A borehole is the generalised term for any narrow shaft drilled in the ground, either vertically or horizontally. Shaft mining or Shaft sinking refers to the method of excavating a vertical or near-vertical tunnel from the top down where there is initially no access to the bottom A borehole may be constructed for many different purposes including the extraction of water or fluid (such as oil) or gases (such as natural gas or methane), as part of a geotechnical investigation or environmental site assessment, for mineral exploration, or as a pilot hole for installing piers or underground utilities. Petroleum ( L petroleum, from Greek πετρέλαιον, lit Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Geotechnical investigations are performed by geotechnical engineers or engineering geologists to obtain information on the physical properties of soil and rock around a site to design A Phase I Environmental Site Assessment is a report prepared for a real estate holding which identifies potential or existing environmental contamination liabilities. Boreholes used as water wells are described in more depth in that article.
In the engineering and environmental consulting fields, the term is used to collectively describe all of the various types of holes drilled as part of a geotechnical investigation or environmental site assessment (a so-called Phase II ESA). Engineering is the Discipline and Profession of applying technical and scientific Knowledge and Environmental consulting is often a form of compliance Consulting, in which the consultant ensures that the client maintains an appropriate measure of compliance with Geotechnical investigations are performed by geotechnical engineers or engineering geologists to obtain information on the physical properties of soil and rock around a site to design This includes holes advanced to collect soil samples, water samples or rock cores, to advance in situ sampling equipment, or to install monitoring wells or piezometers. In situ (ɪn siːˈtuː is a Latin phrase meaning in the place. A piezometer is a small diameter Water well used to measure the Hydraulic head of Groundwater in Aquifers Similarly it may also be a standpipe Samples collected from boreholes are often tested in a laboratory to determine their physical properties, or to assess levels of various chemical constituents or contaminants.
Typically, a borehole used as a well is completed by installing a vertical pipe (casing) and well screen to keep the borehole from caving. This also helps prevent surface contaminants from entering the borehole and protects any installed pump from drawing in sand and sediment. Pollution is the introduction of contaminants into an environment that causes instability disorder harm or discomfort to the physical systems or living organisms they are in When completed in this manner the borehole is then more commonly called a well: whether it is a water well, oil well or natural gas extraction well. West Texas PumpjackJPG|thumb|right|300px|This Pumpjack located south of Midland TX is a common sight in West Texas.
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Installation
Boreholes may be drilled using a drilling rig, or by a hand-operated rig. For a detailed diagram of a Petroleum drilling rig, See Drilling rig (petroleum A drilling rig is a machine which creates holes (usually called The machinery and technique to advance a borehole varies considerably according to manufacturer, geological conditions, fluid to be extracted, and job specification.
Climate proxy
Borehole temperatures can be used as temperature proxies. In Climate research a proxy variable is something that is probably not in itself of any great interest but from which a variable of interest can be obtained This is because heat transfer through ground is slow, so that by measuring temperature (and using the proper mathematical formulas) past temperatures can be inferred several hundred years prior (Huang et al. 2000).
See also
References
- Huang, S. In Machining, boring is the process of enlarging a hole that has already been drilled (or cast by means of a single-point cutting tool (or of a boring For a detailed diagram of a Petroleum drilling rig, See Drilling rig (petroleum A drilling rig is a machine which creates holes (usually called P. , Pollack, H. N. , Shen, P. Y. Temperature trends ever the past five centuries reconstructed from borehole temperatures. Nature, 403, 6771, pp 756-758, 2000. doi:10. 1038/35001556.
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