Climate change and oil and gas operations' role in it are often delicate topics when oil and gas professionals meet at industry conferences.
Industry's official line has been that, even among themselves, climate scientists debate the existence and causes of global warming; so why should oil and gas companies spend billions and change their operations for such dubious goals?
This line, reply scientists, ignores the fact that most climate scientists accept the fundamentals of global warming, debating only its extent and specific mechanisms. The earth is warming, they say, and human activity since the Industrial Revolution is the main cause in producing ever-higher levels of greenhouse gases, mainly carbon dioxide.
Less well known—and certainly less often touted at oil and gas gatherings—are efforts by many in industry to curb the flow of CO2 into the atmosphere.
In fact, such efforts dwarf those of the power industry, according to David Weeks, KBR's technology manager for gas processing and carbon capture and storage, speaking to the recent Gas Processors Association Convention in New Orleans.
Weeks described how most CCS projects seek to demonstrate one or more links in a CCS chain: CO2 capture→CO2 compression→CO2 dehydration→CO2 pipeline→CO2 storage and monitoring.
Industry efforts
The Global CCS Institute in Canberra, Weeks cited, counts 74 CCS projects "at various stages of development worldwide, with 25 in the US and 21 in Europe." Of today's eight operating CCS projects, he said in April, six are "associated with gas processing plants," with two more in execution.
Space limits listing here all the projects Weeks named, but some are:
• In Norway, on Sleipner West, operator Statoil began in 1996 using amine absorption to reduce CO2 to 2.5% in produced natural gas, from 9%.
The company also injects 1 million tonnes/year of CO2 into the Utsira formation, 1,000 m below the seabed.
That process has avoided more than 10 million tonnes of CO2, said Weeks, equivalent to all the CO2 emitted by all cars in Norway over 2 years. He also said the Norwegian CO2 tax of $50/tonne makes CCS cost-effective.
• The Mongstad refinery in Norway plans to employ post combustion to capture 100,000 tpy of CO2 with amines and chilled ammonia.
The capture plants, said Weeks, operate independently on two sources of flue gas from the refinery: 1. Combined heat and power unit's gas-fired power generation: about 3.5% CO2. 2. Residual catalytic cracking unit's composition, which is similar to coal-fired power generation: about 13% CO2.
Coincidentally, an inauguration was set for May 7.
• The Snohvit LNG offshore gas project off Norway began in 2008 to reduce to 50 ppm (vol) for liquefaction the produced-gas content of 5–8% CO2, also by amine absorption. The project injects 700,000 tpy of CO2—equal to emissions of 330,000 automobiles—into storage in the Tubasan sandstone 2.6 km below the seabed.
The project has demonstrated subsea pipeline transport and storage in as much as 330 m of water.
• Since 2004, the In Salah gas project in Algeria, operated by Sonatrach, BP, and Statoil, has been reducing CO2 in produced natural gas to 0.3% from 6.6%, with amine absorption.
The process compresses CO2 to 203 barg and dries it via triethylene glycol before injection into three, 2,000-m deep wells 14-20 km from Krechba central processing. As much as 1.15 million tpy are being injected in a saline aquifer.
• Australia is home to probably the best known CCS project, Chevron's Gorgon LNG, which targets start-up in 2014.
The plan is to reduce CO2 to 50 ppm (vol) for liquefaction, as on Shohvit, and compress the CO2 to about 200 barg. No dehydration is planned.
The effort will capture about 5 million tpy of CO2 into a saline aquifer.
Responsible delivery
Exactly what these projects may say about industry's attitude toward global warming demands another column.
But I've covered midstream companies since before we called them that. What strikes me is that again, men and women who work daily to ensure fossil energy moves from production to market are also using their considerable technical skills and imaginations to do that responsibly, whatever the political climate.
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