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101-571: In 2007, the U.S. Department of Energy ranked The Spraberry Trend third in the United States by total proved reserves, and seventh in total production. Estimated reserves for the entire Spraberry-Dean unit exceeded 10 billion barrels (1.6 × 10 m), and by the end of 1994, the field had reported a total production of 924 million barrels (146,900,000 m). The Spraberry Trend covers a large area – around 2,500 square miles (6,500 km) – and includes portions of two Texas geographical regions,

202-554: A catalyst for breaking down the gel. Sometimes pH modifiers are used to break down the crosslink at the end of a hydraulic fracturing job, since many require a pH buffer system to stay viscous. At the end of the job, the well is commonly flushed with water under pressure (sometimes blended with a friction reducing chemical.) Some (but not all) injected fluid is recovered. This fluid is managed by several methods, including underground injection control, treatment, discharge, recycling, and temporary storage in pits or containers. New technology

303-514: A convention in Midland of hundreds of engineers and petroleum geologists reached no consensus on the issues with the field, although the peculiar and irregularly fractured nature of the oil-bearing rocks seemed to be a large part of the problem. In May 1952, there were more than 1,630 Spraberry wells in the Midland basin, most recently drilled, but local enthusiasm had ended. In the following years, each operator developed its own methods of dealing with

404-611: A fort, but does not present the original Spanish. In Beyond the Mississippi (1867), Albert D. Richardson , who traversed the region from east to west in October 1859, wrote that "the ancient Mexicans marked a route with stakes over this vast desert, and hence its name." Other sources refer to "stakes" used to mark routes on the featureless plain, often meaning piles of stone, bone, and cow dung . According to Place Names of New Mexico , others have speculated that "stakes" refers to

505-418: A frenzy of drilling in the region surrounding Midland. Unfortunately for most of the speculators, investors, and outside independent oil companies, most of the newly drilled wells behaved badly; they produced oil nicely for a short time, and then production fell off sharply, with wells often failing to break even. In 1950, the cost of drilling and putting down 8,000 feet (2,400 m) of steel casing required

606-554: A group of Hollywood models, and had these women photographed on the drilling rigs, working the equipment in the nude. Using the normal 40-acre (160,000 m) spacing employed elsewhere in West Texas proved impossible on the Spraberry; wells that close competed against each other, as yields per-acre from the difficult reservoir were dropping into the hundreds of barrels rather than the expected thousands. Oil companies resorted to

707-702: A low-permeability zone that sometimes forms at the rock-borehole interface. In such cases the fracturing may extend only a few feet from the borehole. In the Soviet Union , the first hydraulic proppant fracturing was carried out in 1952. Other countries in Europe and Northern Africa subsequently employed hydraulic fracturing techniques including Norway, Poland, Czechoslovakia (before 1989), Yugoslavia (before 1991), Hungary, Austria, France, Italy, Bulgaria, Romania, Turkey, Tunisia, and Algeria. Massive hydraulic fracturing (also known as high-volume hydraulic fracturing)

808-453: A monitoring unit. Associated equipment includes fracturing tanks, one or more units for storage and handling of proppant, high-pressure treating iron , a chemical additive unit (used to accurately monitor chemical addition), fracking hose (low-pressure flexible hoses), and many gauges and meters for flow rate, fluid density, and treating pressure. Chemical additives are typically 0.5% of the total fluid volume. Fracturing equipment operates over

909-740: A patent for an " exploding torpedo ". It was employed in Pennsylvania , New York , Kentucky , and West Virginia using liquid and also, later, solidified nitroglycerin . Later still the same method was applied to water and gas wells. Stimulation of wells with acid, instead of explosive fluids, was introduced in the 1930s. Due to acid etching , fractures would not close completely resulting in further productivity increase. Harold Hamm , Aubrey McClendon , Tom Ward and George P. Mitchell are each considered to have pioneered hydraulic fracturing innovations toward practical applications. The relationship between well performance and treatment pressures

1010-431: A period in the 1950s the abundant natural gas in the reservoir was simply flared off – burned above the wellhead – since no recovery infrastructure existed. Steel was expensive, transport costs high, and profit margins from the field were too low to allow the development of the sort of gas pipelines that exist in most modern oil fields. Aircraft pilots reported that hundreds of square miles of west Texas were lit at night from

1111-564: A propped fracture. Injection of radioactive tracers along with the fracturing fluid is sometimes used to determine the injection profile and location of created fractures. Radiotracers are selected to have the readily detectable radiation, appropriate chemical properties, and a half life and toxicity level that will minimize initial and residual contamination. Radioactive isotopes chemically bonded to glass (sand) and/or resin beads may also be injected to track fractures. For example, plastic pellets coated with 10 GBq of Ag-110mm may be added to

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1212-528: A range of pressures and injection rates, and can reach up to 100 megapascals (15,000 psi) and 265 litres per second (9.4 cu ft/s; 133 US bbl/min). A distinction can be made between conventional, low-volume hydraulic fracturing, used to stimulate high-permeability reservoirs for a single well, and unconventional, high-volume hydraulic fracturing, used in the completion of tight gas and shale gas wells. High-volume hydraulic fracturing usually requires higher pressures than low-volume fracturing;

1313-408: A set number of days per month during which they could pump oil and flare gas. The overall gas reserves of the field were estimated to be over two trillion cubic feet; during the peak of the early 1950s gas-flaring, over 220 million cubic feet (6,200,000 m) per day were burned. The field grew in the 1960s with the annexation of several adjacent oil pools, and overall production increased with

1414-567: A single enormous sedimentary unit known as the Spraberry Sand, which consists of complexly mixed fine sandstone and calcareous or silicate mudstone and siltstone , deposited in a deep water environment distinguished by channel systems and their associated submarine fans, all of Permian age. The sands are interbedded with shales , and typically pinch-out updip. Oil accumulated in stratigraphic traps as it migrated upward from source rocks until encountering impermeable barriers, either in

1515-525: A treeless, desolate waste of uninhabitable solitude, which always has been, and must continue uninhabited forever. During the 1854 Marcy-Neighbors expedition, Dr. George Getz Shumard noted, "Beyond the mountain appeared a line of high bluffs (the Llano Estacado) which in the distance looked like clouds floating upon the horizon." Herman Lehmann was captured by the Apache in 1870 and described

1616-407: A well to produce 50,000 barrels (7,900 m) just to break even in the face of the low federally mandated price of $ 2.58/barrel. Local companies that had been skeptical of the Spraberry since the beginning of the boom did not suffer the losses of the outsiders who had come in expecting to profit in the huge oil play. Even the professional geologists could not agree on what was wrong: in October, 1951,

1717-530: Is a technique first applied by Pan American Petroleum in Stephens County, Oklahoma , US in 1968. The definition of massive hydraulic fracturing varies, but generally refers to treatments injecting over 150 short tons, or approximately 300,000 pounds (136 metric tonnes), of proppant. American geologists gradually became aware that there were huge volumes of gas-saturated sandstones with permeability too low (generally less than 0.1 millidarcy ) to recover

1818-566: Is a wedge of sediments built up eastward of the Rocky Mountains as they were uplifted in the Miocene , with the consequent alluvial fans referred to as the "Gangplank". The Ogallala Aquifer is the main freshwater source for the region and consists of braided stream deposits filling in valleys during humid climatic conditions, followed by a sub-humid to arid climate and thick eolian (wind-blown) sand and silt. Caliche layers cap

1919-511: Is at an average depth of 6,800 feet (2,100 m) across the entire region, which is about 150 miles (240 km) long by 70 wide. The first well drilled into the formation was by Seaboard Oil Company in 1943, on land owned by farmer Abner Spraberry in Dawson County. While the well bore showed an oil-bearing unit had been found, and hence received Spraberry's name, it did not produce commercial quantities of oil. That changed in 1949, when

2020-426: Is called waterless fracturing . When propane is used it is turned into vapor by the high pressure and high temperature. The propane vapor and natural gas both return to the surface and can be collected, making it easier to reuse and/or resale. None of the chemicals used will return to the surface. Only the propane used will return from what was used in the process. The proppant is a granular material that prevents

2121-466: Is continually developing to better handle waste water and improve re-usability. Measurements of the pressure and rate during the growth of a hydraulic fracture, with knowledge of fluid properties and proppant being injected into the well, provides the most common and simplest method of monitoring a hydraulic fracture treatment. This data along with knowledge of the underground geology can be used to model information such as length, width and conductivity of

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2222-587: Is deeply entrenched in Texas mythology, but the real interpretation of Llano Estacado is sensible geologic: it means 'stockaded' or 'palisaded' plains - which is precisely how the edge of the plains appear when viewed from below the caprock . The Llano Estacado lies at the southern end of the Western High Plains ecoregion of the Great Plains of North America; it is part of what was once called

2323-537: Is dotted by numerous small playa lakes , depressions that seasonally fill with water and provide habitat for waterfowl . The Llano Estacado has a cold semiarid climate ( Köppen BSk ), characterized by long, hot summers and cold winters. Rainfall is relatively low; the entire region receives fewer than 23 in (580 mm) of rainfall annually, and the western part receives as little as 14 in (360 mm). High summer temperatures (average high July temperature above 90 °F or 32 °C) mean that most of

2424-488: Is generally necessary to achieve adequate flow rates in shale gas , tight gas , tight oil , and coal seam gas wells. Some hydraulic fractures can form naturally in certain veins or dikes . Drilling and hydraulic fracturing have made the United States a major crude oil exporter as of 2019, but leakage of methane , a potent greenhouse gas , has dramatically increased. Increased oil and gas production from

2525-414: Is improved by sensors placed in multiple azimuths from the monitored borehole. In a downhole array location, accuracy of events is improved by being close to the monitored borehole (high signal-to-noise ratio). Monitoring of microseismic events induced by reservoir stimulation has become a key aspect in evaluation of hydraulic fractures, and their optimization. The main goal of hydraulic fracture monitoring

2626-498: Is often interpreted as meaning "Staked Plains", although " stockaded " or " palisaded plains" have also been proposed, in which case the name would derive from the steep escarpments on the eastern, northern, and western periphery of the plains. Leatherwood writes that Francisco Coronado and other European explorers described the Mescalero Ridge on the western boundary as resembling "palisades, ramparts, or stockades" of

2727-410: Is particularly significant in "tensile" ( Mode 1 ) fractures which require the walls of the fracture to move against this pressure. Fracturing occurs when effective stress is overcome by the pressure of fluids within the rock. The minimum principal stress becomes tensile and exceeds the tensile strength of the material. Fractures formed in this way are generally oriented in a plane perpendicular to

2828-511: Is particularly useful in shale formations which do not have sufficient permeability to produce economically with a vertical well. Such wells, when drilled onshore, are now usually hydraulically fractured in a number of stages, especially in North America. The type of wellbore completion is used to determine how many times a formation is fractured, and at what locations along the horizontal section. In North America, shale reservoirs such as

2929-502: Is permeable enough to allow the flow of gas, oil, salt water and hydraulic fracturing fluids to the well. During the process, fracturing fluid leakoff (loss of fracturing fluid from the fracture channel into the surrounding permeable rock) occurs. If not controlled, it can exceed 70% of the injected volume. This may result in formation matrix damage, adverse formation fluid interaction, and altered fracture geometry, thereby decreasing efficiency. The location of one or more fractures along

3030-575: Is referred to as "seismic pumping". Minor intrusions in the upper part of the crust , such as dikes, propagate in the form of fluid-filled cracks. In such cases, the fluid is magma . In sedimentary rocks with a significant water content, fluid at fracture tip will be steam. Fracturing as a method to stimulate shallow, hard rock oil wells dates back to the 1860s. Dynamite or nitroglycerin detonations were used to increase oil and natural gas production from petroleum bearing formations. On 24 April 1865, US Civil War veteran Col. Edward A. L. Roberts received

3131-405: Is removed from the well, small grains of hydraulic fracturing proppants (either sand or aluminium oxide ) hold the fractures open. Hydraulic fracturing began as an experiment in 1947, and the first commercially successful application followed in 1949. As of 2012, 2.5 million "frac jobs" had been performed worldwide on oil and gas wells, over one million of those within the U.S. Such treatment

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3232-576: Is silica sand, though proppants of uniform size and shape, such as a ceramic proppant, are believed to be more effective. The fracturing fluid varies depending on fracturing type desired, and the conditions of specific wells being fractured, and water characteristics. The fluid can be gel, foam, or slickwater-based. Fluid choices are tradeoffs: more viscous fluids, such as gels, are better at keeping proppant in suspension; while less-viscous and lower-friction fluids, such as slickwater, allow fluid to be pumped at higher rates, to create fractures farther out from

3333-500: Is sometimes used to estimate the size and orientation of induced fractures. Microseismic activity is measured by placing an array of geophones in a nearby wellbore. By mapping the location of any small seismic events associated with the growing fracture, the approximate geometry of the fracture is inferred. Tiltmeter arrays deployed on the surface or down a well provide another technology for monitoring strain Microseismic mapping

3434-399: Is to completely characterize the induced fracture structure, and distribution of conductivity within a formation. Geomechanical analysis, such as understanding a formations material properties, in-situ conditions, and geometries, helps monitoring by providing a better definition of the environment in which the fracture network propagates. The next task is to know the location of proppant within

3535-539: Is uncertain, and there is some evidence that leakage may cancel out any greenhouse gas emissions benefit of natural gas relative to other fossil fuels . Increases in seismic activity following hydraulic fracturing along dormant or previously unknown faults are sometimes caused by the deep-injection disposal of hydraulic fracturing flowback (a byproduct of hydraulically fractured wells), and produced formation brine (a byproduct of both fractured and non-fractured oil and gas wells). For these reasons, hydraulic fracturing

3636-399: Is under international scrutiny, restricted in some countries, and banned altogether in others. The European Union is drafting regulations that would permit the controlled application of hydraulic fracturing. Fracturing rocks at great depth frequently become suppressed by pressure due to the weight of the overlying rock strata and the cementation of the formation. This suppression process

3737-570: Is very similar geophysically to seismology . In earthquake seismology, seismometers scattered on or near the surface of the earth record S-waves and P-waves that are released during an earthquake event. This allows for motion along the fault plane to be estimated and its location in the Earth's subsurface mapped. Hydraulic fracturing, an increase in formation stress proportional to the net fracturing pressure, as well as an increase in pore pressure due to leakoff. Tensile stresses are generated ahead of

3838-512: The Bakken formation in North Dakota. In contrast, a vertical well only accesses the thickness of the rock layer, typically 50–300 feet (15–91 m). Horizontal drilling reduces surface disruptions as fewer wells are required to access the same volume of rock. Drilling often plugs up the pore spaces at the wellbore wall, reducing permeability at and near the wellbore. This reduces flow into

3939-613: The Barnett Shale of north Texas. In 1998, the new technique proved to be successful when the first 90 days gas production from the well called S.H. Griffin No. 3 exceeded production of any of the company's previous wells. This new completion technique made gas extraction widely economical in the Barnett Shale , and was later applied to other shales, including the Eagle Ford and Bakken Shale . George P. Mitchell has been called

4040-628: The California Gold Rush , "... travelling across an elevated plateau almost covered by rock ..." After his 1852 expedition to explore the headwaters of the Red and Colorado Rivers, General Randolph Marcy wrote: "[not] a tree, shrub, or any other herbage to intercept the vision ... the almost total absence of water causes all animals to shun it: even the Indians do not venture to cross it except at two or three places." In his report for

4141-572: The Edwards Plateau near Big Spring, Texas . This geographic area stretches about 250 miles (400 km) north to south, and 150 miles (240 km) east to west, a total area of some 32,000 square miles (83,000 km ), larger than Indiana and 12 other states. It covers all or part of 33 Texas counties and four New Mexico counties. The area is susceptible to frequent dust storms because of its low relief, frequent turbulent winds, lack of vegetation, and loose topsoil. The landscape

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4242-843: The Great American Desert . The Canadian River forms the Llano's northern boundary, separating it from the rest of the High Plains. To the east, the Caprock Escarpment , a precipitous cliff about 300 feet (100 m) high, lies between the Llano and the red Permian plains of Texas; while to the west, the Mescalero Escarpment demarcates the eastern edge of the Pecos River valley. The Llano has no natural southern boundary, instead blending into

4343-668: The Horsehead Crossing of the Pecos River , then forked southward to the Comanche Springs where it divided, one part of the trail crossing the great river near Boquillas and the other at Presidio ." Rachel Plummer , while a captive of the Comanche in 1836, mentioned the "table lands between Austin and Santa Fe". Robert Neighbors and Rip Ford , guided by Buffalo Hump , blazed the "upper route" trail from San Antonio to El Paso in 1849 for emigrants during

4444-591: The Llano Estacado and the Edwards Plateau . As most often defined, the Spraberry includes portions of Irion , Reagan , Upton , Glasscock , Midland , and Martin Counties, although the underlying geologic unit also touches Dawson , Crockett , and Andrews Counties. Elevations are generally between 2,500 and 3,000 feet (910 m) above sea level, and the terrain varies from flat to rolling, with occasional canyons, known locally as "draws", cutting through

4545-646: The Staked Plains , is a region in the Southwestern United States that encompasses parts of eastern New Mexico and northwestern Texas . One of the largest mesas or tablelands on the North American continent, the elevation rises from 3,000 feet (900 m) in the southeast to over 5,000 feet (1,500 m) in the northwest, sloping almost uniformly at about 10 feet per mile (2 m/km). The Spanish name Llano Estacado

4646-525: The United States Army : When we were upon the high table-land, a view presented itself as boundless as the ocean. Not a tree, shrub, or any other object, either animate or inanimate, relieved the dreary monotony of the prospect; it was a vast-illimitable expanse of desert prairie . ... the great Sahara of North America . it is a region almost as vast and trackless as the ocean—a land where no man, either savage or civilized permanently abides ...

4747-530: The United States Environmental Protection Agency (EPA), hydraulic fracturing is a process to stimulate a natural gas, oil, or geothermal well to maximize extraction. The EPA defines the broader process to include acquisition of source water, well construction, well stimulation, and waste disposal. A hydraulic fracture is formed by pumping fracturing fluid into a wellbore at a rate sufficient to increase pressure at

4848-563: The "father of fracking" because of his role in applying it in shales. The first horizontal well in the Barnett Shale was drilled in 1991, but was not widely done in the Barnett until it was demonstrated that gas could be economically extracted from vertical wells in the Barnett. As of 2013, massive hydraulic fracturing is being applied on a commercial scale to shales in the United States, Canada, and China. Several additional countries are planning to use hydraulic fracturing . According to

4949-626: The Big Sandy gas field of eastern Kentucky and southern West Virginia started hydraulically fracturing the Ohio Shale and Cleveland Shale , using relatively small fracs. The frac jobs generally increased production, especially from lower-yielding wells. In 1976, the United States government started the Eastern Gas Shales Project , which included numerous public-private hydraulic fracturing demonstration projects. During

5050-538: The Llano Estacado as "open, but not exactly a desert". Robert G. Carter described it in 1871 while pursuing Quanah Parker with Ranald S. Mackenzie , "... all were over and out of the canyon upon what appeared to be a vast, almost illimitable expanse of prairie. As far as the eye could reach, not a bush or tree, a twig or stone, not an object of any kind or a living thing, was in sight. It stretched out before us-one uninterrupted plain, only to be compared to

5151-481: The Ogallala, which reflect today's arid conditions. Pleistocene rainfall over the flat terrain caused water to pond at the surface, resulting in a High Plains characteristic, innumerable round ponds called playa lakes . Spearing goes on to say, When the weather is dry, they are dusty, round, gray, usually unvegetated flats, as observed from the highway. But after a High Plains thunderstorm, water quickly fills

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5252-496: The Rocky Mountains. The economy of the Llano Estacado is predominantly agricultural, with farming of various crops prevalent, as is cattle ranching . Oil and gas production is also intense throughout the Llano Estacado making it one of the most productive petrochemical areas in the United States. Overuse of the aquifer in the past has persuaded some farmers to return to dryland crops, leading to less rainwater reaching

5353-499: The Spraberry retains about 90% of its original calculated reserves, largely due to the difficulty of recovery. As of 2009, there were approximately 9,000 active wells in the Spraberry Trend. 31°44′30″N 101°52′28″W  /  31.7416°N 101.8744°W  / 31.7416; -101.8744 Llano Estacado The Llano Estacado ( Spanish: [ˈʝano estaˈkaðo] ), sometimes translated into English as

5454-580: The US Army was fought on 28 September 1874 in the Battle of Palo Duro Canyon . Charles Goodnight described what it takes to be a scout: "... the trained ear should be able to tell the sound, whether it was made by man or beast or bird ... as a human voice echoes more than all others ... of course, on the Staked Plains we have not this advantage as there is nothing to create an echo." Today, most of

5555-430: The area's population is localized in the principal cities of Amarillo , Lubbock , Midland and Odessa , Texas. The vast majority of the area is rural , covered by large ranches and irrigated farms. Several small- to medium-sized towns do exist, however, including Andrews , Hereford , Plainview , Levelland , Big Spring, and Lamesa , Texas, and Hobbs , Clovis , and Portales , New Mexico. The Ogallala Formation

5656-802: The benefits of energy independence . Opponents of fracking argue that these are outweighed by the environmental impacts , which include groundwater and surface water contamination, noise and air pollution , the triggering of earthquakes , and the resulting hazards to public health and the environment. Research has found adverse health effects in populations living near hydraulic fracturing sites, including confirmation of chemical, physical, and psychosocial hazards such as pregnancy and birth outcomes, migraine headaches, chronic rhinosinusitis , severe fatigue, asthma exacerbations and psychological stress. Adherence to regulation and safety procedures are required to avoid further negative impacts. The scale of methane leakage associated with hydraulic fracturing

5757-695: The borehole from the surrounding rock formation, and partially seals off the borehole from the surrounding rock. Low-volume hydraulic fracturing can be used to restore permeability. The main purposes of fracturing fluid are to extend fractures, add lubrication, change gel strength, and to carry proppant into the formation. There are two methods of transporting proppant in the fluid – high-rate and high- viscosity . High-viscosity fracturing tends to cause large dominant fractures, while high-rate (slickwater) fracturing causes small spread-out micro-fractures. Water-soluble gelling agents (such as guar gum ) increase viscosity and efficiently deliver proppant into

5858-462: The casing. Using the fiber optics, temperatures can be measured every foot along the well – even while the wells are being fracked and pumped. By monitoring the temperature of the well, engineers can determine how much hydraulic fracturing fluid different parts of the well use as well as how much natural gas or oil they collect, during hydraulic fracturing operation and when the well is producing. For more advanced applications, microseismic monitoring

5959-439: The created fractures from closing after the fracturing treatment. Types of proppant include silica sand , resin-coated sand, bauxite , and man-made ceramics. The choice of proppant depends on the type of permeability or grain strength needed. In some formations, where the pressure is great enough to crush grains of natural silica sand, higher-strength proppants such as bauxite or ceramics may be used. The most commonly used proppant

6060-468: The decade-long fracking boom has led to lower prices for consumers, with near-record lows of the share of household income going to energy expenditures. Hydraulic fracturing is highly controversial. Its proponents highlight the economic benefits of more extensively accessible hydrocarbons (such as petroleum and natural gas ), the benefits of replacing coal with natural gas , which burns more cleanly and emits less carbon dioxide (CO 2 ), and

6161-649: The early 18th century, the Comanches expanded their territory into the Llano Estacado, displacing the Apaches who had previously lived there. The region became part of the Comancheria , a Comanche stronghold until the final defeat of the tribe in the late 19th century. The Comanche war trail extended from Llano Estacado to the Rio Grande into Chihuahua , "the trail ran southwesterly through Big Spring to

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6262-500: The fires of thousands of gas flares, and the people in Midland reported seeing what appeared to be a false sunrise in the east shortly after each sunset. In 1953 the Railroad Commission prohibited the wasteful practice, shutting down all wells in the field until a recovery system could be built. After a series of lawsuits and court battles, the Railroad Commission backed down, compromising with the operators by allowing them

6363-403: The first European to traverse this "sea of grass" in 1541, described it as follows: I reached some plains so vast, that I did not find their limit anywhere I went, although I traveled over them for more than 300 leagues ... with no more land marks than if we had been swallowed up by the sea ... there was not a stone, nor bit of rising ground, nor a tree, nor a shrub, nor anything to go by. In

6464-471: The first two commercial hydraulic fracturing treatments in Stephens County, Oklahoma , and Archer County, Texas . Since then, hydraulic fracturing has been used to stimulate approximately one million oil and gas wells in various geologic regimes with good success. In contrast with large-scale hydraulic fracturing used in low-permeability formations, small hydraulic fracturing treatments are commonly used in high-permeability formations to remedy "skin damage",

6565-402: The following New Mexico counties: Several interstate highways serve the Llano Estacado. Interstate 40 crosses the northern portion from east of Amarillo to Tucumcari, New Mexico. Interstate 27 runs north-south between Amarillo and Lubbock, while Interstate 20 passes through the southern portion of the Llano Estacado west of Midland and Odessa. Spanish conquistador Francisco Coronado ,

6666-402: The following: The most common chemical used for hydraulic fracturing in the United States in 2005–2009 was methanol , while some other most widely used chemicals were isopropyl alcohol , 2-butoxyethanol , and ethylene glycol . Typical fluid types are: For slickwater fluids the use of sweeps is common. Sweeps are temporary reductions in the proppant concentration, which help ensure that

6767-473: The formation process of mineral vein systems is particularly evident in "crack-seal" veins, where the vein material is part of a series of discrete fracturing events, and extra vein material is deposited on each occasion. One example of long-term repeated natural fracturing is in the effects of seismic activity. Stress levels rise and fall episodically, and earthquakes can cause large volumes of connate water to be expelled from fluid-filled fractures. This process

6868-425: The formation. Fluid is typically a slurry of water, proppant, and chemical additives . Additionally, gels, foams, and compressed gases, including nitrogen , carbon dioxide and air can be injected. Typically, 90% of the fluid is water and 9.5% is sand with chemical additives accounting to about 0.5%. However, fracturing fluids have been developed using liquefied petroleum gas (LPG) and propane. This process

6969-432: The fracture and the distribution of fracture conductivity. This can be monitored using multiple types of techniques to finally develop a reservoir model than accurately predicts well performance. Since the early 2000s, advances in drilling and completion technology have made horizontal wellbores much more economical. Horizontal wellbores allow far greater exposure to a formation than conventional vertical wellbores. This

7070-469: The fracture's tip, generating large amounts of shear stress . The increases in pore water pressure and in formation stress combine and affect weaknesses near the hydraulic fracture, like natural fractures, joints, and bedding planes. Different methods have different location errors and advantages. Accuracy of microseismic event mapping is dependent on the signal-to-noise ratio and the distribution of sensors. Accuracy of events located by seismic inversion

7171-408: The fracturing of formations in bedrock by a pressurized liquid. The process involves the high-pressure injection of "fracking fluid" (primarily water, containing sand or other proppants suspended with the aid of thickening agents ) into a wellbore to create cracks in the deep rock formations through which natural gas , petroleum , and brine will flow more freely. When the hydraulic pressure

7272-838: The gas economically. Starting in 1973, massive hydraulic fracturing was used in thousands of gas wells in the San Juan Basin , Denver Basin , the Piceance Basin , and the Green River Basin , and in other hard rock formations of the western US. Other tight sandstone wells in the US made economically viable by massive hydraulic fracturing were in the Clinton-Medina Sandstone (Ohio, Pennsylvania, and New York), and Cotton Valley Sandstone (Texas and Louisiana). Massive hydraulic fracturing quickly spread in

7373-523: The gas-producing limestone formation at 2,400 feet (730 m). The experiment was not very successful as the deliverability of the well did not change appreciably. The process was further described by J.B. Clark of Stanolind in his paper published in 1948. A patent on this process was issued in 1949 and an exclusive license was granted to the Halliburton Oil Well Cementing Company. On 17 March 1949, Halliburton performed

7474-448: The higher pressures are needed to push out larger volumes of fluid and proppant that extend farther from the borehole. Horizontal drilling involves wellbores with a terminal drillhole completed as a "lateral" that extends parallel with the rock layer containing the substance to be extracted. For example, laterals extend 1,500 to 5,000 feet (460 to 1,520 m) in the Barnett Shale basin in Texas, and up to 10,000 feet (3,000 m) in

7575-485: The implementation of enhanced recovery technologies, such as waterflooding. In the 1970s, as the price of oil went up, drilling and production proceeded; while Spraberry wells were never abundant producers, during periods of high prices they could provide dependable profits for oil companies, and the local economy entered its strongest period. In the 21st century, newer technologies such as carbon dioxide flooding have been used to increase production. Even with these advances,

7676-431: The internal shaly members or the overlying impermeable formation. Unlike many of the oil-bearing rocks of West Texas, however, the very low porosity and permeability hamper economic oil recovery. The rocks are naturally fractured, further complicating hydrocarbon flow. Shaly rocks make up 87% of the Spraberry, with the oil-bearing sands and siltstones present sometimes in thin layers between them. The best-producing zone

7777-674: The late 1970s to western Canada, Rotliegend and Carboniferous gas-bearing sandstones in Germany, Netherlands (onshore and offshore gas fields), and the United Kingdom in the North Sea . Horizontal oil or gas wells were unusual until the late 1980s. Then, operators in Texas began completing thousands of oil wells by drilling horizontally in the Austin Chalk , and giving massive slickwater hydraulic fracturing treatments to

7878-486: The length of the borehole is strictly controlled by various methods that create or seal holes in the side of the wellbore. Hydraulic fracturing is performed in cased wellbores, and the zones to be fractured are accessed by perforating the casing at those locations. Hydraulic-fracturing equipment used in oil and natural gas fields usually consists of a slurry blender, one or more high-pressure, high-volume fracturing pumps (typically powerful triplex or quintuplex pumps) and

7979-438: The minimum principal stress, and for this reason, hydraulic fractures in wellbores can be used to determine the orientation of stresses. In natural examples, such as dikes or vein-filled fractures, the orientations can be used to infer past states of stress . Most mineral vein systems are a result of repeated natural fracturing during periods of relatively high pore fluid pressure . The effect of high pore fluid pressure on

8080-493: The more reliable Ogallala water sands. Predictably, the consequent high dependency on groundwater has removed more water than is naturally replaced, raising concern for Panhandle citizens and planners as to future water supplies. The Pecos and Canadian rivers have eroded the Llano Estacado region down to the Triassic and Permian redbeds resulting in a distinctive color contrast besides separating it from source rocks in

8181-587: The ocean in its vastness." In August 1872, Mackenzie was the first to successfully lead troops across the Staked Plains preparatory to the Battle of the North Fork of the Red River . Billy Dixon described the area while hunting buffalo in June 1874: "All of us hunters acquainted with the habits of the buffalo knew that the herds would soon be coming north from the Staked Plains region where they had spent

8282-538: The plateau. Drainage is to the east, via the Concho River to the Colorado River . The climate is semi-arid . Native vegetation includes scrub and grasslands, with trees such as cottonwoods along the watercourses. Aside from activities associated with oil production, transport, and storage, predominant land use in the area includes ranching and farming. All of the Spraberry Trend oil fields produce from

8383-412: The playas. "Cotton, grain sorghum, corn, wheat, peanuts, sunflowers, grapes, vegetables, and cattle produced in the region literally go around the world. Their economic impact on our area is in the billions of dollars ... and the availability of water is a key factor influencing the region's agribusiness economy." One of the largest economic drivers on the Llano Estacado is in energy production, with

8484-422: The ponds, only later soaking into the underlying porous sandstones just below the surface to add to the groundwater in the Ogallala aquifer. Early pioneers depended dearly on water from these surface ponds for themselves and their livestock, considering how few streams are on the High Plains. But rains didn't always come, and the ponds dried up frequently. The 20th century has witnessed a concerted effort to tap

8585-507: The proppant, or sand may be labelled with Ir-192, so that the proppant's progress can be monitored. Radiotracers such as Tc-99m and I-131 are also used to measure flow rates. The Nuclear Regulatory Commission publishes guidelines which list a wide range of radioactive materials in solid, liquid and gaseous forms that may be used as tracers and limit the amount that may be used per injection and per well of each radionuclide. A new technique in well-monitoring involves fiber-optic cables outside

8686-583: The rate of frictional loss, which is relative to the distance from the well. Operators typically try to maintain "fracture width", or slow its decline following treatment, by introducing a proppant into the injected fluid – a material such as grains of sand, ceramic, or other particulate, thus preventing the fractures from closing when injection is stopped and pressure removed. Consideration of proppant strength and prevention of proppant failure becomes more important at greater depths where pressure and stresses on fractures are higher. The propped fracture

8787-480: The region experiencing significant activity for producing oil and natural gas associated with the Permian Basin . Additionally, solar and wind farms have proliferated on the Llano Estacado due to the region's dry and windy climate making it a favorable location for the production of renewable energy . Hydraulic fracturing Hydraulic fracturing is a well stimulation technique involving

8888-432: The same company drilled well Lee 2-D, which produced 319 barrels per day (50.7 m/d) – hardly a spectacular discovery, but enough to pique the interest of numerous independent operators looking for opportunity around Midland. In 1950 and 1951, several other independent oil companies drilled productive wells separated by great distances, establishing that the formation was at least 150 miles (240 km) long, and beginning

8989-647: The same period, the Gas Research Institute , a gas industry research consortium, received approval for research and funding from the Federal Energy Regulatory Commission . In 1997, Nick Steinsberger, an engineer of Mitchell Energy (now part of Devon Energy ), applied the slickwater fracturing technique, using more water and higher pump pressure than previous fracturing techniques, which was used in East Texas in

9090-417: The small amount of precipitation is lost to evaporation, making dryland farming difficult. The Texas State Historical Society states it covers all or part of 33 Texas counties, six fewer than as depicted by a US Geological Survey map, and four New Mexico counties. As depicted by a US Geological Survey map, the Llano Estacado includes all or part of these Texas counties: It also includes all or part of

9191-480: The target depth (determined by the location of the well casing perforations), to exceed that of the fracture gradient (pressure gradient) of the rock. The fracture gradient is defined as pressure increase per unit of depth relative to density, and is usually measured in pounds per square inch, per foot (psi/ft). The rock cracks, and the fracture fluid permeates the rock extending the crack further, and further, and so on. Fractures are localized as pressure drops off with

9292-409: The unusual reservoir, and began to employ a technique known as " hydrofracturing " – forcing water down wells at extreme pressure, causing the rocks to fracture further, resulting in increased oil flow. This was moderately successful, and development of the Spraberry continued, albeit with greatly diminished expectations for massive output. Yet another method of fracturing the rocks to increase production

9393-521: The unusual step of asking the Railroad Commission of Texas , the regulatory body which decided on well spacing and production quota, to require 80-acre (320,000 m), and then even 160-acre (0.65 km) spacing to allow each drilling site to be profitable. Many of the initial wells were abandoned in the next few years as they ran out of oil; modern enhanced recovery techniques, such as carbon dioxide injection, were not yet available. For

9494-408: The well is not overwhelmed with proppant. As the fracturing process proceeds, viscosity-reducing agents such as oxidizers and enzyme breakers are sometimes added to the fracturing fluid to deactivate the gelling agents and encourage flowback. Such oxidizers react with and break down the gel, reducing the fluid's viscosity and ensuring that no proppant is pulled from the formation. An enzyme acts as

9595-455: The wellbore. Important material properties of the fluid include viscosity , pH , various rheological factors , and others. Water is mixed with sand and chemicals to create hydraulic fracturing fluid. Approximately 40,000 gallons of chemicals are used per fracturing. A typical fracture treatment uses between 3 and 12 additive chemicals. Although there may be unconventional fracturing fluids, typical chemical additives can include one or more of

9696-515: The wellbores. Horizontal wells proved much more effective than vertical wells in producing oil from tight chalk; sedimentary beds are usually nearly horizontal, so horizontal wells have much larger contact areas with the target formation. Hydraulic fracturing operations have grown exponentially since the mid-1990s, when technologic advances and increases in the price of natural gas made this technique economically viable. Hydraulic fracturing of shales goes back at least to 1965, when some operators in

9797-580: The winter ... moved by that strange impulse that ... caused them to change their home and blacken the Plains with their countless, moving forms." Zane Grey , in his novel The Thundering Herd (1925), offered the following explanation for the name Llano Estacado: "Thet name Llano Estacado means Staked Plain," said the Texan. "It comes from the early days when the Spanish Trail from Santa Fe to San Antone

9898-542: The yucca plants that dot the plains. Leatherwood opines in the Handbook of Texas that such way markers could plausibly explain the origin of the name, but that the "comparison of cliff formations and palisades made by explorers argues more convincingly for the geological origin". In his Roadside Geology of Texas , Geologist Darwin Spearing also prefers the geological solution to the etymology: The 'Staked Plains' tale

9999-604: Was marked by 'palos,' or stakes. There was only two trails across in them days an' I reckon no more now. Only the Indians know this plain well an' they only run in heah to hide awhile. Water an' grass are plentiful in some parts, an' then there's stretches of seventy miles dry an' bare as a bone." In the latter part of the 19th century, the Llano was a refuge for the bands of Kiowas and Comanches who did not wish to be confined to reservations in Indian Territory , in present-day Oklahoma . One of their last battles against

10100-593: Was studied by Floyd Farris of Stanolind Oil and Gas Corporation . This study was the basis of the first hydraulic fracturing experiment, conducted in 1947 at the Hugoton gas field in Grant County of southwestern Kansas by Stanolind. For the well treatment, 1,000 US gallons (3,800 L; 830 imp gal) of gelled gasoline (essentially napalm ) and sand from the Arkansas River was injected into

10201-710: Was to pump a mixture of soap and kerosene, followed by a coarse-grained sand, also under intense pressure. During the initial boom period the Spraberry promoters carried out an aggressive campaign to bring in outside investment, making exorbitant claims of the potential easy profit with the vast reserves of oil. As every well drilled into the Spraberry Sands anywhere in the Midland Basin found oil, at least initially, it seemed at first that their claims were not completely without merit. Yet their tactics were not subtle: one group of promoters from Los Angeles brought in

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