Plugged base pipe for sand control
First Claim
1. A well screen for separating particulated material from formation fluid comprising, in combination:
- an elongated, tubular mandrel having a longitudinal bore defining a production flow passage, said mandrel being radially intersected by longitudinally spaced flow apertures;
a fluid-porous, particulate-restricting member mounted on said mandrel and covering said flow apertures;
a protective shell mounted on said mandrel and having a tubular sidewall disposed about said fluid-porous, particulate-restricting member, said shell sidewall being radially intersected by a flow aperture; and
,a sacrificial plug secured to said shell sidewall and sealing said flow aperture.
2 Assignments
0 Petitions
Accused Products
Abstract
The flow apertures of a perforated mandrel are temporarily sealed by plugs which are made of a sacrificial material, for example, zinc, aluminum and magnesium. The sacrificial plugs prevent dirty completion fluid from passing through and in and out of the screen as it is run into the hole, thereby protecting the screen from plugging. During the time the screen mandrel is temporarily sealed by the sacrificial plugs, cleaning fluid is circulated through a work string and is returned through the annulus between the screen and the open well bore for removing filter cake, drilling debris and lost circulation material. After the annulus has been cleaned, the annulus is filled with an acid solution or caustic solution, which dissolves the sacrificial plugs. In an alternative embodiment, each sealing plug has a body portion and a stub portion which project into the mandrel bore. The sealing plug body portion is intersected by a vent pocket which is sealed by the stub portion. The screen mandrel flow apertures are opened by mechanically shearing the stub portion of each sealing plug with a milling tool run on a concentric tubing string.
179 Citations
17 Claims
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1. A well screen for separating particulated material from formation fluid comprising, in combination:
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an elongated, tubular mandrel having a longitudinal bore defining a production flow passage, said mandrel being radially intersected by longitudinally spaced flow apertures; a fluid-porous, particulate-restricting member mounted on said mandrel and covering said flow apertures; a protective shell mounted on said mandrel and having a tubular sidewall disposed about said fluid-porous, particulate-restricting member, said shell sidewall being radially intersected by a flow aperture; and
,a sacrificial plug secured to said shell sidewall and sealing said flow aperture. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A well screen for placement within a well bore comprising, in combination:
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an elongated mandrel having a tubular sidewall and longitudinally spaced flow apertures formed radially therethrough; a fluid-porous, particulate-restricting member mounted on said mandrel; and
,a sealing plug disposed in each flow aperture, respectively, each sealing plug having a body portion which dissolves in response to contact by an acid solution or caustic solution, and each sealing plug being capable of sealing operation without rupture with respect to a column of completion fluid above the screen during a well completion procedure. - View Dependent Claims (9, 10, 11)
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12. A sand screen for placement within a well bore comprising, in combination:
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an elongated mandrel having a tubular sidewall enclosing a production bore and longitudinally spaced flow apertures formed radially therethrough; a fluid-porous, particulate-restricting member mounted on said mandrel; and
,a sealing plug disposed in each flow aperture, respectively, each sealing plug having a body portion engaging said mandrel sidewall and having a stub portion projecting into said mandrel bore, said body portion being intersected by a vent pocket, and said vent pocket being sealed by said stub portion. - View Dependent Claims (13, 14)
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15. In the completion of a well wherein a well screen having a perforated mandrel is run through a well bore, the improvement comprising the steps:
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sealing each screen mandrel perforation with a sacrificial plug; pumping cleaning fluid through the annulus between the screen and the well bore for removing debris from the annulus; and
,after the annulus has been cleaned, removing the plugs. - View Dependent Claims (16, 17)
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Specification