Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Home > Gas reinjection
Gas reinjection is the reinjection of natural gas into an underground reservoir, typically one already containing both natural gas and crude oil, in order to increase the pressure within the reservoir and thus induce the flow of crude oil. After the crude has been pumped out, the natural gas is once again recovered. Actually some of the wells found around the world have heavy crude. The basic difference between light crude and heavy crude is its viscosity and pumpability - the lighter the crude the better the characteristics. An intermediate crude is also found in wells, which are nothing but crudes with a viscosity intermediate to those of light and heavy crudes. Anyway, recovery of all the hydrocarbons in a well is impossible (certainly in case where the well contains crude and not just natural gas). This problem is all the more prevalent in case of heavy crudes, which can be recovered only to an extent of about 50% of the total crude in the well. The same for a light crude can be as high as 75-80% under favorable conditions. Recycling of natural gas or other inert gases causes the pressure to rise in the well, thus causing more gas molecules to dissolve in the oil lowering its viscosity (keeping in mind that the gas so used has a lower density and viscosity than the oil present) and whereby increasing the wells output. Air is not suitable for repressuring wells because they tend to cause deterioration in the product so obtained. For this very purpose carbon-di-oxide or natural gas itself is used to repressure the well. This very term of 'gas-reinjection' is also sometimes referred to as repressuring--the term being used only to imply that the pressure inside the well is being increased to aid higher recovery.
Read more »