Method of using high-alumina cements for rheology control of liquid phases

Abstract

Rheological control of liquid phases is provided with a composition comprising a high-alumina cement component a) for controlling the rheology of liquid phases based on a clay component b). Component a) is preferably a calcium aluminate cement and component b) is preferably a clay of the smectite variety. The compositions comprise at least 20% by weight representative of the calcium aluminate cement and is preferably used for rheology control of water- or oil-based systems.

Description

Claims

1. A method comprising controlling rheology of a liquid phase comprising a clay component b) by adding a sufficient amount of a high-alumina cement component a) to the liquid phase to control the rheology of the liquid phase.

2. The method according to claim 1, wherein the clay component b) comprises smectites, bentonites, montmorillonites, beidellites, hectorites, saponites, sauconites, vermiculites, illites, kaolinites, chlorites, attapulgites, sepiolites, palygorskites, halloysites and Fuller's earths and preferably clays of the smectite type, in particular hectorite, and particularly preferably montmorillonites and bentonites.

3. The method according to claim 1, wherein the clay component comprises an additive selected from the group consisting of a partially hydrolysed polyacrylamide (PHPA) as a “bentonite extender”, an additive that is chemically modified, or is a clay component which has been rendered hydrophobic for use in oil-based drilling fluids.

4. The method according to claim 1, wherein component a) is selected from the group consisting of a calcium monoaluminate cement, a calcium dialuminate cement, a dodecacalcium heptaaluminate cement and a calcium hexaaluminate cement or a hydration product thereof.

5. The method according to claim 1, wherein component a) comprises at least 20% by weight of at least one calcium aluminate cement.

6. The method according to claim 1, wherein the component a) is present in an amount of ≦10% by weight based on the liquid phase.

7. The method according to claim 1, wherein the liquid phase is a water-based system, an oil-based system, an emulsion or an invert emulsion.

8. The method according to claim 1, wherein the liquid phase comprises drilling fluids further comprising at least one further additive for controlling the rheology, for filtrate reduction, for controlling the density, the cooling and lubrication of the drill bit, for stabilizing the well wall or for chemically stabilizing the drilling fluid.

9. The method according to claim 1, wherein the amount of component a) is sufficient to provide for the shear-thinning or thixotropic thickening of the liquid phase.

10. The method according to claim 1, wherein component a) comprises at least 30% by weight of at least one calcium aluminate cement.

11. The method according to claim 1, wherein component a) comprises at least 50% by weight of at least one calcium aluminate cement.

12. The method according to claim 1, wherein component a) comprises at least 90% by weight of at least one calcium aluminate cement.

13. The method of claim 6, wherein component a) is present in an amount of less than or equal to 5% by weight based on the liquid phase.

14. The method of claim 13, wherein component a) is present in an amount of from 0.1 to 1.0% by weight of the liquid phase.

15. The method according to claim 1, wherein component a) comprises from 20% to 90% by weight of said at least one calcium aluminate cement.

16. The method of claim 15, wherein the high alumina cement comprises from 30 to 90% by weight alumina.

17. The method of claim 16, wherein the high alumina cement comprises from 30 to 60% by weight alumina.

18. The method of claim 1, wherein component a) is selected from the group consisting of a calcium monoaluminate cement, a calcium dialuminate cement, a dodecacalcium heptaalumiante cement and a calcium hexaalumiante cement.