Delayed thixotropic cement compositions and methods
AssigneeHalliburton Energy Services, Inc.
InventorsJan Pieter Vijn, Bach Dao
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Abstract
Delayed thixotropic cement compositions and methods of cementing in subterranean zones penetrated by well bores are provided. The novel cement compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and a water soluble delayed thixotropy imparting additive selected from the group consisting of carbonic acid and alkali metal carbonates.
Claims11
A method of cementing in a subterranean zone penetrated by a well bore comprising the steps of:
- (a) preparing a delayed thixotropic cement composition comprising a hydraulic cement, sufficient water to form a slurry and a water soluble delayed thixotropy imparting additive selected from the group consisting of carbonic acid and alkali metal carbonates;
- (b) pumping said cement composition into said zone;
- and
- (c) allowing said cement composition to set into a hard impermeable mass therein.
A method of cementing a pipe string in a well bore without substantial loss of cement into fractures, vugs and other highly permeable subterranean zones comprising the steps of:
- (a) preparing a delayed thixotropic cement composition comprising Portland cement, sufficient water to form a slurry and a water soluble delayed thixotropy imparting additive comprised of sodium carbonate present in an amount in the range of from about 0.5% to about 4% by weight of cement in said composition;
- (b) pumping said cement composition into the annulus between said pipe string and the walls of said well bore;
- and
- (c) allowing said cement composition to set into a hard impermeable mass therein.
Dependencies are inferred from the claim text.