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2.3 Hydraulic Fracturing Step by Step
Hydraulic fracturing is not a new technology. As mentioned earlier, it was invented
in 1947 and has been in use for more than 70 years. Fracking operations are carried
out by what the O&G industry calls “service companies.” These include Halliburton,
Schlumberger, Baker Hughes, CalFrac, FTS and others. Many of these companies
offer wellbore cementing, well logging, matrix stimulations, and other completion
services in addition to fracking.
Hydraulic fracturing operations are performed by highly trained, experienced
crews using specialized equipment. Like many other oilfield workers, frack crews
work around the clock, 7 days a week on “tours” that last until the job is completed.
Fracking is all they do, and they move themselves and their equipment from well
pad to well pad, often on tight schedules due to a shortage of crews or to avoid the
onset of bad weather.
The notion promulgated by some O&G opponents that the people who perform
fracking are careless, clueless, or irresponsible couldn’t be further from the truth.
Many of these folks are engineers holding at least Bachelor’s degrees, some are
licensed Professional Engineers (PE), and most have years of relevant experience.
The people who design, manage and monitor the actual hydraulic fracturing job on
site are all educated professionals. Hydraulic fracturing is an expensive and logistically complicated process, and there is plenty of competition for business. Frack
crews strive to complete the stimulation according to design specifications, maintain the fracture within the target zone, and use the minimum volumes of water, sand
and chemical additives necessary to create the desired frack. Mistakes do happen,
but companies who waste materials or frack into non-productive zones cost the
operating companies too much money and don’t last very long.
The logistics are formidable – all of the needed materials, sometimes including
the water have to be transported out to well locations, which are often in remote
areas. Everything needs to be inventoried and prepared for use, and then transported
to the next location after the hydraulic fracturing operation is completed. Many of
the fracking operations are done in “stages,” which means that multiple, individual
fracks take place at different zones within a single well. In the case of shale production where directional boreholes are used, there may be a half dozen or more wells
on a single pad, and all of them require staged fracks.
When wells are drilled, lengths of steel pipe known as “casing” are inserted into
the borehole and cemented in place. Casing is designed to support the borehole
walls against collapse, and provide an impervious barrier to prevent the unwanted
migration of fluids both into and out of the well. It is the main protection for groundwater from contamination.
Each diameter of casing is known as a “string” and multiple strings of casing are
typically run into a borehole, with each successive string being narrower so it can fit
inside all the others. Before drilling even starts, a large, corrugated pipe called the
conductor casing is often set upright a few meters deep in an excavation to hold
back unconsolidated soil, isolate very shallow and transient groundwater, and
2 What Is Fracking?
2.3 Hydraulic Fracturing Step by Step
Hydraulic fracturing is not a new technology. As mentioned earlier, it was invented
in 1947 and has been in use for more than 70 years. Fracking operations are carried
out by what the O&G industry calls “service companies.” These include Halliburton,
Schlumberger, Baker Hughes, CalFrac, FTS and others. Many of these companies
offer wellbore cementing, well logging, matrix stimulations, and other completion
services in addition to fracking.
Hydraulic fracturing operations are performed by highly trained, experienced
crews using specialized equipment. Like many other oilfield workers, frack crews
work around the clock, 7 days a week on “tours” that last until the job is completed.
Fracking is all they do, and they move themselves and their equipment from well
pad to well pad, often on tight schedules due to a shortage of crews or to avoid the
onset of bad weather.
The notion promulgated by some O&G opponents that the people who perform
fracking are careless, clueless, or irresponsible couldn’t be further from the truth.
Many of these folks are engineers holding at least Bachelor’s degrees, some are
licensed Professional Engineers (PE), and most have years of relevant experience.
The people who design, manage and monitor the actual hydraulic fracturing job on
site are all educated professionals. Hydraulic fracturing is an expensive and logistically complicated process, and there is plenty of competition for business. Frack
crews strive to complete the stimulation according to design specifications, maintain the fracture within the target zone, and use the minimum volumes of water, sand
and chemical additives necessary to create the desired frack. Mistakes do happen,
but companies who waste materials or frack into non-productive zones cost the
operating companies too much money and don’t last very long.
The logistics are formidable – all of the needed materials, sometimes including
the water have to be transported out to well locations, which are often in remote
areas. Everything needs to be inventoried and prepared for use, and then transported
to the next location after the hydraulic fracturing operation is completed. Many of
the fracking operations are done in “stages,” which means that multiple, individual
fracks take place at different zones within a single well. In the case of shale production where directional boreholes are used, there may be a half dozen or more wells
on a single pad, and all of them require staged fracks.
When wells are drilled, lengths of steel pipe known as “casing” are inserted into
the borehole and cemented in place. Casing is designed to support the borehole
walls against collapse, and provide an impervious barrier to prevent the unwanted
migration of fluids both into and out of the well. It is the main protection for groundwater from contamination.
Each diameter of casing is known as a “string” and multiple strings of casing are
typically run into a borehole, with each successive string being narrower so it can fit
inside all the others. Before drilling even starts, a large, corrugated pipe called the
conductor casing is often set upright a few meters deep in an excavation to hold
back unconsolidated soil, isolate very shallow and transient groundwater, and
2 What Is Fracking?