LN can cool concrete by more than 12☌ (20☏) and has been used to obtain concrete with a placing temperature as low as 2☌ (35☏). In the event that too much LN is injected into the mixing drum, the mixing drum can become damaged or even ruptured. The rotation of the mixing drum is essential when the LN is injected to the concrete to prevent nitrogen pools from accumulating within the mixer. Typically, when the lance is inserted into the mixer, it appears as though there is a release of toxic fumes, but in reality, this is just inert nitrogen and water vapor boiling off.
The entire sequence of inserting the LN into the mixer is computer controlled to assist the operator in positioning the truck properly and when the cooling is complete. The flow of LN through the lance is controlled by a pneumatically operated ball valve. Typically, the lance can move vertically and horizontally, to allow the operator to position it correctly. LN is injected into the mixer with a lance, which can move in and out of the ready-mix truck using a pneumatic cylinder. Typically, LN is injected directly into the mixer without making changes to the mixer itself. LN is produced by compressing and cooling nitrogen gas to a point below its evaporation point of about −196☌ (−320☏). LN can be set up at a project or plant within a few days and can supplement other cooling methods to achieve a reduction in concrete temperature when necessary ( Beaver, 2004). LN can be stored at the batch plant or on the project site, and if used on the project site itself, then repeated cooling of the concrete and greater control of the concrete temperature are possible. LN is injected directly into the batch water storage tank, aggregate, or mixer via lances to lower the temperature of the concrete as much as practical without freezing. LN is an inert cryogenic fluid with a temperature of −196☌ (−320☏). LN has also been used as a method for cooling concrete for over 20 years. Surana, in Developments in the Formulation and Reinforcement of Concrete (Second Edition), 2019 6.3.5 Liquid nitrogen for cooling concrete
Prevent downhole explosions when air drilling, and reduce formationcontamination by using nitrogen as a drilling fluid.C. Quickly droll mud weights to combat lost circulation while drilling andcementing.Ĭombat paraffin and corrosion and increase inhibitor treatmenteffectiveness. Provide uncontaminated drill stem test samples, reduce misruns and setpackers.īring in wells without swabbing and its inherent hazards - day ornight.Įnhance the benefits of stimulation treatments and force spent acid andfrac fluids out of the formation quickly and more efficiently, thus reducingwell bore damage and increasing productivity.īoost hydraulic perforating stream penetration up to 300 per cent, andsimplify "dry" gun perforating. Industry has developed nitrogen procedures to: These techniques have been field-proven inthousands of jobs and are supported by research results. Liquid nitrogen, pumped at pressures of upto 10,000 psi, is forced through a gasifying heater and the colourless, odourless inert gas is injected into the well to perform a variety of valuable, safe and time-saving functions. Such techniques are not confined tojust one or a few applications but have become intertwined with every aspect ofwell development and have made obsolete many oilfield practices previouslyemployed throughout North America. The advanced liquid nitrogen techniquespioneered in the Gulf Coast of the United States in 1959 have experiencedsignificant growth in the past four years. Nitrogen is not a cure-all, but the results of field and laboratory workthat have evolved during recent years support its use as a valuable aid indrilling and completion operations.