Cementing casing strings in deep water offshore wells
AssigneeHalliburton Energy Services, Inc.
InventorsB. Raghava Reddy, Russell M. Fitzgerald
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Abstract
The present invention provides improved compositions and methods for cementing casing strings in deep water offshore formations penetrated by well bores. The methods are basically comprised of the steps of preparing a cement composition comprised of hydraulic cement, water, an environmentally degradable water reducing and dispersing additive, an environmentally degradable set retarding additive and an environmentally degradable compressive strength and set accelerating additive.
Claims19
An improved method of cementing a casing string in a deep water offshore formation penetrated by a well bore comprising the steps of:
- (a) preparing a cement composition comprised of a single hydraulic cement, sufficient water to form a pumpable slurry, an environmentally degradable water reducing and dispersing additive, an environmentally degradable set retarding additive selected from the group consisting of sodium lignosulfonate, calcium lignosulfonate and ammonium lignosulfonate, said set retarding additive being present in an amount in the range of from about 0.0165% to about 0.165% by weight of cement in said composition, and an environmentally degradable compressive strength and set accelerating additive;
- (b) placing said cement composition in the annulus between said casing and said well bore;
- and
- (c) allowing said cement composition to set into a hard impermeable mass therein.
An improved method of cementing a casing string in a deep water offshore formation penetrated by a well bore comprising the steps of:
- (a) preparing a cement composition comprised of a single hydraulic cement, sufficient water to form a pumpable slurry, a gas present in an amount sufficient to form a foam, an environmentally degradable foaming and foam stabilizing additive, an environmentally degradable water reducing and dispersing additive, an environmentally degradable set retarding additive and an environmentally degradable compressive strength and set accelerating additive;
- (b) placing said cement composition in the annulus between said casing and said well bore;
- and
- (c) allowing said cement composition to set into a hard impermeable mass therein.
Dependencies are inferred from the claim text.