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US 4,376,463 AGranted
Method of applying tensile stress to a casing
AssigneeStandard Oil Company (Indiana)
InventorsPhillip D. Pattillo, William H. Wadlington
Life of this patent
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Abstract
This is a method of cementing casing under tension. Internal pressure is applied to a casing string set in the borehole after cement has been placed between the casing and the borehole wall. This results in a lengthening of the string. Anchor means are next set in the well wall and pressure released prior to setting of the cement to leave the string with an additional tensile loading.
Claims5
A method of setting a string of casing in a wellbore comprising:
- (a) suspending the string of casing in the wellbore,
- (b) placing cement in at least a part of the annulus between the string of casing and the wall of the wellbore thereby surrounding a portion of the casing with cement,
- (c) longitudinally elongating the string of casing in a downward direction causing elongation of the said portion of casing, and
- (d) maintaining prior to the setting of said cement the longitudinal elongation of the portion of the string of casing surrounded by said cement.
1 more element
A method of setting a string of casing in a wellbore comprising:
- (a) suspending the string of casing in the wellbore,
- (b) placing cement in at least a part of the annulus between the string of casing and the wall of the wellbore,
- (c) longitudinally extending the string of casing in a downward direction while maintaining the upper end thereof in essentially a fixed position, and
- (d) anchoring, prior to the setting of said cement, the string of casing within the wellbore below the top level of said cement.
1 more element
A method of setting a string of casing in a wellbore comprising:
- (a) suspending the string of casing in the wellbore,
- (b) placing cement in at least a part of the annulus between the string of casing and the wall of the wellbore,
- (c) applying pressure to the interior of the string of casing to cause downward elongation of the string of casing,
- (d) anchoring the string of casing within the wellbore below the top level of said cement, and
- (e) releasing said pressure prior to the setting of said cement.
2 more elements
Dependencies are inferred from the claim text.