Search results
Results from the WOW.Com Content Network
Environmental impact of fracking in the United States has been an issue of public concern, and includes the contamination of ground and surface water, methane emissions, [1] air pollution, migration of gases and fracking chemicals and radionuclides to the surface, the potential mishandling of solid waste, drill cuttings, increased seismicity and associated effects on human and ecosystem health.
Casing Diameters of a Borehole Casing Diagram premium gas tight connections on a casing string. Casing is a large diameter pipe that is assembled and inserted into a recently drilled section of a borehole. Similar to the bones of a spine protecting the spinal cord, casing is set inside the drilled borehole to protect and support the wellstream.
A well control company then will need to extinguish the well fire or cap the well, and replace the casing head and other surface equipment. If the flowing gas contains poisonous hydrogen sulfide , the oil operator might decide to ignite the stream to convert this to less hazardous substances.
Sometimes, the process of running in and cementing the casing is also included. After a well has been drilled, should the drilling fluids be removed, the well would eventually close in upon itself. Casing ensures that this will not happen while also protecting the wellstream from outside incumbents, like water or sand. [1] Perforated shoe
When the well has been drilled, it is completed to provide an interface with the reservoir rock and a tubular conduit for the well fluids. The surface pressure control is provided by a Christmas tree, which is installed on top of the wellhead, with isolation valves and choke equipment to control the flow of well fluids during production.
To determine the fracture gradient around the casing shoe and therefore establish the upper limit of the primary well control for the open hole section below the current casing. To investigate well bore capability to withstand pressure below the casing shoe in order to test the well engineering plan regarding the casing shoe setting depth.
When the water in the well is below the water table level, the pressure at the bottom of the well due to the water in the well will be less than P g and water will be forced into the well. Referring to the diagram, if z is the distance from the bottom of the well to the well water level and z T is the distance from the bottom of the well to the ...
In a completed well, there may be many annuli. The 'A' annulus is the void between the production tubing and the smallest casing string. The 'A' annulus can serve a number of crucial tasks, including gas lift and well kills. A normal well will also have a 'B' and frequently a 'C' annulus, between the different casing strings.