{{Dicdef
Repressuring is a common method of increasing the pressure inside of a crude
oil well
An oil well is a drillhole boring in Earth that is designed to bring petroleum oil hydrocarbons to the surface. Usually some natural gas is released as associated petroleum gas along with the oil. A well that is designed to produce only gas ma ...
in order to increase the output of the well. Pumping crude oil from a
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including control ...
causes its pressure to drop, which further reduces pumpability. Returning the natural gas or other inert gases to the oil well increases the pumpability of the crude present inside the well by decreasing its
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
and
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...
. In one instance, slower rate of oil production and recycling of natural gas at 9.6
MPa
MPA or mPa may refer to:
Academia
Academic degrees
* Master of Performing Arts
* Master of Professional Accountancy
* Master of Public Administration
* Master of Public Affairs
Schools
* Mesa Preparatory Academy
* Morgan Park Academy
* Mo ...
enabled a net recovery of 70% of the oil originally present.
Although recovery can be increased even by repressuring with air, air is seldom used because it causes an inferior quality of product. Instead carbon dioxide or natural gas itself is used so as to not only increase the recovery from the oil well but also to maintain the high quality of the product.