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Baptist well drilling is a very simple, manual method to drill water wells. The Baptist drilling rig can be built in any ordinary arc welding workshop and materials for a basic version costs about 150 US dollars (2006 prices). In suitable conditions, boreholes over 100 m deep have been drilled with this method.
The method was developed by Terry Waller, a North American Baptist missionary in Africa and Bolivia. It applies some of the same principles used in mechanized commercial well drilling, but does so using the simplest, most available and cheapest possible materials.
Rural people in developing countries often cannot afford to have specialists drill or dig wells for them. This method was developed to provide poor people with a way to help themselves with their water supply.
A Baptist drilling rig, fit to drill holes up to 30 metres (98 ft) deep, can be built in Nicaragua for about US $150. This includes all essential non-common tools to operate it. Its core element, the drill bits, can be made in about any arc-welding workshop, using only scrap steel and materials that can be found in virtually any hardware store.
Once the well is drilled, it is cased with an inexpensive PVC tube. Fitting the well with a slab of concrete as a sanitary seal and a simple PVC piston pump (also built by the users themselves) will cost about 2.5 dollars per meter well depth.
A hybrid between sludging and percussion drilling, this method permits to drill through all kinds of loose alluvial soils, sands, silts and clays, as well as “soft” rocks, like light conglomerates, consolidated volcanic ashes, some calcareous rocks and weathered materials. It will not penetrate hard igneous rock or boulders (e.g. in ancient river beds).
Like in sludging, the drilling process is continuous: the drill bit is normally not removed from the borehole until it is finished and the broken-up material is pumped to the surface in the drilling liquid (mud). But instead of using a hand as a valve on top of the drill pipe (sludging), the drill bit itself doubles as a foot-valve. The operator’s hand does not have to reach the end of the drill pipe and drill stem extensions can be several meters long.
Percussion action is performed by lifting the drill stem with a rope over a pulley, attached to a simple derrick, made with locally available materials, such as wood or bamboo poles.
The borehole diameter is kept as small as possible in order to remove a minimum of material and hence advance rapidly. The standard drill bit is based on 1.25 inches (3.2 cm) water pipe fittings and unless a larger diameter is required, the borehole is cased with 1.5 inches (3.8 cm) PVC pipe.
The main drill tool consists of a length of metal pipe with a bit/valve. Extensions are standard PVC potable water pipes.
No temporary casing is used. The borehole being kept full of mud and the “caking” of mud into any unstable sand layers, as a consequence of the percussion action and friction of the smooth lateral edges of the bit, is normally sufficient to stabilize it. The drilling mud is evacuated from the borehole after casing the well by pouring or injecting water into the casing, called backwashing.
This technique adapts best to sand, loam and light rock. The standard drill bits also work through sticky and even consolidated clays. Nevertheless, best results in varying conditions are obtained with an array of different bits:
If required, the upper part of the well can be reamed and cased with larger diameter pipe (3 or 5 inches), to accommodate larger pumps. A shallow (large diameter) rope pump, for example, may require a wider well and submersible pumps commonly need at least 4". Note that there is no need to enlarge the entire depth of the borehole: reaming until slightly below the lowest expected water table (the pump's water intake) is sufficient.
An oil well is a drillhole boring in Earth that is designed to bring petroleum oil hydrocarbons to the surface. Usually some natural gas is released as associated petroleum gas along with the oil. A well that is designed to produce only gas may be termed a gas well. Wells are created by drilling down into an oil or gas reserve that is then mounted with an extraction device such as a pumpjack which allows extraction from the reserve. Creating the wells can be an expensive process, costing at least hundreds of thousands of dollars, and costing much more when in hard to reach areas, e.g., when creating offshore oil platforms. The process of modern drilling for wells first started in the 19th century, but was made more efficient with advances to oil drilling rigs during the 20th century.
In petroleum exploration and development, formation evaluation is used to determine the ability of a borehole to produce petroleum. Essentially, it is the process of "recognizing a commercial well when you drill one".
A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water, other liquids, or gases. It may also be part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage.
In the oil and gas industry, the term wireline usually refers to the use of multi-conductor, single conductor or slickline cable, or "wireline", as a conveyance for the acquisition of subsurface petrophysical and geophysical data and the delivery of well construction services such as pipe recovery, perforating, plug setting and well cleaning and fishing. The subsurface geophysical and petrophysical information results in the description and analysis of subsurface geology, reservoir properties and production characteristics.
Well logging, also known as borehole logging is the practice of making a detailed record of the geologic formations penetrated by a borehole. The log may be based either on visual inspection of samples brought to the surface or on physical measurements made by instruments lowered into the hole. Some types of geophysical well logs can be done during any phase of a well's history: drilling, completing, producing, or abandoning. Well logging is performed in boreholes drilled for the oil and gas, groundwater, mineral and geothermal exploration, as well as part of environmental and geotechnical studies.
Well control is the technique used in oil and gas operations such as drilling, well workover and well completion for maintaining the hydrostatic pressure and formation pressure to prevent the influx of formation fluids into the wellbore. This technique involves the estimation of formation fluid pressures, the strength of the subsurface formations and the use of casing and mud density to offset those pressures in a predictable fashion. Understanding pressure and pressure relationships is important in well control.
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. The lower portion is typically held in place with cement. Deeper strings usually are not cemented all the way to the surface, so the weight of the pipe must be partially supported by a casing hanger in the wellhead.
In geotechnical engineering, drilling fluid, also known as drilling mud, is used to aid the drilling of boreholes into the earth. Used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells.
A tube well is a type of water well in which a long, 100–200 millimetres (3.9–7.9 in)-wide, stainless steel tube or pipe is bored underground. The lower end is fitted with a strainer, and a pump lifts water for irrigation. The required depth of the well depends on the depth of the water table.
A drill stem test (DST) is a procedure for isolating and testing the pressure, permeability and productive capacity of a geological formation during the drilling of a well. The test is an important measurement of pressure behaviour at the drill stem and is a valuable way of obtaining information on the formation fluid and establishing whether a well has found a commercial hydrocarbon reservoir.
In drilling technology, casing string is a long section of connected oilfield pipe that is lowered into a wellbore and cemented. The purpose of the casing pipe is as follows:
Directional boring, also referred to as horizontal directional drilling (HDD), is a minimal impact trenchless method of installing underground utilities such as pipe, conduit, or cables in a relatively shallow arc or radius along a prescribed underground path using a surface-launched drilling rig. Directional boring offers significant environmental advantages over traditional cut and cover pipeline/utility installations. The technique is routinely used when conventional trenching or excavating is not practical or when minimal surface disturbance is required.
A deep foundation is a type of foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. A pile or piling is a vertical structural element of a deep foundation, driven or drilled deep into the ground at the building site.
A well is an excavation or structure created in the ground by digging, driving, or drilling to access liquid resources, usually water. The oldest and most common kind of well is a water well, to access groundwater in underground aquifers. The well water is drawn up by a pump, or using containers, such as buckets or large water bags that are raised mechanically or by hand. Water can also be injected back into the aquifer through the well. Wells were first constructed at least eight thousand years ago and historically vary in construction from a simple scoop in the sediment of a dry watercourse to the qanats of Iran, and the stepwells and sakiehs of India. Placing a lining in the well shaft helps create stability, and linings of wood or wickerwork date back at least as far as the Iron Age.
Sludging is a very simple well drilling method developed in ancient India but still used extensively in developing countries, where capital is scarce, but manpower abundant.
Oilfield terminology refers to the jargon used by those working in fields within and related to the upstream segment of the petroleum industry. It includes words and phrases describing professions, equipment, and procedures specific to the industry. It may also include slang terms used by oilfield workers to describe the same.
The India Mark II is a human-powered pump designed to lift water from a depth of 50–80 m. The Mark II is world's most widely used water handpump. The pump was designed in the 1970s to serve village water needs in developing countries and rural areas. The pump is installed on top of a drilled well or borehole and lifts water from the bottom of the well through repeatedly moving the pump handle up and down. Several manufacturers, primarily in India, manufacture the pump which now falls under public domain. By the mid-1990s, five million of the pumps had been manufactured and installed. India Mark ll Pumps' bored hole may be fitted with solar thermal siphon pump to run on solar energy. The resulting assembly may be called the India Mark IV Solar Pump.
Multilevel Groundwater Monitoring Systems, also referred to as Multi-Depth Groundwater Monitoring Systems, Multilevel Systems (MLSs), or Engineered Nested Wells, are engineered technologies installed in single boreholes above and/or below the water table to obtain data from different depth intervals. The technologies may consist of various pipes, liners, access ports, sampling pumps, pressure sensors, and sealing mechanisms that are installed temporarily or permanently in boreholes drilled into unconsolidated sediments or bedrock.
Ice drilling allows scientists studying glaciers and ice sheets to gain access to what is beneath the ice, to take measurements along the interior of the ice, and to retrieve samples. Instruments can be placed in the drilled holes to record temperature, pressure, speed, direction of movement, and for other scientific research, such as neutrino detection.