Hi guys! Today we're going to do a short introduction to hydraulic fracturing.
If you are new to oil and gas industry or you just want to learn the basics about
hydraulic fracturing this video is for you. Hydraulic fracturing
or fracking how sometimes it is called is a very popular well stimulation
method which is often used on many newly drilled wells. Fracturing basically means creating small
fractures information that help hydrocarbons like oil and gas to flow more easily into the wellbore.
This is usually achieved by injecting the fluid at high pumping pressures into the wellbore
in order to break the formation and create the high permeability fractures in the well.
Fracturing is often performed on a low permeability formations such as shale for example
and oftentimes on formations like shale fracturing can make a huge difference between when it
comes to production and can be a deciding factor between the profitable well and the failure.
So after the well is drilled it's usually a fracked by pumping the fluid at a high rate
into the formation. Fracturing usually consists of pumping the slurry which is a combination of fluid, sand
and chemicals into the well until formation breaks and the fracture is created. To
achieve required pump rate usually more than one fluid pump is required for the job and in some
cases can be more than 15 pumps. Pressure required to create the fracture in the formation depends on the
formation gradient of the zone which is being fracked and those pressures can be
pretty high and that's why for some fracturing preparations a lot of fluid plants are required.
To ensure that the fracture doesn't close after the pressure is decreased when you
stop pumping sand is pumped as well so what happens is these sand particles
they flow with the fluid into the formation and into those fractures and then they settle in those
fractures and when the pressure is decreased sand helps to keep those fractures open and allows
hydrocarbons to continue to flow easily from the formation into the wellbore. This sand is usually
called proppant. The type of proppant used for the job will depend on the type of formation which is
being fracked and the downhole forces. Sand is a common proppant used for a lot of fracturing
operations but sometimes also artificial ceramic beads can be used as well
depending on the formation. If it's really high-pressure ceramic beads might be used
and the common frac techniques are plug and perf and plug and perf basically consists of creating
perforation in the casing fracturing the zone and then putting the plug above this zone
and then creating perforation again fracturing again and putting plug again so basically you use the
plugs to separate each saw from each other and in most cases a wireline is used to run those plugs.
Another popular method is ball drop which is basically
means the well has a ball drop system and
each time you drop the special ball down the well you separate each zone from each other.
The next popular method is sliding sleeve systems and whenever there is a sliding
system in the well usually the coiled tubing is used used for the fracturing operations and it's used to
open and close the sleeves. Now let's take a look at the typical frac equipment. The first thing
you're going to see when you come to the frac location are the fluid pumps. Usually a lot of
fluid pumps are required for the job so you will see probably at least 10 of them. You might also
sometimes see the nitrogen pumps as well depending on what type of fracturing is done. You will also
see a lot of sand trucks coming to the location unloading sand and going back to the sand facility.
Those sand trucks unload the sand into the sand storage which are usually just
large bins that you'll see on location and usually, there is a conveyor belt
going from those large sand storage bins to the blender. The next piece of equipment you
will see is a datavan. Datavan is basically a trailer from which the crew runs the job.
Usually datavan also has satellite which is used to send the real-time frac data
to the client and the frac engineers in the office. Then there is a blender and blender is used to mix
fluid, chemicals, sand together before this slurry goes into the well.
Sometimes you will also have the hydration unit which is used to hydrate the dry chemicals like
for example, dry friction reducer before it's hydrated and pushed into the
blender and lastly you'll see some iron trucks which are used to carry the pumping iron.
Now let's take a quick look at the fluids and chemicals used in fracturing.
Additionally to sand various chemicals such as friction reducers, gelling agents and biocides
are used for the operations. There are also a lot of different other specialized chemicals but today
we're just going to take a look at the most common ones. So friction reducers are used to lower the
pumping pressure during the job and this helps to save fuel and allows to pump at a higher rate
and sometimes friction reducer is also used to assist the fluid with carrying the
proppant downhole. Depending on the frac, gelling agents are used to increase the viscosity of the fluid in
order to improve its sand carrying capacity. Usually when the gelling chemicals are used
breakers will be added as well to the fluid so that later after the frac those breakers can
break down the gel and prevent any type of formation damage that can
lower the production from the well. Biocides are often used to kill the bacteria in the water
which can potentially corrode the equipment and also create different by-products in a well
that might create issues later down the road. A large amount of fluids is required for
every frac operation and oftentimes water is is the most common fluid
used for frac operations. Usually the water is brought to location and
stored in specialized pools called C-rings on location before the frac starts. If it's a
small frac job the fluid can also be stored in 400 barrel tanks instead of C-rings
and freshwater is usually preferred for frac operations because it doesn't interact with
any chemicals and when you pump the fresh water you will usually have lower pumping
pressures versus pumping brine or recycled fluid but in many cases
fracturing is done by mixing the freshwater with recycled fluid just to lower the cost
because many times it's not easy to get the fresh water depending on where you fracturing the
well and freshwater is expensive. That's why oftentimes the recycled water from other wells
is used and fresh just added to lower the salt content and make the water usable for the frac
and in addition to water sometimes acids are pumped as well. Usually just to prepare
the perforations and the near-wellbore formation for the frac.
So guys this is just a basic introduction to the fracturing, hopefully you learned something
new please don't forget to subscribe and I'll see you guys next video. Bye!