Such is its abundance and properties, nitrogen is a key product throughout various markets and applications. Steelmaking and metal cutting, food processing and freezing, pulp and paper processing, glassmaking, oxyfuel combustion applications, medical procedures, and electronics manufacture all rely on nitrogen in some form or capacity.
Whether it’s for its unique properties in blanketing and inerting applications, or its use as a refrigerant in the grinding of plastics and freezing of food products, the role of nitrogen is essential.
A core end-use of nitrogen is in the oilfield, an application that has never been more prominent. Since the shale oil and gas boom, hydraulic fracturing has spiked – with revived and new interest in enhanced oil recovery (EOR) involving either nitrogen or carbon dioxide (CO2). This is nowhere more relevant than in the US, where the ‘shale gale’ has been blowing through the country’s energy sector in recent years.
Even in the midst of a collapse in oil prices and struggling energy markets in the last 18 months, the role of gases like nitrogen arguably takes on greater significance; the emphasis during such times is to maximise operations and extract every last drop of oil, with industrial gases and equipment at the heart of optimising upstream and downstream activities alike.
Shale gas, trapped within massive shale formations, has become an important source of natural gas in the US and interest has spread to potential gas shales across the rest of the world. In 2000, shale gas resources provided less than 1% of total US natural gas production, but by 2010 shale gas accounted for over 20% and the Energy Information Administration (EIA) has previously predicted that by 2035, 46% of the US’ natural gas supply will come from shale.
The use of nitrogen and CO2 overcomes and mitigates many of the challenges associated with traditional water-based hydraulic fracturing fluids required to exploit this shale gas, by reducing the high volumes of water, chemicals and even proppant. Nitrogen can therefore provide a better approach to increase oil and gas production from tight or water sensitive formations, as well as unconventional reservoirs such as shale, tight sands and coal bed methane. It has also proven effective for well stimulation of shallower reservoir environments.
When injected into gas and oil wells, these solutions are able to enhance hydrocarbon production rates and yield improved long-term economic recovery over the life of the well – as well as minimising environmental damage by limiting water retention and damage to rock formations.
From upstream operations like exploration and extraction to downstream refining, nitrogen is foremost among the industrial gases, equipment and services are at the core of the global oil industry.
Upstream activities include exploration and extraction, and increasingly fracking; as with shale gas, liquid nitrogen and carbon dioxide are among the industrial gas products used to enhance oil production rates and yields, while also lowering total costs. Many of the gas industry’s major players have been seen to capitalise on this demand for nitrogen product in oil and gas services in recent years.
2013 saw Air Liquide Industrial US acquire Progressive Resources (PRI), an Oklahoma-based supplier of liquid nitrogen and cryogenic storage and distribution systems and related services to the oil and gas services sector. Bulk liquid nitrogen is provided by PRI to customers for a variety of oil and gas well site applications that include well stimulation, pressure testing, drill stem testing, coil tubing operations, and cleaning and jetting. Likewise, Praxair, Inc.’s acquisition of UK-based Dominion Technology Gases Investment Limited (Dominion) uniquely positioned Praxair to provide industry-leading products and services to an expanded base of high-value customers in the global offshore oil and gas market.
The company also started up a new packaged gas fill plant in Bismarck, North Dakota in 2014, significantly increasing its cylinder gases capacity in the Bakken shale oil formation, while fellow gases company Matheson positioned itself to cater for growing nitrogen demand in the area with the construction of a new ASU in Dickinson, North Dakota, also in 2014. Just months before these developments, Air Liquide commenced operations at a new nitrogen production plant in Tioga, North Dakota as it sought to further support growth in drilling operations in the oil-rich Bakken reserves. Since then, activity involving nitrogen has included:
Enhanced oil recovery
Nitrogen plays a central role in enhanced oil recovery (EOR), and there are understood to be five main EOR applications that utilise nitrogen, including pressure maintenance, miscible displacement, immiscible displacement, gas assisted gravity drainage, and mixed gas, which increases reservoir reserves. Nitrogen is also used as an energised fluid to fracture shale or other unconventional formations to produce tight gas and oil reservoirs.
Perhaps nitrogen’s best understood role in EOR is when it is pumped underground with high pressure. This nitrogen injection increases the pressure in the oil wells so that fossil resources can be more easily recovered and yields significantly improved. This technology has helped make the Cantarell oil field on the Gulf of Mexico more efficient – a project that Linde was central to.
”In the first year of nitrogen injection, Linde explained to gasworld, the flow rate rose by 60% after nitrogen was pumped in…”
Cantarell is one of the world’s largest oil fields that is located in the sea. At the same time, it is Mexico’s most important crude oil supplier, with around one third of Mexico’s total production output of crude oil derived from this one field. Some experts, however, have suggested that in some years in the future, the oil reserves here may be completely exhausted; this is where nitrogen has come to the fore as a solution in postponing this juncture and maximising the return from the field’s reserves.
To raise the pressure in the field and ensure the flow of oil, large amounts of nitrogen must be pumped in, to which end a Linde complex of no less than five ASUs has met – and continues to meet – this demand. In the first year of nitrogen injection, Linde explained to gasworld, the flow rate rose by 60% after nitrogen was pumped in. Could there be a better example of nitrogen’s value in the oil and gas sector?