Saudi Aramco has launched the Kingdom's first carbon capture and sequestration (CCS) project and CO2 Enhanced Oil Recovery (EOR) project at its 'Uthmaniyah and Hawiyah NGL facilities. The CO2 EOR project is the largest CCS project in the Middle East.
The pilot project, comprised of a CO2 capture plant in Hawiyah and an enhanced oil recovery project in 'Uthmaniyah oil field, demonstrates the company's commitment to lead by example through environmental stewardship and citizenship. The CO2 Capture project at location will inject compressed CO2 into flooded oil reservoirs as a mechanism for CO2 storage; and the injection of CO2 under high pressure will simultaneously enhance oil recovery. For these reasons, carbon capture and storage is considered a win-win technological solution.
Carbon management now is an integral part of our business. Since the company established its Master Gas System in the 1970s, CO2 emissions have been reduced significantly. Led by the EXPEC-Advanced Research Center (EXPEC ARC), our carbon management technology road map includes many focus areas with a main goal of developing the required technologies to reduce CO2 emissions.
“This breakthrough initiative demonstrates that we, as an industry leader, are part of the solution to proactively address global environmental challenges,” said Amin H. Nasser, the company's acting president and CEO. “Saudi Aramco is carrying out extensive research as part of our Corporate Carbon Management Technology Road Map, enabling us to lower our carbon footprint while continuing to supply the energy the world needs.”
Environmental stewardship has long been a hallmark of Saudi Aramco's business, with the company's environmental protection policy formally established in 1963. Effective carbon management is one of the many strategies that Saudi Aramco employs to meet the goals of reliably supplying energy safely and responsibly. Reducing gas flaring, introducing zero-discharge technologies at well sites, and implementing a comprehensive water conservation policy at all plants and communities are also amongst the company's carbon management efforts.
“It is indeed a very proud moment for EXPEC ARC and the team that has been spearheading the effort over the past several years to conceptualize, generate research data, design and implement the pilot project in 'Uthmaniyah,” said Waleed Al-Mulhim, EXPEC ARC manager. “The project has been supported by several Upstream and Downstream departments. It has been a concerted team effort to bring it to fruition.”
Ali Al-Meshari, chief technologist for Reservoir Engineering at EXPEC ARC and coordinator for the Carbon Management Team, said the culmination of the pilot project is a significant achievement.
“It will have a measurable impact on reducing overall CO2 emissions. It will inject ~800,000 tons of CO2 every year, and establish a monitoring system to measure how much of that CO2 remains sequestered underground,” said Al-Meshari.
Constant monitoring
Sunil Kokal, who led the CO2 EOR project team and is the Focus Area Champion of CO2 EOR research at EXPEC ARC, said the project includes a row of four injector wells and four producer wells, and another two observation wells for monitoring and surveillance. It is estimated that up to ~40% of the injected CO2 will be sequestered permanently in the reservoir. The project also aims to enhance oil recovery beyond the more common method of water flooding. The main objectives of the pilot are determination of how much CO2 remains sequestered or stored in the reservoir, estimation of incremental oil recovery (beyond water flooding), addressing the risks and uncertainties involved, including migration of CO2 within the reservoir, and identifying operational concerns.
The project will use 40 million standard cubic feet per day (scfd) of CO2 that will be captured and processed at Hawiyah NGL Recovery Plant and piped 85 kilometers to 'Uthmaniyah field for injection.
“The CO2 will be injected into four injector wells in a water-alternating-gas mode,” said Kokal, noting that the CO2 and water will be injected at around 2,800 pounds per square inch (psi) into alternate injectors and switched every month.
First in the region
An elaborate monitoring and surveillance program has been developed for the pilot project to obtain data and evaluate its performance. The main objectives of the monitoring program include the migration of CO2 within the reservoir, assessing key risks and uncertainties, understanding recovery mechanisms, identifying operational issues, and building public confidence in the first CO2 sequestration project not just in the Kingdom but throughout the GCC region. Monitoring will take place with a range of methods, including seismic monitoring, electromagnetic surveys, borehole and surface gravity, and inter-well tracer tests.
“Many new technologies are being implemented, some for the first time in the Kingdom, some for the first time in the region, and many for the first time in the world” said Al-Mulhim.
At the end of the compression process, the CO2 is compressed to 3,500 psi, and is in a supercritical phase, like a dense fluid. It is in this state that the gas is transported via pipeline to the North 'Uthmaniyah area of the Ghawar field for injection at 2,800 psi. Processing of the Enhanced Oil Recovery fluids is done at 'Uthmaniyah GOSP-7.
“The compression process takes place in a 7-stage internally geared compressor — the largest such compressor to be used in the company,” said Abdullatef Al-Mufti, chief commissioning engineer at HNGL. After the 5th stage of compression, the CO2 is still considered “wet,” and so it is routed to a Gas Dehydration Unit for processing, before being reintroduced into the compressor for stages 6 and 7.
Getting the project up and running was complicated by the fact that new contractors and new technologies were being deployed. Mohammed A. Suwaiyel, lead project engineer with Southern Area Projects Department, said the key to success was the collaboration of all departments in completing the project — all conducted during normal operations at Hawiyah and 'Uthmaniyah.
“The project has completed 11 million construction man-hours with zero incidents,” said Suwaiyel.
After commissioning of the CO2 Capture Unit at Hawiyah NGL last month, liquefied CO2 is now being sent to 'Uthmaniyah field for injection. Nearby at 'Uthmaniyah GOSP-7, a new standalone high pressure production trap (HPPT), a new compressor and associated facilities for handling the high concentrated CO2 production streams have been built. This is where the monitoring of produced fluids will take place, and where Saudi Aramco takes extra steps to ensure as much CO2 as possible remains sequestered underground.
As the site for injection, Southern Area's 'Uthmaniyah field was key to the project. SAOO Technical Services Department coordinated and interfaced the construction of the facilities at both ends, ensuring that the CO2 can be injected safely. Several departments are contributing to the ongoing production-related activities that include logging, testing, and evaluation.
At 'Uthmaniyah GOSP-7, engineers will be monitoring the project to ensure that the CO2 remains sequestered underground. For this reason, GOSP-7 has been retrofitted to include new facilities, such as a three-phase separator, CO2 compressor train, and a flare system, to handle recovered fluids for further processing.
Out in the field, 10 wells specifically drilled for the EOR project have been equipped with downhole monitoring sensors to provide full surveillance of reservoir parameters during the project period. All 10 wells are connected and equipped with real-time flow measurement devices, automated and remotely-controlled choke valves to ensure full accessibility and control over the project area.
Over the next three to five years, the pilot project will be studied by engineers in the field and at EXPEC ARC. Lessons learned from this project will be utilized at other facilities and oilfields around the Kingdom, helping to maintain Saudi Aramco's position as the world's most productive and reliable provider of energy.