347AD. Oil wells are drilled in China up to 800 feet deep using bits attached to bamboo poles.
1264 Mining of seep oil in medieval Persia witnessed by Marco Polo on his travels through Baku.
1500s Seep oil collected in the Carpathian Mountains of Poland is used to light street lamps.
1594 Oil wells are hand dug at Baku, Persia up to 35 meters (115 feet) deep.
1735 Oil sands are mined and the oil extracted at Pechelbronn field in Alsace, France.
1792 Seep oil sold as Seneca oil sold after the indian tribe as a salve, mosquito repellent. Oil creek, Western Pennsylvania.
1802 A 58-ft brine well is drilled using a spring pole in the Kanawha Valley of West Virginia by the brothers David and Joseph Ruffner.
The well took 18 months to drill.
1815 Oil is produced in United States as an undesirable by-product from brine wells in Pennsylvania.
1848 First modern oil well is drilled in Asia, on the Aspheron Peninsula north-east of Baku, by Russian engineer F.N. Semyenov.
1849 Distillation of kerosene from oil by Dr. Abraham Gesner.
Kerosene finally replaced whale oil as the illuminant of choice and creates a new market for crude oil.
1850 Oil from hand-dug pits in California at Los Angeles is distilled to produce lamp oil by General Andreas Pico.
1854 First oil wells in Europe are drilled 30- to 50-meters deep at Bóbrka, Poland by Ignacy Lukasiewicz.
1854 Natural Gas from a water well in Stockton, California is used to light the Stockton courthouse.
1857 Michael Dietz invents a kerosene lamp that forces whale oil lamps off the market.
1858 First oil well in Ontario, Canada is drilled.
1859 First oil well in United States is drilled 69 feet deep at Titusville, Pennsylvania by Colonel Edwin Drake.
(Photo left by Hulton Archive/Getty Images) D'Arcy Exploration and the Burmah Oil Co on May 26th 1908 struck oil at Masjid-i-Suleiman oil in Persia (now Iran). The first big petroleum find in the Middle East,
Petroleum, in one form or another, has been used since ancient times, and is now important across society, including in economy, politics and technology. The rise in importance was mostly due to the invention of the internal combustion engine and the rise in commercial aviation
More than 4000 years ago, according to Herodotus and Diodorus Siculus, asphalt was used in the construction of the walls and towers of Babylon; there were oil pits near Ardericca (near Babylon), and a pitch spring on Zacynthus. Great quantities of it were found on the banks of the river
Today, about 90% of vehicular fuel needs are met by oil. Petroleum also makes up 40% of total energy consumption in the
The top three oil producing countries are Saudi Arabia, Russia, and the United States. About 80% of the world's readily accessible reserves are located in the Middle East, with 62.5% coming from the Arab 5: Saudi Arabia, UAE, Iraq, Qatar and Kuwait. A large portion of the world's total oil exists as unconventional sources, such as bitumen in Canada and Venezuela and oil shale. While significant volumes of oil are extracted from oil sands, particularly in Canada, logistical and technical hurdles remain, and Canada's oil sands are not expected to provide more than a few million barrels per day in the foreseeable future.
Left is of Sakhalin 1 Eastern Russia. Right is Urucu in the Brasilian Amazon dependent on the country and their idea of environmental sensitivity will depend on the size that drill site need to be. This was the first oil production operation to be awarded ISO14000
After the collapse of the OPEC-administered pricing system in 1985, and a short lived experiment with netback pricing, oil-exporting countries adopted a market-linked pricing mechanism. First adopted by PEMEX in 1986, market-linked pricing was widely accepted, and by 1988 became and still is the main method for pricing crude oil in international trade. The current reference, or pricing markers, are Brent, WTI, and Dubai/Oman.
The chemical structure of petroleum is heterogeneous, composed of hydrocarbon chains of different lengths. Because of this, petroleum may be taken to oil refineries and the hydrocarbon chemicals separated by distillation and treated by other chemical processes, to be used for a variety of purposes. See Petroleum products.
The most common distillations of petroleum are fuels. Fuels include:
Certain types of resultant hydrocarbons may be mixed with other non-hydrocarbons, to create other end products:
Reflection seismology, or 'seismic' as it is more commonly referred to by the oil industry, is used to map the subsurface structure of rock formations. Seismic technology is used by geologists and geophysicists who interpret the data to map structural traps that could potentially contain hydrocarbons. Seismic exploration is the primary method of exploring for hydrocarbon deposits, on land, under the sea and in the transition zone (the interface area between the sea and land). Although the technology of exploration activities has improved exponentially in the past 20 years, the basic principles for acquiring seismic data have remained the same.
In simple terms and for all of the exploration environments, the general principle is to send sound energy waves (using an energy source like dynamite or Vibroseis) into the Earth, where the different layers within the Earth's crust reflect back this energy. These reflected energy waves are recorded over a predetermined time period (called the record length) by using hydrophones in water and geophones on land. The reflected signals are output onto a storage medium, which is usually magnetic tape. The general principle is similar to recording voice data using a microphone onto a tape recorder for a set period of time. Once the data is recorded onto tape, it can then be processed using specialist software which will result in processed seismic profiles being produced. These profiles or data sets can then be interpreted for possible hydrocarbon reserves.
Right is a section of data known as a seismic survey report
Drilling preparation (http://science.howstuffworks.com)
The link above is a animation.
Once the site has been selected, it must be surveyed to determine its boundaries, and environmental impact studies may be done. Lease agreements, titles and right-of way accesses for the land must be obtained and evaluated legally. For off-shore sites, legal jurisdiction must be determined.
Once the legal issues have been settled, the crew goes about preparing the land:
Once the land has been prepared, several holes must be dug to make way for the rig and the main hole. A rectangular pit, called a cellar, is dug around the location of the actual drilling hole. The cellar provides a work space around the hole, for the workers and drilling accessories. The crew then begins drilling the main hole, often with a small drill truck rather than the main rig. The first part of the hole is larger and shallower than the main portion, and is lined with a large-diameter conductor pipe. Additional holes are dug off to the side to temporarily store equipment -- when these holes are finished, the rig equipment can be brought in and set up.
Depending upon the remoteness of the drill site and its access, equipment may be transported to the site by truck, helicopter or barge. Some rigs are built on ships or barges for work on inland water where there is no foundation to support a rig (as in marshes or lakes).
Rock coring bits
Are usually diamond encrusted bits designed to drill through the bedrock, with high speed rotation using water as a flushing agent, as well as coolong the bit, the drill produces a core sample which is then extracted from the estimated depth of the oil deposit as seen from the seismic survey. They are cut in half length ways and if you are lucky as in this case the dark patches are oil.
Photos courtesy Institute of Petroleum
This is a diagram of the mud circulating system.
Drilling mud, also known as drilling fluid, is a product which is used in the process of drilling deep boreholes. These holes may be drilled for oil and gas extraction, core, and a wide variety of other reasons. The mud can be an integral part of the drilling process, serving a number of functions.
One of the mostroles of drilling mud is as a . Drilling tremendous friction, which can damage the or the formation being drilled. Drilling mud cuts down on the friction, lowering the heat of drilling and reducing the of friction-related complications. The mud also acts as a carrier for the being drilled, with material becoming suspended in the mud and then being carried up the drill to the surface.
Using drilling mud protects theof a borehole by controlling variables such as friction and pressure. Different muds are needed for different circumstances, and the selection and formulation of mud is managed by a mud engineer. This engineer determines the correct viscosity level for the drilling mud, and adjusts factors such as of the mud as well. Water, , and -based muds can all be used, with ranging from true muds made with materials like to drilling fluid.
Drilling mud is recirculated throughout the drilling process. As it rises to the surface, it passes through screens which trap the materials from the borehole, before beingback into the system which delivers mud to the head of the drill bit. This recirculation process is designed to cut down on waste by reusing as much mud as possible. Depending on the materials being drilled, several screens may be needed to trap the materials, and sometimes the materials themselves are also coated in mud, which means that they will need to be even after .
http://www.youtube.com/watch?v=8FUumsr596g this link is to an excellent animation of the drilling process.
The Oil Drilling Process
Photo courtesy Phillips Petroleum Co.
Rotary workers trip drill pipe
The crew sets up the rig and starts the drilling operations. First, from the starter hole, they drill a surface hole down to a pre-set depth, which is somewhere above where they think the oil trap is located. There are five basic steps to drilling the surface hole:
Place the drill bit, collar and drill pipe in the hole.
Attach the kelly and turntable and begin drilling.
As drilling progresses, circulate mud through the pipe and out of the bit to float the rock cuttings out of the hole.
Add new sections (joints) of drill pipes as the hole gets deeper.
Remove (trip out) the drill pipe, collar and bit when the pre-set depth (anywhere from a few hundred to a couple-thousand feet) is reached.
Once they reach the pre-set depth, they must run and cement the casing -- place casing-pipe sections into the hole to prevent it from collapsing in on itself. The casing pipe has spacers around the outside to keep it centered in the hole.
The casing crew puts the casing pipe in the hole. The cement crew pumps cement down the casing pipe using a bottom plug, a cement slurry, a top plug and drill mud. The pressure from the drill mud causes the cement slurry to move through the casing and fill the space between the outside of the casing and the hole. Finally, the cement is allowed to harden and then tested for such properties as hardness, alignment and a proper seal.
Testing for Oil
Drilling continues in stages: They drill, then run and cement new casings, then drill again. When the rock cuttings from the mud reveal the oil sand from the reservoir rock, they may have reached the final depth. At this point, they remove the drilling apparatus from the hole and perform several tests to confirm this finding:
The diagram on the right shows the construction of a well looks like in cross section.
Horizontal and Directional drilling
Most horizontal wells begin at the surface as a vertical well. Drilling progresses until the drill bit is a few hundred feet above the target rock unit. At that point the pipe is pulled from the well and a hydraulic motor is attached between the drill bit and the drill pipe.
The hydraulic motor is powered by a flow of drilling mud down the drill pipe. It can rotate the drill bit without rotating the entire length of drill pipe between the bit and the surface. This allows the bit to drill a path that deviates from the orientation of the drill pipe.
After the motor is installed the bit and pipe are lowered back down the well and the bit drills a path that steers the well bore from vertical to horizontal over a distance of a few hundred feet. Once the well has been steered to the proper angle, straight-ahead drilling resumes and the well follows the target rock unit. Keeping the well in a thin rock unit requires careful navigation. Downhole instruments are used determine the azimuth and orientation of the drilling. This information is used to steer the drill bit.
Horizontal drilling is expensive. When combined with hydraulic fracturing a well can cost up to three times as much per foot as drilling a vertical well. The extra cost is usually recovered by increased production from the well. These methods can multiply the yield of natural gas or oil from a well. Many profitable wells would be failures without these methods.
Directional drilling can be used to reach targets that can not be drilled with a vertical well. For example: it may not be possible to get a drilling permit for a well located within a populated area or within a park. However, a well could be drilled just out side of the populated area or park and then steered directionally to hit the target.
One drilling pad can be used to drill a number of wells. This reduces the footprint of drilling operations. In 2010 the University of Texas at Arlington drilled 22 wells on a single platform. These wells are draining the natural gas from about 1100 acres beneath the campus. Over a 25-year life-time the wells are expected to produce a total of 110 billion cubic feet of natural gas. The alternative would be to drill many wells, each requiring a drilling pad, pond, access road and gathering line.
If a vertical well is drilled through a 50-foot-thick reservoir rock then natural gas or oil can seep into the well through 50 linear feet of "pay zone". However, if the well is turned to horizontal (or the same inclination as the rock unit) and drilled within that rock unit then the distance of penetration within the pay zone can be much greater. Some horizontal wells have over one mile of pay zone penetration.
If a well has a problem and begins to flow out-of-control, it must be sealed at depth or the pressure must be relieved. In this situation a "relief well" can be drilled from a nearby site. The relief well will be a directionally drilled well that intersects the bore of the problem well to drain off some of the pressure or to plug the well by pumping cement into the bore.
Blowouts and Fires
When drillers reach the final depth. These are actually dangerous conditions, and are (hopefully) prevented by the blowout preventer and the pressure of the drilling mud.
In most wells, the oil flow must be started by acidizing or fracturing the well.
Once they have reached the final depth, the crew completes the well to allow oil to flow into the casing in a controlled manner. First, they lower a perforating gun into the well to the production depth. The gun has explosive charges to create holes in the casing through which oil can flow. After the casing has been perforated, they run a small-diameter pipe (tubing) into the hole as a conduit for oil and gas to flow up the well. A device called a packer is run down the outside of the tubing. When the packer is set at the production level, it is expanded to form a seal around the outside of the tubing. Finally, they connect a multi-valved structure called a Christmas tree to the top of the tubing and cement it to the top of the casing. The Christmas tree allows them to control the flow of oil from the well.
Once the well is completed, they must start the flow of oil into the well. For limestone reservoir rock, acid is pumped down the well and out the perforations. The acid dissolves channels in the limestone that lead oil into the well. For sandstone reservoir rock, a specially blended fluid containing proppants (sand, walnut shells, aluminum pellets) is pumped down the well and out the perforations.
The pressure from this fluid makes small fractures in the sandstone that allow oil to flow into the well, while the proppants hold these fractures open. Once the oil is flowing, the oil rig is removed from the site and production equipment is set up to extract the oil from the well.
When oilfields start to reduce their production a system known as water injection is used in an attempt to push the remaining oil towards the production wells. This diagram shows how it is done.
Photo Oklahoma 1981 http://www.sjvgeology.org/history/gushers_world.html
This text from http://en.wikipedia.org/wiki/Pumpjack (Drawing Mark Francis)
In the early days, pumpjacks were actuated by rod lines running horizontally above the ground to an eccentric wheel in a mechanism known as a Central Power. The Central Power, which might operate a dozen or more pumpjacks, was powered by a steam or internal combustion engine or by an electric motor. Among the difficulties with this scheme was maintaining system balance as individual well loads changed.
Modern pumpjacks are powered by a prime mover. This is commonly an electric motor, but internal combustion engines are used in isolated locations without access to electricity. Common off-grid pumpjack engines run on casing gas produced from the well, but pumpjacks have been run on many types of fuel, such as propane and diesel. In harsh climates such motors and engines may be housed in a building for protection from the elements.
The prime mover of the pumpjack runs a set of pulleys to the transmission which drives a pair of cranks, generally with counterweights on them to assist the motor in lifting the heavy string of rods. The cranks raise and lower one end of an walking or I-beam which is free to move on an A-frame. On the other end of the beam, there is a curved metal box called a Horse Head or Donkeys Head, so named due to its appearance. A cable usually made of steel called a bridle, connects the horse head to the polished rod, a piston that passes through the stuffing box.
The polished rod has a close fit to the stuffing box, letting it move in and out of the tubing without fluid escaping. (The tubing is a pipe that runs to the bottom of the well through which the liquid is produced.) The bridle follows the curve of the horse head as it lowers and raises to create a nearly vertical stroke. The polished rod is connected to a long string of rods called sucker rods, which run through the tubing to the down-hole pump, usually positioned near the bottom of the well.
At the bottom of the tubing is the down-hole pump. This pump has two ball check valves: a stationary valve at bottom called the standing valve, and a valve on the piston connected to the bottom of the sucker rods that travels up and down as the rods reciprocate, known as the traveling valve. Reservoir fluid enters from the formation into the bottom of the borehole through perforations that have been made through the casing and cement (the casing is a larger metal pipe that runs the length of the well, which has cement placed between it and the earth; the tubing, pump and sucker rods are all inside the casing).
When the rods at the pump end are traveling up, the traveling valve is closed and the standing valve is open (due to the drop in pressure in the pump barrel). Consequently, the pump barrel fills with the fluid from the formation as the traveling piston lifts the previous contents of the barrel upwards. When the rods begin pushing down, the traveling valve opens and the standing valve closes (due to an increase in pressure in the pump barrel). The traveling valve drops through the fluid in the barrel (which had been sucked in during the upstroke). The piston then reaches the end of its stroke and begins its path upwards again, repeating the process.
Often, gas is produced through the same perforations as the oil. This can be problematic if gas enters the pump, because it can result in what is known as gas locking, where insufficient pressure builds up in the pump barrel to open the valves (due to compression of the gas) and little or nothing is pumped. To preclude this, the inlet for the pump can be placed below the perforations. As the gas-laden fluid enters the well bore through the perforations, the gas bubbles up the annulus (the space between the casing and the tubing) while the liquid moves down to the standing valve inlet. Once at the surface, the gas is collected through piping connected to the annulus.
Decline in production
After initial discover and production, typical oil reservoirs lose the drive mechanism of gas or water that originally forced the oil to the surface. Many oil fields produce only 12-15% of the original oil in place. With secondary recovery methods using gas or water injection, another 15-20% of the original oil may be produced.
Heavy oil is more difficult to produce and often does not reach even the 12-15% initial production levels typical of light weight oil. In many cases, 85-90% of the original oil is still in the ground, awaiting production.
In order to keep production figures up water may be injected into the reservoir to keep the pressure up and to push oil towards producing wells. This operation has be used since the 1930's.
In many cases 4 barrels of water will be produced for every one barrel of oil and so with a good water management system this water can be reintroduced into the reservoir.
In these CO2 conscious times.
Oil fields are defined as an ensemble of geological reservoirs in the same region, which have been holding oil and/or gas for millions of years. The CO2 storage capacity in oil fields is estimated to be around 1000 Gt (billions of tons) (Source: IEA). CO2 injection in oil fields may result in an increased production of hydrocarbons, through a technique known as EOR (Enhanced Oil Recovery). Depending on the pressure and temperature of the reservoir, the injected CO2 will dissolve into the oil, reducing the interfacial tension and viscosity which will augment its mobility in the reservoir. This may increase the production up to 40% of the residual oil volume, which could not be recovered by conventional techniques. This technology, already employed in the U.S. since the 60's, has also been implanted in Brazil by PETROBRAS in Bahia since 1987.