Set retarded cement compositions and well cementing methods
AssigneeHalliburton Company
InventorsJerry D. Childs, Freddie L. Sabins
Life of this patent
Estimating the term…
Abstract
Set retarded cement compositions for cementing across a zone or zones in a well having enhanced compressive strength development after placement across the zone or zones are provided. The cement compositions are comprised of hydraulic cement, sufficient water to form a pumpable slurry, one or more set retarders and a delayed retarder neutralizer comprised of one or more titanium chelates. Methods of cementing utilizing the compositions are also provided.
Claims16
A method of cementing a subterranean zone penetrated by a wellbore comprising the steps of:
- forming a pumpable set retarded thixotropic cement slurry having enhanced compressive strength development after placement across said zone or zones comprised of hydraulic cement, water, one or more retarders present in said slurry in an amount sufficient to retard the set of said slurry until after placement thereof, a crosslinkable material present in said slurry in an amount sufficient to provide thixotropic properties and gel strength development when crosslinked to said composition, and a crosslinking retarder neutralizing agent present in said slurry in an amount sufficient to crosslink said crosslinkable material and to neutralize said set retarders after placement of said slurry in said zone, said crosslinking-retarder neutralizing agent being selected from the group consisting of alkalnolamine titanium chelates and mixtures of chelates represented by the formulae:
- ##STR5## wherein R.sub.1 is ethylene or isopropylene;
- pumping said cement slurry into said zone by way of said wellbore;
- and
- allowing said cement slurry to set therein.
In a method of cementing a liner in a wellbore using a set retarded aqueous hydraulic cement slurry wherein the cement slurry is subjected to a temperature differential after placement up to about 50.degree. F., the improvement comprising adding to the cement slurry to enhance and make uniform the compressive strength development thereof after placement, an effective amount of a delayed retarder neutralizer selected from the group consisting of alkanolamine titanium chelates and mixtures of such chelates represented by the formulae:
- ##STR6## where R.sub.1 is ethylene or isopropylene.
A method of cementing a subterranean zone penetrated by a well bore comprising:
- providing a set retarded aqueous hydraulic cement slurry;
- admixing with said cement slurry to enhance the compressive strength development thereof after placement, an effective amount of a delayed retarder neutralizer selected from the group consisting of:
- a triethanolamine titanium chelate represented by one of the formula:
- ##STR7## wherein R is independently an alkyl or aryl group, ##STR8## wherein R.sub.1 is independently OC.sub.3 H.sub.7, OH or a halogen atom, and
- partially polymerized chelates produced from said triethanolamine chelates,
- and placing said cement slurry across said zone or zones by way of said well bore and allowing said cement slurry to set into a hard mass therein having enhanced compressive strength.
A method of cementing a subterranean zone penetrated by a well bore comprising:
- providing a set retarded aqueous hydraulic cement slurry;
- admixing with said cement slurry to enhance the compressive strength development thereof after placement, an effective amount of a delayed retarder neutralizer selected from the group consisting of:
- a titanium chelate represented by one of the formula:
- ##STR9## wherein R.sub.1 is independently hydrogen, an alkyl group, or a hydroxyalkyl group,
- R.sub.2 is independently ethylene, trimethylene or isopropylene, and
- R.sub.3 is independently an alkyl or aryl group, ##STR10## wherein R.sub.1 is independently hydrogen, an alkyl group or a hydroxyalkyl group,
- R.sub.2 is independently ethylene, trimethylene or isopropylene, and
- R.sub.4 is independently OC.sub.3 H.sub.7, OH or a halogen atom;
- and placing said cement slurry across the zone or zones by way of said well bore and allowing said cement slurry to set into a hard mass therein having enhanced compressive strength.
A method of cementing a subterranean zone penetrated by a well bore comprising:
- providing a set retarded aqueous hydraulic cement slurry;
- admixing with said cement slurry to enhance the compressive strength development thereof after placement, an effective amount of a delayed retarder neutralizer selected from the group consisting of:
- a triethanolamine titanium chelate represented by the formula:
- ##STR11## wherein R is independently an oxyalkyl group, an oxyaryl group, OH or a halogen,
- R.sub.3 is independently ethylene, trimethylene or isopropylene
- R.sub.4 and R.sub.5 are independently hydrogen, an alkyl group, a hydroxyalkyl group or an aminoalkyl group,
- R.sub.6 is an oxyalkyl group, and R.sub.7 is independently hydrogen, an alkyl group, a hydroxyalkyl group or an aminoalkyl group,
- R.sub.7 is independently hydrogen, alkyl, hydroxyalkyl or an aminoalkyl group;
- and placing said cement slurry across the zone or zones by way of said well bore and allowing said cement slurry to set into a hard mass therein having enhanced compressive strength.
A method of cementing comprising:
- providing a set retarded aqueous hydraulic cement slurry;
- admixing with said cement slurry to enhance compressive strength development thereof after placement, an effective amount of a delayed retarder neutralizer selected from the group consisting of alkanolamine titanium chelates and mixtures of such chelates represented by the formulae:
- ##STR12## where R.sub.1 is ethylene or isopropylene;
- placing said cement slurry in a desired location and allowing said cement slurry to set into a hard mass having enhanced compressive strength.
Dependencies are inferred from the claim text.