Bitumen Production via Steam
Jane Van Ryan
Posted August 11, 2009
Day Two of the oil sands tour, August 7 - About 60 kilometers southeast of Ft. McMurray, Alberta, ConocoPhillips is producing crude oil from oil sands using a process called in-situ development. In concept, in-situ development sounds fairly simple. The oil sands are heated underground with steam, gravity pulls the hot oil down toward a wellbore, and the oil is brought to the surface.
Simple, right? Not really. In actuality, the process requires high-tech engineering, precise execution and the ability to see underground using sophisticated seismic testing and monitoring equipment.
At ConocoPhillips' Surmont location, the oil sands are too deep for mining operations. Situated in a forest, the Surmont facility is producing 19,000 barrels of oil per day and is ramping up to produce 27,000 barrels per day.
The oil is produced by drilling pairs of wells about 400 feet apart. Each pair goes down vertically for about 1,000 feet and stretches out horizontally for another 3,200 feet near the bottom of the oil sands formation. The wells must be drilled about 15 feet apart with one on top of the other. The upper well carries steam to heat the oil sands formation; the lower one, which must be at or near the bottom of the oil sands pay zone, brings the heated oil to surface. This process is called Steam Assisted-Gravity Drainage (SAGD).
Unlike the soft, pliable oil sands at the Syncrude location, this oil clogs the pores of sandstone and is thicker than peanut butter. It's called bitumen, and some Canadians laugh that it's nearly as solid as a hockey puck. Still, ConocoPhillips reports that operators get about six times as much energy out of the formation as they put into it, making bitumen production a worthwhile endeavor.
To produce the oil, the field operators can inject natural gas into the wells to make it bubble up, or they can pump it. Once the oil is out of the ground, the water is removed and a diluent is added for blending (ConocoPhillips uses synthetic oil). The water is treated to take out any residual oil and hardness and then it is sent to the steam generators and back into the ground to produce more oil.
This closed loop system has proven to be very efficient. About two-and-a-half barrels of water are needed to produce one barrel of bitumen, and 90 percent of the water is recycled. The remaining water, accounting for about a quarter of a barrel of water, is pumped from the Grand Rapids Sand formation below ground, which contains brackish, non-potable water. No fresh water is needed.
In-situ operations require a smaller footprint than mining. And ConocoPhillips' Surmont facilities are built to be removed easily, leaving no lasting impact on the land. The buildings and well pads are on a thick coating of gravel, which can be removed and used elsewhere, and the land can be replanted with native vegetation. Even the housing for the workers is portable. Those who choose to stay at Surmont rather than drive a long distance home every day can live in one of the small sleeping rooms near the dining hall, community center and the work-out room--all of which are in trailers.
Many of the workers enjoy the opportunity to lift weights and run on the treadmill. Surmont's operations manager discourages them from jogging along the dirt roads that connect the two well pads to the processing facility. Too many black bears, he says. During the tour, we saw a red fox and a coyote, but fortunately no hungry bears.
Wildlife is abundant in the forests and meadows of Alberta, and oil companies are doing their part to help the Wood Bison herd. More on that tomorrow.
About The Author
- Blogger Conference Call - Oil Sands Development and the Keystone XL
- Blogger Conference Call - ExxonMobil Earnings and Taxes
- Blogger Conference Call - Industry Earnings and Public Pension Plan Ownership
- ETR 130 - The Oil and Natural Gas Industry's Contribution to State Pension Plans
- Keystone Pipeline: The Sooner, the Better
- Capping Stack: A Positive Outcome from a Tragic Accident