Geologists have known for years that substantial deposits of soil and natural gas are trap in the deep shale formation. The “shale reservoirs” create tens millions of years ago. In the world today, with modern horizontal drilling techniques and hydraulic fracturing, the oil and natural gas is trap in these shale reservoirs is being safely and efficiently produce, gather, and distribute to customers.
The process of completion and drilling:
Shale reservoirs are usually one mile or more below the surface, well below any underground source of drinking water which is typically no more than three hundred to one thousand feet below the surface. Additionally, steel pipes, called casing cement n place provide a multilayer barrier to protect the freshwater aquifers.
During the past 60 years, the oil and gas industry has conduct fracture activate in over a million wells worldwide. The initial steps are the same as for any conventional well. A hole is drill straight down using the freshwater base fluids, which cools the drill bit, carries the rock cuttings back to the surface, and stabilizes the wall of the wellbore.
Once the hole expands under the deepest freshwater level, the drill pipe detaches and replaces it with steel, called surface casing. And then cement gets pump down in the casing. When it reaches the bottom, it gets pump down and then back up between the casing and the borehole wall, creating a waterproof, extra safeguarding barricade between the wellbore and freshwater sources.
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Well Completion:
The first step in completing a well is the creation of a connection between the final casing and the reservoir rock. The lowering of the specializing tool is called a perforation gun. That equips with shape explosives charges to the rock layer containing oil or natural gas. This perforating gun gets fire, which creates holes through the casing cement, and into the target rock. This hole connects the reservoir and the wellbore.
Since these excavates are not very long and carry out more than a mile below ground, the whole process is unnoticeable on the surface. The gun removes the preparation of the next step which is hydraulic fracturing.
Hydraulic Fracturing:
The process consists of pumping the mixture of water and sand, also a few chemicals, under controlled conditions into deep underground reservoir formations. The chemicals are generally for lubrication, to keep bacteria from forming and which helps to carry the sand. These chemicals typically range in concentrations from 0.1 to 0.5 % by volume and help to improve the performance of the stimulation.
The activate fluid sent to trucks that force fluid into the wellbore and add through the perforations. This process creates fractures in the oil and gas reservoir rock. The sand in the fracture fluid remains in these fractures in the rock. Keep the pump open when the pressure is replace. This allows the previously trap oil or natural gas to flow to the wellbore more easily. This opening activate piece is then isolated with a specially plan plug. The performing guns are used to enter the next stage.
This stage is then hydraulically fracturing in the same manner. This process repeats along the entire horizontal section of the well, which extends several miles. Once it is complete the isolation plugs are drill out and the production begins. First, the water and then natural gas or oil flows into the horizontal casing and up the wellbore.
In the course of the initial production, approximately fifteen to fifty percent of the fracturing fluid gets to recover. This fluid gets recycle to use on the other fracturing operations. The whole process of growing a well common takes from three to five months.
