It wasn’t that long ago that oil and gas companies had to drill vertical wells to access energy-rich deposits of hydrocarbons. Some sites required multiple wells to be drilled to reach the hydrocarbons.
Today’s methods of hydraulic fracturing are different and more efficient than before, due to advancements in directional drilling and horizontal drilling technologies. Let’s explore the approaches we take to get the “good stuff” out today.
Modern-Day Advancements* Include:
- There’s more flexibility near the drill bit.
- Downhole steerable mud motors enable the well to be drilled in any direction if there’s enough distance to properly arc the drill string.
- The drilling angle can be adjusted so the drill string can be navigated through the shale.
- In-situ sensor technology mounted in the drill string means more operator control.
- Operators can avoid risky rock conditions and equipment-damaging shock, and monitor speed, pressure, and temperature in the drill bit.
- Equipment is designed to withstand the heat, pressure, vibration, and corrosion encountered during drilling.
*Other technology advancements are improving extraction yield, cost efficiency, and environmental impact.
Various Improvements Include:
- The chemistry of the proppant and additives to the fracturing fluids.
- The increased stimulation of a reservoir through precision microfracturing and fracture mapping.
- Well-completion technology that allows multiple segments of a drilled and fractured well to be accessed simultaneously.
Fracking Equipment (There’s a Lot of It)
One of the first steps to fracking is identifying the main access point. It has to have a significant amount of land nearby for all the equipment and traffic needed during the process. There also has to be space for piping the fuel.
Each step in the fracking process requires different components and equipment:
- A drill pipe assembly is used for most of the work to reach the shale bed. The drilling rig drives the assembly, which consists of a drill pipe with a drill bit mounted on the end. The drill pipe assembly not only grinds through layers of rock and soil, but also pumps drilling fluid into the hole to push fragments to the surface. The drill pipe can be up to several miles long at the final stages of drilling, and acts primarily as a conduit for the hydraulics and sensor reporting.
- Once the drill pipe gets to the right depth, flexible segments are mounted on the end of the drill string so it bends slightly to navigate toward the shale beds. The hydraulically powered mud motor allows the drill bit to rotate and change the angle of attack while the rest of the assembly remains fixed in place. The heavy-duty drill bit is made up of multiple cutting components — like carbide, fixed-cutter diamond, or diamond-filled materials — because the bit needs a lot of muscle to cut through the various layers of rock.
- Embedded within the drill pipe assembly are several MDW/LWD (measurement while drilling/logging while drilling) tools. These give continuous feedback of speed, location of the drill bit, vibration, temperature, resistance, roughness, and flow to the mud motor during operation. This data helps the drill operator to navigate the drill bit from the surface.
- After the hole has been drilled, the actual ‘fracking’ activity begins. The entire drilled well is surrounded in a concrete and steel casing to isolate the well from the surrounding soil. This is done for two reasons: to create a controlled path to bring the hydrocarbons to the surface, and to protect groundwater supplies.
- A perforation assembly then is fed down the wellbore. It consists of a feed tube with spaced rings mounted down the length of the tube. A locating device guides the tube down the hole to the same depth as the hydrocarbon deposits. The perforation assembly creates openings in the casing to release the hydrocarbon deposits. Perforating the casing is done with small, electrically detonated explosives; high-pressure abrasive fluid (water, sand and chemicals that maintain the openings) pumped through nozzles; or by other mechanical or electrical means. Several fractures are created in the casing and open into the shale bed.
- Once the fractures are created, the contents of the well (including any materials used in the fracking process) are pumped out. A positive pressure is held in the well to prevent the escape of any fracking fluids or hydrocarbons. Once complete, the pressure is released, the wellhead is installed, the well is considered completed, and the oil and gas flow can begin.
Now that you’re up-to-date with the Current Technologies and Equipment used to get the “good stuff” out, you should learn what the “good stuff” really is. Like how it’s affecting the environment, and you — which you can catch here. And then let us explain how modern technologies are working to answer some of your major concerns by Making the Process Safer.
Don’t forget to check back, or subscribe for an update! We’re wrapping up our Fracking Series with the controversial question: Why Frack (in the First Place)?