Cement spacer system for wellbores, methods of making, and methods of use

Patent metadata

Field	Value
Publication number	US-9951261-B2
Application number	US-201514643117-A
Country	US
Kind code	B2
Filing date	Mar 10, 2015
Priority date	Mar 10, 2015
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A cement spacer fluid for use in a wellbore includes an aqueous cement spacer carrier fluid and a preformed synthetic polymer swellable in the aqueous cement spacer carrier fluid in an amount effective to displace a drilling fluid during a cementing operation. Preferably, the polymer is particulate, and forms a hydrated pack of particles. A method of cementing a wellbore comprising a drilling fluid includes injecting the cement spacer fluid into the wellbore to displace the drilling fluid; injecting a cement slurry into the wellbore subsequent to injecting the cement spacer fluid; and hardening the cement in the slurry to cement the wellbore.

First claim

The invention claimed is:

1. A method of cementing a wellbore comprising a drilling fluid, the method comprising
injecting a cement spacer fluid into the wellbore to displace the drilling fluid;
injecting a cement slurry into the wellbore subsequent to injecting the cement spacer fluid; and
hardening the cement in the slurry to cement the wellbore,
wherein the cement spacer fluid comprises:
an aqueous cement spacer carrier fluid; and
a preformed synthetic polymer swellable in the aqueous cement spacer carrier fluid in an amount effective to displace a drilling fluid during a cementing operation,
wherein the preformed synthetic polymer comprises
a copolymer of (meth)acrylamide with maleic anhydride, vinyl acetate, ethylene oxide, ethylene glycol, acrylonitrile, or a combination comprising at least one of the foregoing;
poly(acrylamide) having crosslinks derived from polyethylene glycol diacrylate;
poly(acrylic acid) having crosslinks derived from a vinyl ester oligomer;
a poly(acrylic acid) partial sodium salt-graft-poly(ethylene glycol); or
a copolymer of acrylic acid and a salt thereof having crosslinks derived from polyethylene glycol diacrylate; and
the preformed synthetic polymer is present in the cement spacer fluid in a concentration of about 10 pounds to about 200 pounds per thousand gallons of aqueous cement spacer carrier fluid.

2. The method of claim 1 , wherein displacing the drilling fluid further comprises displacing a contaminant particulate present in the wellbore.

3. The method of claim 2 , wherein the contaminant particulate comprises a drilling fluid particulate, drilling cutting, a reservoir rock particulate, mudstone particulate, sandstone particulate, carbonate particulate, or a combination comprising at least one of the foregoing.

4. The method of claim 1 , wherein the cement spacer fluid is a first cement spacer fluid, and the method further comprises injecting a second spacer fluid into the well bore after the first spacer fluid and before the cement slurry.

5. The method of claim 1 , wherein the wellbore is a vertical or horizontal wellbore.

6. The method of claim 1 , wherein the wellbore has a bottom hole temperature of about 80° F. to about 350° F.

7. The method of claim 1 , wherein the carrier fluid comprises fresh water, salt water, aqueous acid, aqueous base, or a combination comprising at least one of the foregoing.

8. The method of claim 1 , wherein the preformed synthetic polymer is stable up to about 350° F.

9. The method of claim 1 , wherein the preformed synthetic polymer is present in the form of particles comprising the polymer.

10. The method of claim 1 , wherein the particles are swelled and at least about 50% of the polymer particles have an average largest diameter of about 500 to about 12,000 micrometers.

11. The method of claim 1 , wherein the preformed synthetic polymer is present in the cement spacer fluid in a concentration of about 10 pound to about 100 pounds per thousand gallons of aqueous cement spacer carrier fluid.

12. The method of claim 1 , wherein the preformed synthetic polymer is present in the cement spacer fluid in a concentration of about 30 pound to about 60 pounds per thousand gallons of aqueous cement spacer carrier fluid.

13. The method of claim 1 , further comprising guar, carrageenan, or a combination comprising at least one of the foregoing.

14. The method of claim 1 , wherein the preformed synthetic polymer is present in the form of a hydrated pack of swelled polymer particles.

15. The method of claim 1 , wherein the cement spacer fluid is a fluid foam.

16. The method of claim 1 , wherein the cement spacer fluid further comprises a borate, titanate, zirconate, aluminate, chromate crosslinker, or a combination comprising at least one of the foregoing.

Assignees

• Nelson Scott Gregory
• Baker Hughes A Ge Co Llc

Inventors

• Nelson Scott Gregory

Classifications

• C04B24/2664

  of ethylenically unsaturated dicarboxylic acid polymers, e.g. maleic anhydride copolymers · CPC title

• C04B24/2623

  Polyvinylalcohols; Polyvinylacetates · CPC title

• C04B40/0035

  Processes characterised by the absence of a mechanical mixing step, e.g. "no-mix" processes · CPC title

• C04B2103/0043

  Compounds chosen for their specific Moh's hardness · CPC title

• C04B24/2652

  Nitrogen containing polymers, e.g. polyacrylamides, polyacrylonitriles · CPC title