Methods and compositions for sealing subterranean zones
AssigneeHalliburton Energy Services, Inc.
InventorsB. Raghava Reddy, Karen Luke
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Abstract
Methods and compositions for sealing subterranean zones penetrated by well bores are provided. The methods basically comprise the steps of introducing a sealing composition into the subterranean zone comprised of a hydraulic cement, sufficient water to form a slurry and a rapidly acting thixotropy providing gelling agent, and allowing the sealing composition to remain at rest in the zone whereby the sealing composition rapidly gels and then sets into a hard impermeable mass therein.
Claims26
A method of sealing a permeable subterranean zone penetrated by a well bore to prevent the uncontrolled flow of fluids into or from the zone comprising the steps of:
- (a) introducing a sealing composition into said subterranean zone comprised of a hydraulic cement selected from the group consisting of Portland cements, pozzolana cements, gypsum cements, slag cements and silica cements, sufficient water to form a slurry and a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. xH2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I,
- Mb is a trivalent metal ion having an oxidation state of III, and
- x is the number of moles of water of crystallization in the range of from 0 to 24, and
- (b) allowing said sealing composition to remain at rest in said zone whereby said sealing composition rapidly gels and then sets into a hard impermeable mass therein.
A method of sealing a permeable subterranean zone penetrated by a well bore to prevent the uncontrolled flow of fluids into or from the zone comprising the steps of:
- (a) introducing a sealing composition into said subterranean zone comprising Portland cement, sufficient water to form a slurry, and a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. xH2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I,
- Mb is a trivalent metal ion having an oxidation state of III, and
- x is the number of moles of water of crystallization in the range of from 0 to 24, and
- (b) allowing said sealing composition to remain at rest in said zone whereby said sealing composition rapidly gels and then sets into a hard impermeable mass therein.
A method of sealing a permeable subterranean zone penetrated by a well bore to prevent the uncontrolled flow of fluids into or from the zone comprising the steps of:
- (a) introducing a sealing composition into said subterranean zone comprising a hydraulic cement, sufficient water to form a slurry, a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. xH2O, wherein
- M2 is a monovalent metal ion having an oxidation state of I,
- Mb is a trivalent metal ion having an oxidation state of III, and
- x is the number of moles of water of crystallization in the range of from 0 to 24, and a viscosity reducing agent selected from the group consisting of sodium sulfate, potassium sulfate, sulfonated naphthalene-formaldehyde condensate, sulfonated acetone-formaldehyde condensate and sulfonated melamine-formaldehyde condensate, and
- (b) allowing said sealing composition to remain at rest in said zone whereby said sealing composition rapidly gels and then sets into a hard impermeable mass therein.
A method of sealing a permeable subterranean zone penetrated by a well bore to prevent the uncontrolled flow of fluids into or from the zone comprising the steps of:
- (a) introducing a sealing composition into said subterranean zone comprising a hydraulic cement, sufficient water to form a slurry, and a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. xH2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I,
- Mb is a trivalent metal ion having an oxidation state of III, and
- x is the number of moles of water of crystallization in the range of from 0 to 24, and a polymer that generates anionic carboxylate groups in said sealing composition and thereby provides enhanced thixotropic properties to said composition, and
- (b) allowing said sealing composition to remain at rest in said zone whereby said sealing composition rapidly gels and then sets into a hard impermeable mass therein.
An improved subterranean formation sealing composition comprising:
- Portland cement;
- sufficient water to form a slurry;
- and
- a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. 12H2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I, and
- Mb is a trivalent metal ion having an oxidation state of III.
An improved subterranean formation sealing composition comprising:
- a hydraulic cement selected from the group consisting of Portland cements, pozzolana cements, gypsum cements, slag cements, and silica cements;
- sufficient water to form a slurry;
- and
- a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. 12H2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I, and
- Mb is a trivalent metal ion having an oxidation state of III.
An improved subterranean formation sealing composition comprising:
- a hydraulic cement;
- sufficient water to form a slurry;
- a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. 12H2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I, and
- Mb is a trivalent metal ion having an oxidation state of III;
- and
- a viscosity reducing agent selected from the group consisting of sodium sulfate, potassium sulfate, sulfonated naphthalene-formaldehyde condensate, sulfonated acetone-formaldehyde condensate and sulfonated melamine-formaldehyde condensate.
An improved subterranean formation sealing composition comprising:
- a hydraulic cement;
- sufficient water to form a slurry;
- a rapidly acting thixotropy providing gelling agent selected from the group consisting of compounds of the formula MaMb(SO4)2. 12H2O, wherein
- Ma is a monovalent metal ion having an oxidation state of I, and
- Mb is a trivalent metal ion having an oxidation state of III;
- and
- a polymer that generates anionic carboxylate groups in said sealing composition and thereby provides enhanced thixotropic properties to said composition.
Dependencies are inferred from the claim text.