Nitrogen is often used for pipeline testing and maintenance within industrial, chemical and oil refining plants. Some of the applications for nitrogen include purging, pigging, inerting, drying and pressure testing. The nitrogen has very low moisture content with a dew point typically around -90°F, making it ideal for these applications while ensuring long term preservation for idled equipment. Typically liquid nitrogen is brought to the site via cryogenic transport trailer, then pump and vaporized, for injection into pipelines and vessels. The pump and vaporization equipment is trailer-mounted and available as a rental, making it well-suited for temporary maintenance operations.
The gaseous nitrogen can be supplied at pressures from atmospheric up to 15,000 psig. A variety of different vaporizer technologies are available depending on the flow rate requirement and available heat sources. For lower flow rates the vaporizers are based on recovering heat from flameless heat sources on the trailer such as engine coolant and exhaust gas. For higher flow rates the vaporizers are based on combustion of diesel or natural gas.
Exploration and production of oil and gas requires an incredible amount of energy to power drilling rigs and pressure pumping fleets. The majority of drilling rigs are electrically powered with multiple generators, called gensets, providing up to 4,500 HP to the rotary table, mud pumps and drawworks. These gensets can be powered by natural gas in a dual-fuel arrangement when blended with diesel or in a dedicated gas-only arrangement. Pressure pumping fleets are mechanically or electrically powered by reciprocating engines or gas turbines. These fleets have a combined power up to 65,000 HP for driving high pressure hydraulic fracturing and acidizing pumps. These fleets can easily be converted to dual-fuel and gas-only arrangements.
The advantages of displacing diesel with natural gas come in both reduced emissions and cost. Recent emissions regulations in North America and Europe have led manufacturers to the development of dual-fuel and gas-only engines. Natural gas as fuel is one such development which reduces NOx, SOx, CO2 and particulate matter emissions. In addition, natural gas is so abundant in oil and gas fields that it is often flared due to lack of pipeline capacity. This means the natural gas cost is very low compared to diesel. Furthermore, harnessing the energy by using it for power generation is a much better use than simply flaring the gas.
A variety of petrochemicals such as ethane, ethylene, propylene and ammonia are most economically stored and transported in their cryogenic liquid state. Most processes require these petrochemicals to be vaporized back to a gaseous state before they can be used. Ethane is a common byproduct of oil and gas production and is primarily used as a feedstock for production of ethylene through steam cracking. Ethylene is a feedstock which is used for production of polyethylene plastics, ethylene oxide, ethylene dichloride, ethylbenzene and other chemicals. Propylene is a common byproduct of steam cracking in oil refining and is mainly a feedstock for polypropylene and propylene oxide production. Lastly, ammonia is a widely-used feedstock in the production of fertilizer, urea, household cleaners and other nitrogenous compounds.
The exploration and production sector of the oil and gas industry utilizes nitrogen frequently for a number of operations throughout the life of an oil and gas well. During the workover and completion operations, gaseous nitrogen is pumped into the well to displace well fluid in the casing which has a heavier density than the nitrogen. This is called nitrogen lifting because it induces flow from the wellbore. Similarly, nitrogen is mixed with cement and pumped into the annulus, creating a foamed cement with a lighter density and better resistance to stress cracking.
Nitrogen can be used for other types of production stimulation when utilized in hydraulic fracturing and acidizing. The nitrogen is mixed in varying amounts with water or acid and sometimes a foaming agent depending on the type and depth of the formation. For shallower formations, foam makes it a good proppant carrier while reducing the amount of water and chemical loading.
Our NEW direct fire vaporizer runs on "clean burning natural gas," greatly reducing the diesel emissions of conventional fired vaporizers.