“Liner” means a string of casing set and cemented which does not extend to surface. Liners are anchored or suspended inside the previous casing string and may serve the purpose of intermediate or production casing strings. Source: Division of Mineral Resources Management – Oil and Gas, Ohio Administrative Code, Chapter 1501:9, January 2012.
What is the difference between liner and casing?
The liner is a type of casing. The liner hanger pipe is generally used as the production casing at the bottom. The connection between the hanger pipe and the upper casing depends on the tail pipe hanger.
How are the liners suspended inside the casing string?
Contrarily to the other types of casing strings which are hanged at the surface, the liners are suspended inside the previous casing string by the liner hangers. The liner hangers consisted of slips which can be activated hydraulically or mechanically. Slips grip inside the previous string in order to support the weight of the liner.
What is a liner on a well?
A liner is a casing string that does not extend to the top of the well or to the wellhead. Liners are anchored or suspended from inside the previous casing string using a liner hanger. The liner can be fitted with special components so that it can be connected or tied back to the surface at a later time.
What is a liner on a drilling rig?
Liner is a casing string that does not extend back to the wellhead but instead is hung from another casing string. Liners are used instead of full casing strings to reduce cost, improve hydraulic performance when drilling deeper, allow the use of larger tubing above the liner top, and not represent a tension limitation for a rig.
What is the difference between a liner and casing?
Casing is very necessary for smooth drilling operations in deep and ERD wells so that hole collapsing may be got rid of. Liner is a string of casing which does not extend to the surface but is hung from inside the previous casing string and is cemented in place.
What is liner in drilling?
“Liner” means a length of casing used downhole as an extension to a previously installed casing string to case the hole for further drilling operations and/or for producing operations.
What is a liner in the oilfield?
1. n. [Drilling] A casing string that does not extend to the top of the wellbore, but instead is anchored or suspended from inside the bottom of the previous casing string. There is no difference between the casing joints themselves.
What are the different types of casing?
The five types of casing string are conductor casing, surface casing, intermediate casing, casing liner, and production casing.
Why is production liner preferred to casing?
First, Production casing Liners are used to isolate the producing interval from drilling and completion fluid properties necessary to control uphole formations. Second, It is perfect for lost circulation control and well control. Third, we use them to reduce costs.
What is liner lap?
The space between the liner hanger and the casing shoe is called the liner lap. Liner hangers can be set hydraulically, mechanically, or a mixture of the two. Most liners are cemented back to the liner hanger.
How do you run a liner?
0:169:43Liner Hanger from Baker Hughes - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe first plug is landed. Pressure is increased to the back side of the plug.MoreThe first plug is landed. Pressure is increased to the back side of the plug.
What is a casing shoe in drilling?
The Casing Shoe (also known as a Ring Bit) is a carbide-studded shoe, welded onto the lead piece of casing, thus converts your casing into a drill string. The ring style shoe cuts through boulders and hard formations as the casing rotates.
What is the type of liner that we run to repair existing damaged casing?
The scab liner is a section of casing that does not reach the surface. It is used to repair existing damaged casing.
What do you mean by casing?
Definition of casing 1 : something that encases : material for encasing: such as. a : an enclosing frame especially around a door or window opening. b : a metal pipe used to case a well.
Which is the longest casing?
Intermediate casing is usually the longest section of casing found in a well. The primary purpose of intermediate casing is to minimize the hazards that come along with subsurface formations that may affect the well.
What is surface casing?
“Surface casing—A string or strings of casing used to isolate the wellbore from fresh groundwater and to prevent the escape or migration of gas, oil or other fluids from the wellbore into fresh groundwater. The surface casing is also commonly referred to as the water string or water casing.
What is liner in well completion?
Liner completions are similar to open hole completions in that casing must be set prior to drilling the producing interval. The advantage of a liner completion is that the drilling fluid system can be changed and a nondamaging fluid used to drill the pay interval.
What is tubing and casing?
Tubing naturally has a smaller diameter than casing, except for the 4 1/2-inch diameter. An outer diameter of 114.3 mm (4 1/2 inches) is considered a threshold and can be either casing or tubing. Anything smaller is called tubing, anything larger is casing.
What is a casing shoe in drilling?
The Casing Shoe (also known as a Ring Bit) is a carbide-studded shoe, welded onto the lead piece of casing, thus converts your casing into a drill string. The ring style shoe cuts through boulders and hard formations as the casing rotates.
What is the type of liner that we run to repair existing damaged casing?
The scab liner is a section of casing that does not reach the surface. It is used to repair existing damaged casing.
What are casings and liners used for?
Casings and liners play an important role in the construction of drilled shafts, and special attention must be given to their selection and use. Except for surface casing or guides, the casings and liners that are described in this chapter are used for support of the drilled shaft excavation, and/or may serve as a structural element of the completed drilled shaft. Casings and liners are used in conjunction with rotary drilling or other techniques described in Chapters 4 and 5 for constructing drilled shafts.
What is a casing machine?
Casings are tubes that are relatively strong, usually made of steel, and joined, if necessary, by welding or, in some cases, bolting. Casings may also have special joints that allow torque and axial load to be transferred to the tip, such as those that are used with full depth casing machines.
Why do you need to extend casing below the base of a drilled shaft?
If the hole terminates in water-bearing soil with only a water head for stability, it may be necessary that the casing extend below the base of the final excavation to avoid instability at the base. However, this procedure may result in an annular zone of loosened soil at the base of the drilled shaft excavation.
How to advance casing?
The contractor may drive the casing in advance using a vibratory hammer, or using oscillator/rotator equipment.
What is temporary casing?
Temporary casing is used to stabilize the drilled shaft excavation and then removed after or during placement of fluid concrete. Contractors like to emphasize the fact that the casing that is used temporarily in the drilling operation is essentially a tool, so it is sometimes termed “temporary tool casing.”.
How thick should steel casing be?
Most steel casing has a wall thickness of at least 0.325 inches, and casings larger than 48 inch O.D. tend to have greater wall thicknesses. Installation with vibratory or impact hammers may require greater wall thickness than would be used for casing installed in an oversized hole. Most contractors rely on experience in the selection of casing wall thickness. However, if workers are required to enter an excavation, the temporary or permanent casing should be designed to have an appropriate factor of safety against collapse.
Why is it so hard to seal a casing?
An irregular hard surface will make the casing tend to deflect off alignment, break cutting teeth, and possibly bend the casing.
What is a well casing?
A well casing is basically the wall of the well. It protects the well's vertical length that sinks down through the ground to access the groundwater. Usually, the well casing is a cylinder shape, and it is typically made of a sturdy material to provide long-lasting protection. Often, a well casing is simply a large pipe of steel or sturdy plastic.
How are well liners repaired?
So, if you have a well casing that leaks, your well experts may simply install a liner in the damaged portion of the casing. If your liner is giving out, your well experts may simply replace it.
What is a rubber seal on a well?
The term may refer to a rubber seal that patches a hole in the casing (also called a packer) or a thin metal lining (also called a repair sleeve) that lines the entire interior of the casing. Either way, a liner provides a secondary line of defense when something goes wrong with the well casing.
How to tell if a well casing is contaminated?
Since the well casing's main job is to keep contaminants out of your well water, the signs that something has gone wrong tend to include water that smells or looks different. If you suspect your water is contaminated, stop using it until you have had a professional check your well.
Do you need to inspect a well casing?
You will also want to inspect your casing if your water's annual testing, recommended for all private water wells, produces abnormal results. Visible mechanical damage to the aboveground well casing is another red flag.
Can you repair a well casing?
However, a liner is not always the best option for well casing repair. Sometimes, your contractor can simply repair the part of the broken casing (especially if the broken section is above ground). If damage is severe and neither of these options are likely to work, your contractor may recommend drilling a new well.
Can you use steel casing for concrete wells?
In areas with certain geological characteristics (such as solid rock belowground), you may need to use a steel casing. However, other geological characteristics may allow for a plastic or even concrete well casing. Both of these alternate materials have the advantage that, unlike steel, they will not rust.
Why use liners instead of casing strings?
Liners are used instead of full casing strings to reduce cost, improve hydraulic performance when drilling deeper, allow the use of larger tubing above the liner top, and not represent a tension limitation for a rig. Liners can be either an intermediate or a production string.
What is casing in a well?
Casing is the major structural component of a well. It is a tubular steel product used to line the wellbore (maintain borehole stability), prevent contamination of water sands, isolate water from producing formations, and control well pressures during drilling, production, and workover operations. Casing provides locations for the installation ...
How deep should a surface casing be?
Because of this, the surface casing is always cemented to surface. Surface casing depths typically vary between 1000 and 3000 ft (300-900 m).
What is intermediate casing?
Intermediate casing is set to isolate unstable hole sections, lost-circulation zones, low-pressure zones, and production zones. It is often set in the transition zone from normal to abnormal pressure. The casing cement top must isolate any hydrocarbon zones.
Do wells have intermediate casing strings?
Some wells require multiple intermediate strings and some other wells do not have intermediate casing string.
What is a liner in a well?
A liner is a casing string that does not extend to the top of the well or to the wellhead. Liners are anchored or suspended from inside the previous casing string using a liner hanger. The liner can be fitted with special components so that it can be connected or tied back to the surface at a later time.
What is a production liner?
Production liners are set to the top of, or through, the completion interval. Drilling liners are set primarily to case off and isolate zones of lost circulation, highly overpressured zones, and sloughing shales, so drilling may proceed. Repair liners are used to isolate casing leaks and to repair damaged, worn, corroded, or deliberately perforated casing. A large number of wells are drilled without running liners.
What is continuous resin coating?
Continuous resin-rich coating on the inside surface of a pipe or fitting component, used to protect the laminate from chemical attack or to prevent leakage under stress.
What is pipe that does not extend from the surface?
Pipe that does not extend from the surface and is intended to line the walls of a drilled well.
What are the loads of casing?
There are several loads which have to be considered when designing a casing string. Casing can be exposed to different loads while installation, drilling next section and producing from the well. The loads depend on many factors: formation pore pressure, formation fracture gradient, temperature profile and also the fluid encountered while drilling through the production zone.
What is intermediate casing?
Many troublesome formations can be encountered during drilling operations till getting to the production zone. These troublesome formations have to be isolated by what it is called intermediate casing. The number of strings run as intermediate casing depends on the faced problems such as: lost circulation zones, unstable shale, squeezing salts and abnormally pressured zones.
Where should a casing hanger land?
When the casing shoe reaches the casing seat depth, the hanger should land on the casing housing. In some cases, pup joints of casing are needed to land the casing hanger at the shoulders into the spool. Using this type of casing can be risky when reaching the bottom of the wellbore is a difficult issue.
Why is cementing important?
It is tested that the cementing improves the collapse resistance of casing. Cementing in many cases is important for well integrity. Getting voids between formation and casing can allow for example to salt to move freely toward the casing and collapse it.
How many ranges of casing length are there?
The casing length is standardized by the API into three ranges:
Why is a float collar used?
It is placed between the two first joints. It is fitted with a float valve to prevent fluids to flow back into the casing while running. The float collar is also used as seat for cement plugs. The float collar also prevents cement U-tubing effect before the cement strengthens and hardens in the annulus.
What is the purpose of a blowout casing?
The function of this type of casing is sealing off the fresh water zones and providing a support for the blowout preventer (BOP). The setting depth of this casing has to be accurately designed in areas where high pressure is expected. If the surface casing is set higher than planned or the setting depth is underestimated, the formation at casing shoe cannot resist to the pressure exerted while circulating gas influx which can occurs during drilling the next section.
What is a liner hanger?
The liner hanger is a cementing tool used in the cementing process.Many layers of casing are dropped during the drilling process. The liner is a type of casing. The liner hanger pipe is generally used as the production casing at the bottom. The connection between the hanger pipe and the upper casing depends on the tail pipe hanger.
Why seal the top of a liner hanger?
A seal is required at the top of the liner hanger to prevent transfer of fluid or pressures from either direction.
What are the different types of liner hangers?
General Speaking,3 kinds of liner hangers are widely used in oil and gas well.The mechanical liner hanger and hydraulic liner hanger and Expandable liner hangers.
What is the size of a JC Petro liner hanger?
We,JC Petro, are liner hanger manufacture and factory with API 5CT certificate. The size from 4 1/2″ to 13 5/8″,from mechanical liner hanger to hydraulic liner hanger.We have exported our liner hanger to Russia,UAE,Colombia etc 12 countries. With good after sales services,we have got high reputation from our clients.
