The $8 Million Question
In some ways, Deep Seas itself is a remote vehicle, directed by Chevron’s Houston office. This becomes clear on our return to Houston, where, the next morning, we watch Curt Newhouse at work. It’s just before 8:00, and Newhouse is sitting in a room with 20 other people, trying to make a decision. If his decision is wrong, it will be expensive; in his job, pretty much every type of error is. “No matter what, it always seems to take about $8 million to fix,” he says.
A Louisiana native, Newhouse has been working at Chevron for 24 years and is now senior drilling superintendent for Discoverer Deep Seas. Even though he’s running things, he’s only onboard about four to six times a year.
The room he’s sitting in is called the WellDecc, or Well Design and Execution Collaboration Center. Here, every morning, Newhouse and a group of geologists, petroleum engineers, and earth scientists – the subsurface team – gather to decide what to do next on Deep Seas.
In the WellDecc is a conference table that does not quite accommodate all the staffers. Crammed in, they all face a wide screen, which has a number of windows projected on it, controlled by a desktop computer and a wireless keyboard in front of Newhouse. One window is a video feed of the team on the Deep Seas, while another shows the group in the WellDecc. Another window is a graphic display of the progress of the bit, and the last is dense with numerical measurements from the well. Newhouse will move and manipulate these and add others throughout the conference.
Newhouse’s staff has been watching everything that has happened on the drillship in the past 24 hours. Information about mud weight, bit depth and speed, the resistance of the material being bored through (to determine whether it contains oil or water), and the kind of stuff coming up with the mud is all uploaded to Houston, where it is pored over in each cubicle until the group gathers each morning.
Because of what he has learned about yesterday’s drilling, geologist David Rodrick is worried that the bit is moving too quickly through the layers of the Miocene era, which settled between 5 million and 23 million years ago.
There are many such layers – containing a lot of sand – and Chevron numbers them by their rough age in millions of years. In this well, the bit is at M12, the pay zone is at M21, and each level is at a different pressure. Drilling from one layer down to another is a delicate operation, and the integrity of the hole is maintained by the pressure of the mud pumped into it. Too little pressure and the hole or the casing above it could collapse. Too much and leaks could develop, or fractures in the rock, disturbing mud circulation.
Having already drilled two wells nearby, the subsurface team knows that at M17, the pressure ramps up quickly. The $8 million question is when to stop drilling and step down to the next size in casing, which can withstand more intense pressure. Reduce the casing size too early and you needlessly lose valuable oil flow. “We don’t want a straw down there,” says Newhouse. “We want to see a good 30,000 barrels a day.” Stick with the bigger casing too long, and the deepest part of the well may collapse before it can be cased.
Newhouse, though, isn’t convinced the bit is close enough to the M17 sands to change the casing yet. He’s thinking about the future of the well, 10 years down the road, and he wants to see a good flow, not an overly conservative casing decision.
The group decides to continue drilling, but slowly, and to watch the numbers on their desktops as they come in. Rodrick is tentative about the decision. As the meeting is winding down, he reiterates, “You don’t want to get within 200 feet of those M17 sands, because those pressures will come up fast. If we don’t watch out, it’s going to eat our lunch.”