Production packer
Encyclopedia
A production packer is a standard component of the completion hardware of oil or gas wells
Oil well
An oil well is a general term for any boring through the earth's surface that is designed to find and acquire petroleum oil hydrocarbons. Usually some natural gas is produced along with the oil. A well that is designed to produce mainly or only gas may be termed a gas well.-History:The earliest...

 used to provide a seal between the outside of the production tubing
Production tubing
Production tubing is a tube used in a wellbore through which production fluids are produced .Production tubing is run into the drilled well after the casing is run and cemented in place. Production tubing protects wellbore casing from wear, tear, corrosion, and deposition of by-products, such as...

 and the inside of the casing, liner, or wellbore wall.

Based on its primary use, packers can be divided into two main categories: production packers and service packers. Production packers are those that remain in the well during well production. Service packers are used temporarily during well service activities such as cement squeezing, acidizing, fracturing and well testing.

It is usually run in close to the bottom end of the production tubing and set at a point above the top perforations
Perforation (oil well)
A perforation in the context of oil wells refers to a hole punched in the casing or liner of an oil well to connect it to the reservoir. In cased hole completions, the well will be drilled down past the section of the formation desired for production and will have casing or a liner run in...

 or sand screens. In wells with multiple reservoir
Oil reservoir
A petroleum reservoir, or oil and gas reservoir, is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. The naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability...

 zones, packers are used to isolate the perforations for each zone. In these situations, a sliding sleeve
Sliding sleeve
A sliding sleeve is a standard component for the completion of an oil or gas well. Their main uses are to shut off flow from one or more reservoir zones or to regulate pressure between zones....

 would be used to select which zone to produce. Packers may also be used to protect the casing from pressure and produced fluids, isolate sections of corroded casing, casing leaks or squeezed perforations, and isolate or temporarily abandon producing zones. In waterflooding developments in which water is injected into the reservoir, packers are used in injection wells to isolate the zones into which the water must be injected.

There are occasions in which running a packer may not be desirable. For example, high volume wells that are produced both up the tubing and annulus will not include a packer. Rod pumped wells are not normally run with packers because the associated gas is produced up the annulus. In general, well completions may not incorporate a packer when the annular space is used as a production conduit.

A production packer is designed to grip and seal against the casing
Casing (oil well)
Casing is large diameter pipe that is assembled and inserted into a recently drilled section of a borehole and typically held into place with cement.-Purpose:Casing that is cemented in place aids the drilling process in several ways:...

 ID. Gripping is accomplished with metal wedges called "slips." These components have sharpened, carburized
Carburization
Carburizing, spelled carburising in the UK, is a heat treatment process in which iron or steel is heated in the presence of another material which liberates carbon as it decomposes. Depending on the amount of time and temperature, the affected area can vary in carbon content...

 teeth that dig into the metal of the casing. Sealing is accomplished with large, cylindrical rubber elements. In situations where the sealed pressure is very high (above 5,000 psi), metal rings are used on either side of the elements to prevent the rubber from extruding.

A packer is run in the casing on production tubing or wireline
Wireline
In the oil and gas industry, the term wireline usually refers to a cabling technology used by operators of oil and gas wells to lower equipment or measurement devices into the well for the purposes of well intervention and reservoir evaluation....

. Once the desired depth is reached, the slips and element must be expanded out to contact the casing. Axial loads are applied to push the slips up a ramp and to compress the element, causing it to expand outward. The axial loads are applied either hydraulically, mechanically, or with a slow burning chemical charge.

Most packers are "permanent" and require milling in order to remove them from the casing. The main advantages of permanent packers are lower cost and greater sealing and gripping capabilities.

In situations where a packer must be easily removed from the well, such as secondary recoveries, re-completions, or to change out the production tubing, a retrievable packer must be used. To unset the tool, either a metal ring is sheared or a sleeve is shifted to disengage connecting components. Retrievable packers have a more complicated design and generally lower sealing and gripping capabilities, but after removal and subsequent servicing, they can be reused.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK