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. The advanced liquid nitrogen techniquespioneered in the Gulf Coast of the United States in 1959 have experiencedsignificant growth in the past four years. 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. 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. These techniques have been field-proven inthousands of jobs and are supported by research results.
Industry has developed nitrogen procedures to:
Provide uncontaminated drill stem test samples, reduce misruns and setpackers.
Bring in wells without swabbing and its inherent hazards - day ornight.
Enhance 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.
Boost hydraulic perforating stream penetration up to 300 per cent, andsimplify "dry" gun perforating.
Quickly droll mud weights to combat lost circulation while drilling andcementing.
Combat paraffin and corrosion and increase inhibitor treatmenteffectiveness.
Prevent downhole explosions when air drilling, and reduce formationcontamination by using nitrogen as a drilling fluid.
Today, thanks to the missile age, the oil industry is served by liquidnitrogen units that are equipped with positive displacement "cryogenic" pumps.The cryogenic (super-cold) pumps were developed to handle fluids as cold as-350°F, which are common in the missile industry. With the introduction of thefirst liquid nitrogen unit in December, 1959, in Texas, and the use of thecryogenic pump, the versatility of nitrogen for oilfield uses has greatlyincreased.
