper sections went pretty well, considering. As they went deeper, they repeatedly had to deal with severe fluid losses.
