In today's video, we're going to take a look at how nitrogen is used in oil gas operations.
Nitrogen is commonly used both for upstream and downstream oil gas operations because it's a
neutral gas and this is very important when dealing with combustible fluids and gas that
are commonly found during the oil gas operations.
It also doesn't react with metals to cause corrosion like oxygen and that's the reason why nitrogen is used instead of just air.
And in addition, nitrogen is non-toxic.
Nitrogen is a highly compressible gas and it's usually stored under pressure and transported to the location in specially designed nitrogen pumps and tankers.
Nitrogen is a very abundant gas and the air we breathe is made up of about 78 percent nitrogen
and that's the reason why it's relatively easy and cheap to extract nitrogen from the air.
There are several ways that can be used to extract nitrogen from the air.
The first one is a fractional distillation and consists of cooling air and then breaking it down into different gases based on
their boiling point.
The second method is using the membrane.
The air is passed through especially special fibers that can separate it into different gases based on their speeds.
This is usually a slow process and the purity of the nitrogen gas depends highly on the membrane used.
The last method to extract the nitrogen from the air is called pressure swing absorption.
And it works by pushing the compressed air through the specially designed equipment
with absorption material inside that absorbs oxygen but lets nitrogen pass through.
Now let's take a look at the most common nitrogen operations that we can encounter in the oil field.
First, we have a well kick-off.
Some wells have a very low bottom high pressure and when the wellbore is full of heavier fluid the well might stop producing because the hydrostatic pressure is
higher than bottom high pressure.
Nitrogen is often used to lower the pressure of the hydrostatic column of the fluid in the wellbore by displacing the heavier fluid from the well and bringing the well
back to production.
Sometimes coil tubing is used to pump nitrogen to the bottom of the well and lift the wellbore fluids.
Nitrogen is also used for pipeline, plant and equipment purging
to remove oxygen and various hazardous combustible
gases and chemicals.
This is often done to prevent rusting during the non-operating time.
Next, we have a pipeline pigging and this involves pushing a pig with nitrogen to clean the pipeline
and remove any wall buildups.
Nitrogen is also used for wall drilling intervention operations.
When working on the low-pressure wells, nitrogen can be pumped along with the fluid to keep the hydrostatic pressure lower than the bottom hole pressure to avoid the loss of returns in the well
Nitrogen is also used for fracturing operations especially when fracturing lower pressure
formations and this nitrogen is pumped to energize the formation.
This helps with the fluid flow back post frack and also decreases the amount of fluid required for the frack.
Nitrogen is also commonly used after coiled tubing operations to remove the fluid from the coil
before the coiled tubing unit can travel.
This decreases the weight of the coil and prevents the
the potential freezing during the winter operations as well as it slows down the corrosion especially
if coil is not going to the next job right away and it's stored in the shop.
Nitrogen can also be used for pressure testing various oil field equipment
but one challenge with nitrogen is that it's a gas and it means it's highly compressible so
nitrogen is not an ideal fluid for pressure testing when working with higher pressures.
And oftentimes
water is used instead.
And lastly nitrogen is used for enhanced oil recovery operations
and it's done by injecting nitrogen into the injection well and this increases the reservoir
pressure and helps to increase the production from the producing wells.
So these are some of the common nitrogen operations that you might encounter in the oil field.
Thanks, guys for watching this video and I'll see you guys later!