Electric power can be regarded as the lifeblood of oil and gas sites. As much as technology has evolved, enabling engineers to assess and monitor the performance and efficiency of key equipment remotely, the fundamental requirement for a reliable, trustworthy power source remains as relevant today as it was when the industry was evolving and the nations of the Arabian Gulf began to exploit their vast reserves more than 60 years ago.
Today, while technology and innovation across many sectors of the upstream industry has developed, the extraction of oil and gas, as well as its transportation, has also pushed past old frontiers into new territory. Many of the current significant hydrocarbon finds are offshore, or at vast depths, requiring effective capture and transportation. From pumping oil or water to driving compressors or liquefied natural gas trains, power generation is the common denominator.
One of the long-established power sources over many years is the diesel-powered generator. These “gensets” have always been suitable for deployment on shorter duration projects partly due to their movability, but technological advances, the price of diesel and more stringent emissions policies have helped to dull their attractiveness.
Pierre Leretz, president, lead division manager, industrial automation at power and heavy electrical equipment specialists ABB is in no doubt that diesel gensets look increasingly outmoded. “The fuel cost optimisation, and environmental considerations, have opened more options to upstream oil and gas companies. As an example, better utilisation of flare gas, zero flare gas, has opened a whole new era for power generation.”
New technologies have enabled operators to potentially make dramatic savings by utilising the natural gas often previously burnt off, or flared, at the wellhead, to generate power to run a variety of applications and processes from pump jacks to artificial lifts.
Some exploration and production (E&P) operators have seen costs fall by 70% to 80%, while the ability to channel the excess gas into rich-burn engines, alongside the elimination of the need for diesel altogether, has made major reductions to emissions.
Vivek Chandra, a gas expert and CEO of Texas LNG, is forthright about the role diesel gensets should play in powering oil and gas fields. “Diesel should have been relegated to the ‘fuel of yesterday’ for power generation a long time ago. Power generation from diesel should be for special and temporary circumstances only – and where there is no gas infrastructure. It has a high relative cost, is noisy and is best used for transport.”
Mokhtar Fawaz, vice president turbomachinery and process solutions at Baker Hughes, a GE Company, still feels diesel gensets have a role in the Middle East although he identifies “diesel gensets being most in demand from the construction, retail and telecom sectors” rather than the hydrocarbon industry.
He also feels that more advanced gensets, which have increased performance reliability and efficiency, and have the flexibility to work across the “rigours of various applications” are proving popular within the region. However, Fawaz also believes that the issue of cleaner fuels and reduced emissions is still a prominent factor.
“We see a significant shift in the approach of the region’s oil and gas majors, who understand the long-term value of investing in more efficient and environmentally-cleaner technology. Gas brings several advantages – from more efficient use of land, capital and fuel to securing faster, cleaner and flexible power.”
Another increasingly popular power option for oil and gas sites is high-voltage direct current (HVDC) electricity, which uses direct current for the transmission of power, as opposed to the more accustomed alternating current (AC).
Pierre Leretz of ABB sees benefits on a number of levels, “Recent projects for offshore power demand forecasting have systematically put in competition, traditional power generation choices versus HVDC solutions. HVDC solutions have come out more competitive, less footprint, more environmentally friendly and safer for the operation and people. All good reasons to prefer this new technology.”
HVDC solutions are well suited to providing power to remote or offshore facilities. Typically, offshore platforms would generate their power by burning either natural gas or diesel in their own on-board turbines or generators but HVDC uses a long distance power cable transmission system to supply electricity from the mainland.
Environmentally, this then nullifies the potential carbon dioxide emissions that would have been generated from burning gas or diesel, while various studies have indicated that HVDC, especially over longer distances, is more reliable and efficient than AC, as well as having reduced capital costs.
One area where diesel gensets remain popular is in projects with fairly short timelines. This also makes them popular during oil price downturns when E&P operators are especially cautious regarding overheads and profit margins, and so they turn to the power generation rental market in which diesel gensets have been habitually popular.
But in this segment too, newer, more efficient and cleaner alternatives are becoming increasingly attractive. Aero-derivative gas turbines are relatively lightweight, portable and can be installed and commissioned in under a fortnight. This may represent a ponderous process when compared to the swiftness of accessing a diesel-powered generator, but over time gas turbines will prove significantly cheaper due primarily to the cost of diesel, while there will not be the thorny issue of emissions targets.
Based on aircraft turbine engines, aero-derivative turbines can withstand the harsh conditions often experienced within the oil and gas industry and are used across many parts of the energy value chain.
Looking to the future, the latest cutting edge technologies suggest that power generation solutions at the oilfield could become even more environmentally friendly. In Oman, the ambitious ground-breaking project between Petroleum Development Oman and GlassPoint, which uses solar power to heat water released when oil is extracted to generate steam, which, in turn, is then pumped back into the ground to release even more oil, perhaps suggests the way forward.
The use of renewables to help facilitate the extraction of fossil fuels may have sounded like an uneasy fit at the start of the millennium, but in reality it indicates the growing maturity, awareness and advancement of the hydrocarbon sector. No longer will tens of billions of dollars worth of natural gas simply go up in flames as a worthless by-product of oil extraction.
