Hydraulic Fracturing: A chance to increase crude oil production
Fracking or Hydraulic fracturing is a method used in the oil industry in order to increase crude oil production in shale oil Wells with low permeability
Every reservoir has its own characteristic, none is similar to other. However, there are some rock characteristics which determine the extraction method that must be used.
Porosity and permeability are one of those aspects which are first evaluated in order to establish the reservoir profitability. There’s a relation between permeability and porosity, one cannot exist without the other, however this is not universal.
The first one refers to the amount of spaces (holes) in a rock, in which some fluid can be store. Meanwhile The second one refers to the connections between those spaces, which allows fluids to flow naturally.
Less permeable Rock formations such as bituminous shale, which are mostly found between four and sixteen thousand feet deep, make the extraction process more complicated. Due to its low permeability the fluids’ extraction process requires hydraulic fracturing.
What does it consist of?
This technique starts with vertical drilling of a well until it reaches the reservoir rock which contains gas and oil. Afterwards, some horizontal drillings are done in the shale in different directions.
Through this horizontal well the rock is fractured as a result of the high-pressure injection of water, sand and some chemical substances which forces the hydrocarbon’s outlet.
In some wells, drillers implement multistage fracking in order to create deep cracks. Short segments are drilled in the production casing; this allows to concentrate water burst in specific points.
Most of the time this process begins with Colied tubing work in order to eliminate Sulphur from the crude, organic material extraction and coating which cover each oil well.