Hydraulic fracturing or fracking is one of the controversial topics that are arising in the recent period. The truth is fracking is beneficial to the economy but not to the environment. Fracking helps to improve the productivity of oil and gases, but at the same time, the toxified fracturing liquid contains harmful radioactive components that can’t be disposed or filtered. This is why the public goes against hydraulic fracturing and protests arises.
With the hydraulic fracturing process, the unexposed oils and gases that are trapped inside the shale formation can be extracted easily. Up to a specific point, the fracking process is similar to that of the drilling approach. Fracking is more productive than the drilling process because in fracking it cracks the hard-to-reach shale rocks and extracts the trapped oil and gases from it. We can discuss more on how fracking is done in this section.
Also Read: Why Is Fracking Controversial?
Procedure for Hydraulic Fracking
Hydraulic fracturing is a complicated and dangerous process that takes months to complete. The fracking site can be any location, it can be a desert, rural villages, forest, or urban cities. The only fracking requirement is that the site needs plenty of mineral deposits and acres of land availability for fracking. The following are the steps of the hydraulic fracking procedure.
- Site Preparation: After completing continuous researches, the site with large quantities of minerals will be identified. The next stage is to locate the landowner and taking permission from the concerned department. The well-pad size will range between 4-2 acres depending on the fracking operation performing. After the initial researches and studies a proper road transportation facility for heavy-duty equipment like cranes, tankers, excavators, etc… need to be arranged. Also, all existing infrastructures and vegetations need to be cleared and levelled before the fracking procedure begins.
- Components Arrangements: The most important component for hydraulic fracking is water. Almost 90% of the fracking fluid contains water and the quantity will be tens of thousands of galloons. This water is collected either from the groundwater source or by recycling the previous fracking wastewater. The remaining components like pipings, cement, sand, clay, acids, slickwater, detergents and all other chemicals are assembled. Also, machinery and equipment like the slurry blender, pumps, monitoring equipment, storage tanks, hoses, meters & gauges, etc… are also transported to the site.
- Drill Rig Installation: Drill rigs are used for drilling wells on the earth subsurface for exploring minerals and water. There are different categories of drill rigs that include mobile rigs(installed on trucks, excavators,etc… or that can be disassembled to carry from one location to other) and permanent rigs (fixed large rigs). A drill rig is selected based on the requirements and is assembled at the fracking site.
- Drilling & Casing: After installing the rig, the horizontal well drilling process begins. Horizontal drilling is done to a depth of 2500-3000 meters in a maximum of 12cm diameter from the earth surface. The point where horizontal drilling has completed is called “kick-off-point”. After completing this drilling, the hole is cased with steel pipes and cemented to avoid the contamination of surface water. From the kick-off-point, the drilling tool turns left or right in a 90° angle and drills horizontally through the shale rock up to 1.5 Km and steel casing is provided for this drilled hole. An explosive loaded perforating gun with charged explosives will puncture tiny holes(like kitchen colander) on the steel casing horizontally placed through the shale rock layer.
After completing the above-mentioned procedure, the hydraulic fracturing process will begin with a small delay of 3-4 months. After this, the actual fracking will begin.
- Hydraulic Fracturing: The fracking fluid containing 90% of water, 9.5% of sand and other proppants, and 0.5% of chemical additives(acids, carbonates, polyacrylamide, glutaraldehyde, ethylene glycol, and more) is used for the fracking process. The slurry mixture machine will mix these water, sand, acids(acetic acid, hydrochloric acid, citric acid, etc.), gels(aluminium phosphate-ester oil gels, conventional linear gels, borate-crosslinked fluids, etc.), foams, and compressed gases together to form fracking fluid. The high pressure and high volume pumps will pump these fluids into the drilled well. The high-pressure fracking fluid will pass through the steel casing and cracks the shale rocks by flowing out through the punched holes. The sand and clay will enter into the fissure and let it open for the gas molecules to escape from the shale rocks to the fracking fluid in well.
- Flowback Stage & Wastewater Disposal: The gas molecules will come to the top of the fracking fluid. This fluid is collected for processing and then delivered to the consumers through the pipelines after purification and compression. The toxic wastewater resulting from fracking is temporarily stored in onsite retention ponds and tanks. From, there it is transferred to a wastewater treatment plant or disposed to protected wellbores that prevent contamination of groundwater.
Also Read: Hydraulic System Advantages and Disadvantages