Caroline

Timeline

• 1986
  • Shell discovers the Caroline gas field – the biggest in twenty years
• 1988 – 1989
  • Shell conducts public consultations on how to develop the field
• 1989
  • Shell applies for regulatory permission to build Caroline Complex
  • Huskey submits a competing proposal
• 1964
  • Wild Horse Creek gas field is discovered
• 1990
  • After a public hearing, Shell wins the approval on August 31 and starts construction
• 1991
  • Recruiting of employees begins and more than seven hundred applications are received
• 1992
  • Caroline gets Alberta Environmental Protection approval
  • Sundre Petroleum Operators Group (SPOG) begins operating and puts in place an emergency 1-800 number
• 1993
  • Train I start-up on March 3
  • Well 6 becomes the first well started in the Caroline field
  • Train II start-up on May 5
  • Caroline start-up experiences technical difficulties
• 1994
  • Pipeline leak, clean-up and remediation
• 1995
  • Public open house regarding lowering stack temperature and the upcoming major plant Turnaround
  • Major plant Turnaround corrects technical difficulties
  • Performance tests show extra plant capacity
  • Shell applies to lower stack temperature
  • Cobra Maintenance replaces Quinn Contracting as Shell'’s Alliance Maintenance contractor
• 1996
  • Shell obtains approval to lower stack temperature
  • Shell applies to process more gas, and participates in a hearing
  • Met commitment for Caroline Livestock Study, then study is taken over by SPOG
  • A Public open house is held regarding proposed license increase
• 1997
  • Caroline obtains approval to process 15% more gas
  • Shell participates in an Interrogatory Process
  • Second Plant Turnaround improves performance and begins operating at 123% design
  • Sulphur Storage tank is bypassed
  • SPOG holds communication workshop which results is thirteen community members, representing geographical areas, joining SPOG
• 1996 - 1999
  • Workover wells in Caroline field and bigger tubing is installed to increase production
• 1998
  • Caroline celebrates its 5th Anniversary with a public openhouse and tour
• 2001
  • Drill replacement well at 7-30-35-5-W5M to replace Well 3 that had watered out
• 2002
  • Shut down of Liquid Acceleration Project and workover of Well 13 to change from injection to producing well
• 2003
  • Two-stage Central Compressor Station to increase production
  • Gas leak from aerial cooler at South Compressor Station
  • Shell Caroline begins to take in third party gas from Hunt Oil’s newly constructed inlet facility
  • Caroline celebrates its 10th Anniversary
• 2004
  • Two-stage at South Compressor Station to increase production
• 2008
  • 15th Anniversary is celebrated

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Discovery

While many people were involved in successfully finding and later developing the Caroline gas field, it was the efforts of one individual who had one of the largest roles in finding the southern extension of the Beaverhill Lake formation which eluded explorers for so many years.

In 1981, Pat Lee, a young geologist only three years out of McGill, came up with the idea which ultimately led to the discovery of the largest gas field in Western Canada in the last twenty years. Lee came up with a theoretical model that apparently could show the correspondence between seismic results and the porosity of rocks in the Beaverhill Lake Formation. When she applied her model to seismic readings from the Caroline area, the model suggested a porous bank edge at a depth of 3 800 metres. Skeptics in the company questioned Lee’s assumptions and her work was shelved for a few years. In the interim, two other competitors drilled dry holes on the west and east edges of the Caroline gas pool. But it wasn’t until the mid-eighties that Shell acted on Lee’s assertions. Shell drilled the Caroline discovery well in 1986.

The Shell Caroline field was discovered in February 1986. The discovery well was located at 7-18-34-4-W5M, 6.4 kms (4 miles) SE of the James River Store and south of Highway 587. It was drilled by Hi Tower 18E. It is currently called Caroline Well 23 and is located near Shell’s South Compressor Station.

Subsequently fourteen other wells were drilled. Gulf Canada drilled 8-1-36-6 and Canterra (Husky) drilled 6-2-35-5. The balance of the successful wells were drilled by Shell Canada. The wells produced from the Swan Hills member of the Beaverhill Lake formation, which is generally found to be3 600 to 3 850 metres (12 000 – 12 600 feet) below surface and contains approximately 35% H2S or sour gas.

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All About Caroline

Field Facilities

Wells

• The fifteen wells in the Caroline Field produce:
  • 400 000 to 2 million cubic meters per day of raw gas
  • 200 000 to 1 million cubic meters per day Condensate
  • 0 to 5 cubic meters per day of water (1 cubic meter = 6 barrels)
• H2S 35%
• Well Depth between 3.5 to 4.5 km deep, which is 35 000 to 45 000 meters deep or 2 to 2.5 miles

Gathering Pipelines

• Pipelines Cost – approximately $120 million
• Pipe Sizes – range from 3” to 16”
• Pipeline Length – 217 km (135 miles) or pipelines and 66 km (41 miles) of right-of-ways
• Burial Depth – 1.1 m (3.6 feet) of cover minimum
• Operating Temperature– 75° C gathering system
• Before use, all welds are x-rayed, sour lines are tested to 1.5 times the operating pressure, and inspection is provided to check the interiors

Compressor Stations

• Facility Costs – approximately $130 million
• Three Compressor Stations
• Electric driven centrifugal compressors (to reduce the noise level)

Discovery and Development

Discovery

• The discovery well was drilled by Shell in January 1986 in the James River Area
• 15 producing wells drilled in total
• 8-1 drilled by Gulf, 6-2 drilled by Husky

Development

• Shell held thirty major public meetings to exchange information on the project in the communities
• Established three community offices
• Attended more than 2 500 meetings with interesetd individuals
• CAB – Caroline Advisory Board was created in January 1988, consisting of five municipalities in the area
• BLCOA – Burntstick Lake Cottage Owners Association was created in 1989 to deal with concerns of the residents of Burntstick Lake with the project
• PALSS – Prevention of Agriculture and Living Space Society was created in January 1989 to deal with concerns of proposed rail line
• CRAG – Concerned Residents Action Group was created in September 1989 to deal with concerns of residents in the area of the proposed plant site
• A hearing was held in the Village of Caroline. It lasted from April to May 1990 with over forty intervenors
• A convoy of over 400 vehicles paraded through the streets of Sundre in support of the project
• August 31, 1990 – The Energy Resources Conservation Board gave Shell the approval to build the Caroline Complex

Construction

• Started October 15, 1990
• 700 job applications received per month
• Local Opportunities program is put in place
• Total cost of Gas Plant, Field Facilities, Shantz Sulphur Forming – $1 billion
• Thirty months construction
• Facility Cost: $525 million
• 7.5 million man-hours worked
• If loaded on gravel trucks at one time, the 1.1 million cubic metres of earth moved in two months would stretch from Caroline to Vancouver
• The top of the 85 meter stack is the same elevation as Roger’s Pass in BC
• All water is retained on site in lined ponds
• Potable Water is piped in from wells north of the Red Deer River
• Peak Employees on Site – 2 500 workers
• Construction Camp had rooms for 1 152 people
• Other trailers in the camp included 224 dormitory trailers and a Recreation Centre created from twelve trailers
• The Camp Kitchen was made up of fifty-seven trailer units and fed between 1 000 and 1 600 workers for lunch during peak construction periods in 1992
• The soup pot in the kitchen was so big, they stirred it with a canoe paddle
• Ninety-one pipe racks and fifty equipment modules weighing from 1 to150 tonnes were transferred by truck from the Cochrane and Nisku assembly yards
• Cranes on site included forty hydraulic cranes (22 to 55 tonnes); seven conventional cranes up to 225 tonnes; one 330 tonne Demag Crawler and one 550 tonne Demag Mobile Crane
• Heaviest single lift was 375 tonnes
• 300 000 metres of power cabling used on the project which, if placed end to end, would reach from Calgary to Edmonton
• 200 000 metres of instrument cable used which, if placed end to end, would reach from Calgary to Lethbridge

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Start Up and Turnarounds

Start-up

• 6 000 applications were received for 100 operation jobs at the gas plant
• Recruiting included completing Grade 12 equivilancy exams and participating in team exercises (including putting together lego helicopters)
• Operations staff was on site February 1992
• Shantz started operating October 1992 using Burnt Timber Sulphur
• Caroline Gas Plant Train I started up March 3, 1993 – seven years after the discovery of the field
• Well 16 located at SW 35-34-05-W5M was the first well started-up
• Caroline Gas Plant Train II is started up May 5, 1993
• The plant has a sulphur recovery efficiency of a minimum of 99.8% which is the best in North America

“Turnaround”

• A Turnaround is a planned Maintenance Shutdown. The 1995 Turnaround at Caroline was extra big to address some of the problems that caused unstable plant performance and flaring since start-up. A Turnaround occurs once every four years.

Turnaround involves:

• Approximately 1 100 people at Caroline
• Usually twenty days or 200 000 manhours
• About 20 million dollars
• 3 000 hours of planning
• Three months of prep work
• Twenty contracting firms involved with the work
• 1.9 million litres of sweetening solution is stored in eighty tanks and cleaned
• The major work (in 1995) was stainless steel coating vessels and replacing carbon steel with stainless steel pipe in some areas of the plant
• The 1995 Turnaround was completed with only two loss time accidents – one was a back strain, the second was stitches because of a hammer defect

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Third Party Gas

With production slowly declining in the Caroline Complex, the Caroline Gas Plant has begun accepting third party gas to keep the plant running at capacity. Hunt Oil is the first company to begin sending its gas to the Caroline Gas Plant. The following is an explanation of its intended operations and its newly constructed inlet facility.

“The Hunt inlet facility came on stream in the early part of June 2003. The facility is designed to handle Swan Hills B pool production of which, in many respects, is similar in composition to the Swan Hills A pool production that it produced and processed into the Caroline plant. The Hunt facility is required just prior to entering the plant as it will:

• Handle the produced water, as the plant is not configured to handle significant volumes of sour water.
• Separate the gas and condensate, as there is a separate header for each at the plant inlet.
• Re-compress and conserve the solution gas from the produced water to ensure flaring is minimized.

The inlet facility is currently designed to handle approzimately 1 000 e3m3/d of raw gas which would equate to about 10% of the current plant capacity.”

Thanks to Swade Holowatuk from Hunt Oil for providing this information.

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