Methods of sealing expandable pipe in well bores and sealing compositions

A method of sealing an expandable pipe or pipe string in a well bore comprising the steps of:

• (a) providing a compressible foamed sealant composition comprised of a hydraulic cement, a rubber latex, a rubber latex stabilizer, a gas and a mixture of foaming and foam stabilizing surfactants;
• (b) placing said expandable pipe or pipe string in said well bore;
• (c) placing said compressible foamed sealant composition in the annulus between said well bore and said expandable pipe or pipe string;
• (d) allowing said foamed sealant composition to harden into an impermeable mass;
• and
• (e) expanding said expandable pipe or pipe string whereby said hardened foamed sealant composition is compressed.

A method of sealing an expandable pipe or pipe string in a well bore comprising the steps of:

• (a) providing a compressible foamed sealant composition comprised of calcium aluminate cement, a rubber latex comprised of a styrene/butadiene copolymer latex emulsion containing water in an amount of about 50% by weight of said latex and being present in said foamed sealant composition in an amount in the range of from about 80% to about 300% by weight of said cement therein, a rubber latex stabilizer comprised of a surfactant having the formula H(CH2)12-15(CH2CH2O)15SO3Na present in said sealant composition in an amount in the range of from about 3% to about 6% by weight of said rubber latex therein, nitrogen gas present in said foamed sealant composition in an amount in the range of from about 5% to about 35% by volume of said non-foamed sealant composition and a mixture of foaming and foam stabilizing surfactants comprised of about 63.3 parts by weight of an ethoxylated alcohol ether sulfate surfactant, about 31.7 parts by weight of a cocoyl amidopropyl betaine surfactant and about 5 parts by weight of a cocoyl amidopropyl dimethyl amine oxide surfactant present in said foamed sealant composition in an amount in the range of from about 4% to about 10% by volume of said rubber latex therein;
• (b) placing said expandable pipe or pipe string in said well bore;
• (c) placing said compressible foamed sealant composition in the annulus between said well bore and said expandable pipe or pipe string;
• (d) allowing said foamed sealant composition to harden into an impermeable mass;
• and
• (e) expanding said expandable pipe or pipe string whereby said hardened foamed sealant composition is compressed.

A compressible foamed sealant composition for sealing an expandable pipe or pipe string in a well bore comprising:

• a hydraulic cement;
• a rubber latex;
• a rubber latex stabilizer;
• a gas;
• and
• a mixture of foaming and foam stabilizing surfactants.

A method of sealing an expandable pipe or pipe string in a well bore comprising the steps of:

• (a) placing said expandable pipe or pipe string in said well bore;
• (b) placing a sealant composition in said well bore wherein said sealant composition remains competent when compressed in the annulus between said well bore and said expandable pipe or pipe string;
• (c) allowing said sealant composition to harden;
• and
• (d) expanding said expandable pipe or pipe string whereby said hardened sealant composition is compressed.

A method of sealing an expandable pipe or pipe string in a well bore comprising the steps of:

• (a) placing said expandable pipe or pipe string in said well bore;
• (b) placing a sealant composition in said well bore wherein said sealant composition remains competent when compressed in the annulus between said well bore and said expandable pipe or pipe string, wherein said sealant composition is comprised of a hydraulic cement, a rubber latex, a rubber latex stabilizer, a gas and a mixture of foaming and foam stabilizing surfactants;
• (c) allowing said sealant composition to harden;
• and
• (d) expanding said expandable pipe or pipe string whereby said hardened sealant composition is compressed.