Developing oil and gas fields often involves testing technology over years to ensure that it will function as expected when installed in a field. Lengthy tests are expensive and may delay start of production, but the cost of failures may far exceed the cost of testing. Failures in deep water are particularly expensive, but operations on land also may require extensive pilot tests to ensure that the technology is optimized for the resource.
A recent media tour of the Shell International E&P Inc. Gasmer prototype facility described tests on technologies for producing in two very different environments.
The facility currently has tests with in situ electric heaters for producing unconventional heavy oil and other tests with a subsea caisson electric submersible pump (ESP) for producing from ultradeep waters of the Gulf of Mexico and off Brazil.
Gasmer facility
Shell purchased the Gasmer site in 1960 and developed it initially to test riser tensioners for semisubmersibles. Over the years, various Shell companies have used the facility.
The facility is on a 30-acre site in southwest Houston. About 120 people are employed at the location.
The site is in a part of Houston that has seen better times. But redevelopment on three sides of the site is taking place in the form of a storm-water detention basin for Brays Bayou.
Shell notes that it has actively contributed to the Willow Waterhole Stormwater Detention Basin Project, which will add about 280 acres of green space to this part of Houston.
Electric heaters
During the tour, Shell kept the electric heater tests out of view but noted that the testing involved evaluation of different heaters for in situ upgrading of bitumen found on its leases near Peace River, Alta. Since 2004, Shell has had an ongoing pilot at Peace River with electric heaters placed in tightly spaced horizontal wells.
The heaters raise the temperature of the bitumen to lighten the produced fluid gravity to the mid-30° or lighter range from its initial 8-10° range. From the pilot, Shell has produced about 150,000 bbl of the upgraded fluid, leaving the heavier bitumen constituents in the ground.
Shell has plans to start another in situ upgrading pilot with electric heaters in its Grosmont carbonate leases, on the far-west side of the Athabasca oil sands region, which it acquired in 2006. The company expects to begin construction in 2009.
Also since 2000, Shell has conducted an in situ electric heater test for recovering liquids and gas from the Mahogany oil shales in Rio Blanco County, Colo.
Caisson ESP
The Gasmer facility has a full-scale installation for testing the subsea caisson ESP technology planned for the Perdido project in the Gulf of Mexico and the BC-10 project off Brazil (OGJ, May 5, 2008, pp. 53-64). Because of the water depths (7,500 ft at Perdido and 5,000-6,500 ft at BC-10) and the low reservoir pressures involved, both projects require pressure-boosting liquids at the seabed.
The boosting technology involves installing a ±330 ft, 42-in. diameter caisson in the seabed that contains an 8-10 in., 1,500-hp ESP. The multiphase produced fluid flows into the caisson’s top, where the associated gas separates out and flows up, while the liquid flows down and receives pressure boosting from the ESP.
Risers that allow direct vertical access connect the caissons to the Perdido regional host spar. At BC-10, the caissons connect to a floating, production, offloading (FPSO) vessel with flowlines and risers. Perdido will have five caissons for producing the three fields in the projects, while BC10 will have seven caissons for boosting production from the initial three fields. Expected production through each ESP is 25,000-30,000 b/d.
Shell began assessing the type of technology needed for the projects in 2003. During 2005, it did component testing and built the Gasmer test installation during 2006. In January 2007, it began the full-scale tests, and in 2008 it will start field implementation, although the company will continue running addition tests at Gasmer.
The full-scale test facility at Gasmer cost about $30 million, which includes about $14 million for the construction and $7 million for the testing.
