kelly bushing oil and gas made in china

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Our company produces all kinds of bushings, including casing bushings, kelly bushings and so on. Casing bushings are manufactured with high-strength heat treated steel. They"re specially designed to work with NOV rotary equipment and handling tools. With interchangeable insert bowls, these casing bushings can accommodate casing sizes from 16 inches up to 42 inches in diameter. There are three standard types for choice. Models CU and CUL are solid bushings, while the Model CB is a split bushing. These bushings are available for 17 1/2 in to 49 1/2 in rotary tables. In the operation, casing bushings are inserted directly into the rotary table to ensure that the casing runs perfectly with the center of the hole.

As a professional China casing bushings, kelly bushings and other oil drilling tools manufacturer, Jiangsu Kayson Petrol- Machinery Co., Ltd becomes a first-level supply member of Chinese Petroleum & Natural Gas Consortium. At the same time, it"s also the member of China Petrochemical Material Resources Market. And it has achieved the right for products import and export.

Start shopping at Alibaba.com to discover wholesale kelly bushing at incredible prices.Browse through kelly bushing for any type of vehicle.Bearings can be produced from a broad variety of materials, such as different steel, rubber, plastic, brass, and ceramic. These materials, each having their own benefits that render them appropriate to specific operations, including noise level, mass, weight, capacity, and resistance, and a series of options to match your individual needs and requirements.

This particular type of rolling component has had a lengthy lifespan, originally made popular in bicycles then, automobiles. It decreases spinning rubbing while withstanding axial and radial loads and has the potential to be used across a broad spectrum of different industries, of which aerospace, agricultural and machinery, wagons and other automobiles, skateboards, and of course fidget spinners!

However, getting a bushing that is properly functioning is critical to a comfortable and smooth ride, as they maintain the car in good conditions. We have variously available bushings including, grounding bushing, polyurethane bushings, energy suspension bushings, brass bushings, and even drill bushings.Buy our selection of kelly bushing now. For those of you who are looking for quality wholesale kelly bushing at a bargain price, well then you should look no further! At Alibaba.com, you may find a great array of quality automotive accessories and everything at an awesome price.

Through the rotation of four rolls,the friction between rolls and kelly pipes is reduced to extend service life. Change different rollers to match with different squares and hexagonal kelly pipes and connect with different rotary tables. ,Ltd with perfect attitude, product and service, is going to make further development together with customers at home and abroad .

Roller Kelly Bushings can be classed as two types based on different ways of drive, square drive and pin drive. Also they can be classed as three types based on different style, heavy, medium and light-duty. They are used for 17.1/2 to 49.1/2inch rotary tables. They are designed and manufactured according to API Spec 7K.

n: the recording of the natural or induced radioactive characteristics of subsurface formations. A radioactivity log, also known as a radiation log or a nuclear log, normally consists of two recorded curves: a gamma ray curve and a neutron curve. Both help to determine the types of rocks in the formation and the types of fluids contained in the rocks.

n: the closing and sealing component on a blowout preventer. One of three types—blind, pipe, or shear—may be installed in several preventers mounted in a stack on top of the wellbore. Blind rams, when closed, form a seal on a hole that has no drill pipe in it; pipe rams, when closed, seal around the pipe; shear rams cut through drill pipe and then form a seal.

n: a tool used in drilling to smooth the wall of a well, enlarge the hole to the specified size, help stabilize the bit, straighten the wellbore if kinks or doglegs are encountered, and drill directionally.

n: a pump consisting of a piston that moves back and forth or up and down in a cylinder. The cylinder is equipped with inlet (suction) and outlet (discharge) valves. On the intake stroke, the suction valves are opened, and fluid is drawn into the cylinder. On the discharge stroke, the suction valves close, the discharge valves open, and fluid is forced out of the cylinder.

n: after the initial completion of a well, the action and techniques of reentering the well and redoing or repairing the original completion to restore the well’s productivity.

n: a subsurface, porous, permeable or naturally fractured rock body in which oil or gas are stored. Most reservoir rocks are limestones, dolomites, sandstones, or a combination of these. The four basic types of hydrocarbon reservoirs are oil, volatile oil, dry gas, and gas condensate. An oil reservoir generally contains three fluids—gas, oil, and water—with oil the dominant product. In the typical oil reservoir, these fluids become vertically segregated because of their different densities. Gas, the lightest, occupies the upper part of the reservoir rocks; water, the lower part; and oil, the intermediate section. In addition to its occurrence as a cap or in solution, gas may accumulate independently of the oil; if so, the reservoir is called a gas reservoir. Associated with the gas, in most instances, are salt water and some oil. Volatile oil reservoirs are exceptional in that during early production they are mostly productive of light oil plus gas, but, as depletion occurs, production can become almost totally completely gas. Volatile oils are usually good candidates for pressure maintenance, which can result in increased reserves. In the typical dry gas reservoir natural gas exists only as a gas and production is only gas plus fresh water that condenses from the flow stream reservoir. In a gas condensate reservoir, the hydrocarbons may exist as a gas, but, when brought to the surface, some of the heavier hydrocarbons condense and become a liquid.

n: the process in which reservoir fluids are caused to flow out of the reservoir rock and into a wellbore by natural energy. Gas drive depends on the fact that, as the reservoir is produced, pressure is reduced, allowing the gas to expand and provide the principal driving energy. Water drive reservoirs depend on water and rock expansion to force the hydrocarbons out of the reservoir and into the wellbore. Also called natural drive energy.

n: oil in place in the reservoir; retained in a reservoir as residual gas saturation is an inverse function of the pressure, due to the physics of gas.

n: the recording of the resistance of formation water to natural or induced electrical current. The mineral content of subsurface water allows it to conduct electricity. Rock, oil, and gas are poor conductors. Resistivity measurements can be correlated to formation lithology, porosity, permeability, and saturation and are very useful in formation evaluation.

n: the course of drilling fluid downward through the annulus and upward through the drill stem, in contrast to normal circulation in which the course is downward through the drill stem and upward through the annulus. Seldom used in open hole, but frequently used in workover operations.

n: the area immediately around the rotary table and extending to each corner of the derrick or mast—that is, the area immediately above the substructure on which the rotary table, and so forth rest.

n: a type of chain that is used to transmit power by fitting over sprockets attached to shafts, causing rotation of one shaft by the rotation of another. Transmission roller chain consists of offset links, pin links, and roller links.

n: the machine used to impart rotational power to the drill stem while permitting vertical movement of the pipe for rotary drilling. Modern rotary machines have a special component, the rotary or master bushing, to turn the kelly bushing, which permits vertical movement of the kelly while the stem is turning.

n: a drilling method in which a hole is drilled by a rotating bit to which a downward force is applied. The bit is fastened to and rotated by the drill stem, which also provides a passageway through which the drilling fluid is circulated. Additional joints of drill pipe are added as drilling progresses.

n: a worker on a drilling or workover rig, subordinate to the driller, whose primary work station is on the rig floor. Sometimes called floorhand, floorman, rig crew member, or roughneck.

n: a length of pipe whose bottom edge is serrated or dressed with a hard cutting material and that is run into the wellbore around the outside of stuck casing, pipe, or tubing to mill away the obstruction.

Please send us your inquiry with detail item description or with Model number. If there is no packing demand we take it as our regular exported standard packing. We will offer you an order form for filling. We will recommend you the most suitable model according to information you offered.

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An adapter that serves to connect the rotary table to the kelly. The kelly bushing has an inside diameter profile that matches that of the kelly, usually square or hexagonal. It is connected to the rotary table by four large steel pins that fit into mating holes in the rotary table. The rotary motion from the rotary table is transmitted to the bushing through the pins, and then to the kelly itself through the square or hexagonal flat surfaces between the kelly and the kelly bushing. The kelly then turns the entire drillstring because it is screwed into the top of the drillstring itself. Depth measurements are commonly referenced to the KB, such as 8327 ft KB, meaning 8327 feet below the kelly bushing.

Pin drive bushingsPin drive bushings consist of lower body half, upper body half, roller and roller pin, etc. when the bushing is installed to square kelly or hex kelly, the square part of the lower body half can be fitted in the square of the master bushing. When operating, the rotary table drives master bushing and master bushing drives roller kelly bushings ...

Square drive bushingSquare drive bushing is also referred to as roller bushing or roller kelly bushing. This roller bushing is an essential drilling tool. Square drive bushing is used for 17 1/2-49 1/2 inch rotary tables. It"s designed and manufactured according to API Spec 7K. The roller kelly bushing works with master bushing to drive dril...

This roller kelly bushing is an essential drilling tool. The bushings are designed with two drive methods, i.e. square rolling and pin shaft rolling. And according to type, there are heavy, medium and light-duty kelly bushings. The roller kelly bushing can be equipped with turntable slips to drive the square or hexagon kelly bar.

Kelly bushings consist of top cover, base, axis, needle bearing, sealing body, roller, binding bolt, and refuel cup. The needle bearing within the roller is installed on axis whose both ends are compact between top cover and base. The refuel cup lying on axis end injects grease into needle bearing at regular intervals. In order to prevent the sealing body from penetrating and protect the needle bearing, the inner-outer O type circle must be installed on the both ends of the roller. Fasten pin lying on the top of sealing body prevents it from rotating, and inlays are inside seam allowance of up base.

To produce kelly bushings and other drilling tools, the company possesses strong technical force, excellent production equipments and complete test facilities. And we"re focusing on new products making and market expanding all the time. Now Jiangsu Saifu Petrol- Machinery Co., Ltd becomes a first-level supply member of Chinese Petroleum & Natural Gas Consortium. At the same time, it"s also the member of China Petrochemical Material Resources Market.

The global kelly drive market was valued at $1.6 billion in 2021, and is projected to reach $2.3 billion by 2031, growing at a CAGR of 3.7% from 2022 to 2031.

Report Key HighlightersThe kelly drive market is consolidated in nature with few players such as NOV Inc., SANY Group, BAUER Maschinen GmbH (Subsidiary of BAUER Group), Jereh Global Development LLC (As a Subsidiary of Jareh Group) and Liebherr-International Deutschland GmbH. that hold significant share of the market.

The study covers in-depth analysis of 16 countries from different regions including North America, Europe, Asia-Pacific, and LAMEA. In addition, country-wise data of every country has been provided for better understanding of kelly drive market dynamics in every country.

A kelly drive is a particular kind of well drilling tool which uses a section of pipe with a polygonal or splined outer surface and feeds it through a rotary table and matching kelly (mating) bushing which have the same shape or splines. The Kelly is a long, four- or six-sided steel bar having a hole bored through the center to allow drilling fluid to pass through. The kelly bushing allows the drill string to be lifted or lowered while it rotates by transferring rotating motion from the rotary table or kelly bushing to the drill string. Crewmembers make up several attachments to the kelly. The attachments include the upper kelly cock, the lower kelly cock (drill pipe safety valve), and the kelly saver sub.

Kelly drilling is one of the most used dry rotary drilling techniques. The kelly drive is used to create large-diameter bored piles (from a size of approx. 500 mm). With the increasing drilling activities is booting the kelly drive market share in coming year. The kelly drive works with almost any kind of rock and soil. According to kelly drive market forecast, the demand for short rotary drilling instruments, such as augers, core barrels, buckets, and specialized drilling tools which are used to move the dirt will be more in the market. The drill rod which is also known as a kelly bar, is a typical component of this drilling technique. The strong kelly bars enables deep drilling and help in boosting the kelly drive market trend in forecast period.

Globally, there has been a surge in oil exploration activity, which is driving the demand for kelly drive in rig and drilling industry. Apart from the pandemic time, a boom in exploration has tripled over the last five years. Kelly drive market analysis showcase the owing to a global boom in exploration of oil reserves, several oil companies are getting into the rig sector. With the ongoing expansion in petroleum products, large oil extraction companies are contracting with drilling equipment manufacturers for the rent and sale of drilling equipment. Oil exploration companies and equipment companies collaborate to provide offshore support services that can increase production. Factor such as oil exploration activities is likely to boost the market for kelly drive in near future.

Advances in technology and equipment have enabled more oil and natural gas to be recovered from the length of each well, improving production and reducing the environmental footprint of energy production. Kelly drive is cheaper however, technology is slow, inefficient, and unsafe as compared to the other technology which are present or coming in the market. These factors may restrain customers from using kelly drive; thus, hampering the market growth.

With combination of seismic surveys and drilling wells, companies are doing the search of oil reserve and deposits beneath the surface of the earth. Exploration projects can be expensive, time-consuming, and risky, drilling a well may cost tens of millions of dollars. Several factors are considered the number of wells to be drilled, recovery method, type of installation to be used, separation systems for the gas & fluids, and how the oil and gas will be transported to a processing facility. High demand for the petroleum products in the market resulting into several new excavations projects in different regions. This factor is anticipated to increase the sales of kelly drive; thus, creating lucrative kelly drive market opportunities.

The kelly drive market is segmented into product type, and region. On the basis of product type, the market is bifurcated into cleaners, braking oil, grease and lubes, degreaser, and others. Region-wise, the market is studied across North America, Europe, Asia-Pacific, and LAMEA.

In 2021, the square kelly segment was the largest revenue generator, and is anticipated to grow at a CAGR of 3.6% during the forecast period. With the increasing horizontal drilling operations result in increasing demand for square kelly in the market. To increase the output from a single well, drilling square kelly equipment are being used frequently in the market. Square Kelly is advantageous for end-users, however equipment can be used for both onshore and offshore drilling operations. Drilling activities are becoming more challenging which are demanding the high quality of kelly equipment. Several oil firms engage in new types of drilling on land, such as horizontal well drilling which covers a significantly larger area under the earth. With the increasing horizontal well drilling creates the opportunity for square kelly segment in global kelly drive market.

In 2021, the kelly bar segment was the largest revenue generator, and is anticipated to grow at a CAGR of 4.0% during the forecast period. With the increasing number of excavation projects and finding of deep oil reserves will increase the demand for kelly bars in the market. Companies are entering into the agreement for the drilling operations which is driving the kelly bars market. Today, reserves are found very deep under the land of sea which require the high strength bars for handling the pressure. Vertical and horizontal drilling activities are increasing which is increasing the demand for different shapes of kelly bars.

In 2021, the onshore segment was the largest revenue generator, and is anticipated to grow at a CAGR of 3.8% during the forecast period. The rise in production activities and decrease in non-productive time are anticipated to propel the market for the onshore segment during the coming years. The onshore oilfields in North America and LAMEA have witnessed a high market share, regions mainly focus on efficiency improvement, decline in non-productive drilling activity time, and enhancement in health, safety, and environment aspects while drilling.

The North America kelly drive market size is projected to grow at the highest CAGR during the forecast period. The region is experiencing more drilling activities of oil and gas extraction as the demand for oil-related goods rises worldwide. Kelly drive equipment is particularly helpful for drilling through hard rock and getting to the oil deposits. The Kelly Drive can be used to reduce operational expenses in drilling operations. For field operators and engineers, it ensures long-term project success and a high rate of return.

LAMEA was the second-largest contributor in terms of revenue in the global kelly drive market in 2021, and is anticipated to grow at a CAGR of 3.8% during the forecast period. Accelerated investment across the upstream sector along with crude oil price recovery will foster the drilling activities in the region. Robust growth in petrochemical products demand along with increase in industrial and commercial activities across the developing economies will boost the kelly drive market growth in LAMEA region.

For instance, The natural gas production in Saudi Arabia has been planned to increase by two-fold in the coming decade, which is expected to result in increased drilling activities related to gas production.

The leading players operating in the global kelly drive market include, NOV Inc., SANY Group, BAUER Maschinen GmbH (Subsidiary of BAUER Group), Jereh Global Development LLC (As a Subsidiary of Jareh Group) and Liebherr-International Deutschland GmbH, Bridges Equipment LTD, Lake Petro., TEXAS INTERNATIONAL OILFIELD TOOLS, LTD, Goldman, Tianhe Oil Group Co. Ltd., XI"AN KINGWELL OILFIELD MACHINERY CO.,LTD, El Didi Group.

Key benefits for stakeholdersPorter’s five forces analysis helps analyze the potential of buyers & suppliers and the competitive scenario of the industry for strategy building.

It outlines the current Kelly drive market trends and future estimations from 2021 to 2031 to understand the prevailing opportunities and potential investment pockets.

The invasion of Russia has further worsened an already precarious scenario for the energy and drilling markets, notably in Europe. To minimize the possibility of an interruption in Russian oil and gas supply, oil and gas corporations must collaborate with governments. In longer term, the sector needs to increase its adaptability and relevance in a rapidly evolving energy environment. The scenario brought about by the conflict between Russia and Ukraine influences the Kelly Drive market as well. Many projects that were previously underway in the nations are now on hold, and new projects are being delayed, which has slowed the market"s expansion in recent years.

April 15 (Reuters) - Global oil companies are increasingly turning to China for services and equipment, attracted by lower costs and a newly acquired expertise that is challenging more established rivals.

State-run and privately controlled Chinese rig makers, oil and gas services and engineering firms are showing up in the supply chain everywhere from the Middle East, the North Sea and North America to frontier areas like Mozambique.

Helped by strong government support, plentiful labour and an abundant supply of raw materials like steel, China could become a major offshore oil equipment manufacturing hub in less than 10 years, industry executives say, just like Singapore and South Korea overtook the United States and Europe in the 1990s.

“The Chinese provide products with better value,” said Scott Darling, Hong-Kong based head of Asia oil and gas research at JPMorgan, which hosted an investor tour of the Middle East last month to study the competitiveness of Chinese energy equipment and services suppliers. “And they are experts in managing supply chains, thanks to their domestic experiences.”

The rise of Chinese energy equipment manufacturers and services firms overseas, partly fuelled by the rapid expansion of state energy giants, is putting pressure on established companies including Singapore oil rig makers Keppel Corp and Sembcorp Marine, and land drilling giant National-Oilwell Varco Inc (NOV).

To stay ahead, both Keppel and Sembcorp are increasingly building more sophisticated equipment, an area where Chinese firms still lack expertise. <^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ GRAPHIC-China"s offshore rig orders: link.reuters.com/cen38v ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Leading the Chinese overseas expansion are state-controlled shipyards and units of state giants China National Petroleum Corp (CNPC), parent of PetroChina , Sinopec Group and China National Offshore Oil Corp (CNOOC).

Chinese companies won over half the global orders for jackup rigs last year, up from around a third between 2008 and 2012, data from IHS Petrodata showed.

In the area of land drilling equipment, a number of privately run companies have emerged as major overseas players. These include Honghua Group Ltd, the second-largest land rig manufacturer globally with 80 percent of revenue driven by overseas orders, and Hilong Holding Ltd, which started its overseas foray in 2005 and is now the world’s second-largest drill pipe maker after Houston-based NOV.

“Drill pipes are crucial to oil producers. Previously their drilling schedules were sort of dictated by just one company, NOV,” Amy Zhang, Hilong’s chief strategy officer, told Reuters.

Manufacturing energy equipment is an expensive, labour-intensive and lengthy process, and with global energy firms trying to cut costs, the affordability of the services offered by Chinese firms has trumped their relative lack of experience.

Exxon Mobil Corp, Total SA, BP PLC and Royal Dutch Shell have all pledged to cap spending due to pressure from their shareholders, who want more generous payouts before cyclical oil prices start heading lower.

China’s oil and petrochemical equipment exports were averaging at around $18 billion a year in the past few years, equivalent to the annual capital spending budget of a mid-sized international oil company, industry data showed.

Shell is currently the biggest buyer of equipment and services from China among its foreign rivals. Its China procurement jumped to $3 billion last year from $1.9 billion in 2012 and $1 billion a year earlier, Shell China spokesman Jiangtao Shi said, adding that one third of its 2013 China procurement was earmarked for projects outside China.

COSCO Corp, China State Shipbuilding Corp , China Shipbuilding Industry Corp, Yantai CIMC Raffles and Offshore Oil Engineering Corp can build a jack-up rig for $170-180 million, significantly lower than the $200-220 million price tag for the same rig built in Singapore.

Chinese manufacturers can also make land rigs, drilling pipes, bits, modules, pumps and valves at up to half the price of the same equipment made elsewhere. Prices are so competitive that the United States in 2012 slapped hefty anti-dumping duties on imports of Chinese seamless steel pipes, including pipes used for oil and gas drilling.

“We export a lot of petroleum and petrochemical gears. Most of them are crude and clunky stuff but we make money from them,” Zhang Kang, senior consultant at Sinopec, told Reuters. “We also try to make more sophisticated equipment.”

As relative newcomers, Chinese companies remain far behind in terms of making sophisticated tools like deepwater rigs and hydraulic fracturing, or fracking, equipment which is used to extract natural gas trapped in shale formations.

They also lag in building complicated petrochemical and liquefied natural gas plants, a business still dominated by Japanese, Korean and European firms.

The Chinese firms are rapidly gaining know-how, helped by global firms such as Shell which is working to improve the technical qualifications and standards of its Chinese suppliers to make them part of its global purchasing network.

Shell has started using robot hydraulic fracturing equipment made at its China joint venture with CNPC at projects in China and Australia, with the aim of deploying the kit to Canada later this year, Shell’s Shi said.

The JOTKB MODEL 27 PDHD OR 20 PDHD are developed for pin drive master bushing for rotary table sizes from 27-1/2" to 49-1/2" having 25-3/4" and 23" dia pin center. This unit is used for heavy duty drilling operations and high torque conditions on off shore as well as on shore drilling operations, and handle Kelly sizes from 3" to 6" Square or Hexagonal.

The kelly is a primary link between the drilling rig’s surface equipment and the bit, and is therefore a critical component of the rotary system. Although top drive systems have replaced kelly/rotary table combinations on many rigs, some knowledge of their manufacture and operation is useful.

Their angled surfaces, or drive flats, are designed to fit into a drive roller assembly on the kelly bushing, so that as the rotary table turns to the right, the kelly turns with it. To allow for normal right-hand rotation of the drill string, kellys have right-hand threads on their bottom connections and left-hand threads on their top connections.

The American Petroleum Institute has established manufacturing and design standards for kellys, and has included them in the follwoing publications:API RP 7G, Recommended Practice for Drill Stem Design and Operating Limits.

For a kelly to be efficient in turning the drill string, the clearance between its drive flat surfaces and the rollers in the kelly bushing must be kept to a minimum. Kellys most often wear out due to a rounding-off of the drive corners, as shown in Figure 1 (new kelly with new drive assembly) and Figure 2 (worn kelly with worn drive assembly).

As rounding progresses, it further accelerates the wear process by increasing the clearance and the contact angle between the drive flats and the rollers.

For minimal rounding, there must be a close fit between the kelly and the roller assembly, with the rollers fitting the largest spot on the kelly flats. Manufacturing techniques and rig operating practices play important roles in determining this fit.

Both square and hexagonal kellys are manufactured either from bars with an “as-forged” drive section, or from bars with fully-machined drive sections. Forged kellys are cheaper to manufacture. But machined kellys tend to last longer because:Unlike forged kellys, machined kellys are not subject to the metallurgical process of decarburization, which leaves a relatively soft layer of material on the drive surface that can accelerate the rounding process and increase the potential for fatigue cracks;

To minimize rounding, rig personnel should follow these guidelines (Brinegar, 1977):Always use new drive-bushing roller assemblies to break in a new kelly.

Frequently inspect and periodically replace drive assemblies to ensure that clearance and contact angle between the kelly and the rollers is held to a minimum;

Fatigue failures are seldom a problem with kellys because of the high-quality steels used in their manufacture. Nevertheless, kellys should be regularly inspected for cracks and other signs of wear, particularly within the threaded connections, in the areas where the flats join the upper and lower upsets and in the center of the drive section.

The areas of highest stress concentration — and therefore the most likely locations for fatigue failure — are the areas where the drive flats join the upper and lower upsets.

In general, the stress level for a given tensile load is less in the drive section of a hexagonal kelly than in the drive section of a square kelly of comparable size. Hexagonal kellys are thus likely to last longer than square kellys before failing under a given bending load.

Kellys can become crooked or bent due to improper handling. Examples of mishandling include dropping the kelly, misaligning it in the rathole and thereby exerting a side pull, using poor tie-down practices during rig moves, not using the kelly scabbard and improper loading or unloading techniques. Depending on where a bend is located, it may cause fatigue damage not only to the kelly but to the rest of the drill string, and can also result in uneven wear on the kelly bushing.

Unusual side motions or swaying of the swivel are good indicators of a crooked kelly. A good field service shop has equipment for straightening bent kellys, making this an easily-corrected problem.

A kelly saver subshould always be run between the kelly and the top joint of drill pipe. This protects the kelly’s lower connection threads from wear, as joints of drill pipe are continually made up and broken out. A saver sub is much less expensive and much easier to replace than the kelly itself, and it can also be equipped with a rubber protector to help keep the kelly centralized and to protect the top joint of casing against wear.

A kelly cock is a valve installed above or below the kelly, which prevents fluid from escaping through the drill string if the well should begin to flow or “kick.” As an extra well control precaution, an upper kelly cock (having left-hand threads) should be installed directly above the kelly, while a lower kelly cock (having right-hand threads) should be installed below the kelly. Installing two kelly cocks ensures that at least one of them is always accessible, regardless of the kelly’s position.

Automatic check valves, designed to close when the mud pumps are shut off, are also available, and can be installed below the kelly to prevent mud from spilling onto the rig floor during connections.