Cement oil-based mud spacer formulation

Patent metadata

Field	Value
Publication number	US-9884985-B2
Application number	US-201615365553-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Oct 12, 2011
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

A spacer fluid made of a viscosity thinner, a weighting agent, an antifoaming agent, and a non-ionic surfactant in a base aqueous fluid is disclosed. In some instances, the viscosity thinner is a sulfomethylated tannin, the weighting agent is barium sulfate, the antifoaming agent is a silicone, and the non-ionic surfactant is an ethoxylated alcohol. A method of treating a well bore annulus in preparation of introducing water-based cement slurry into a well bore using the spacer fluid is disclosed. A method of using the spacer fluid to position a first fluid into a well bore annulus of a well bore containing a second fluid is disclosed. A method for fluidly isolating at least a portion of a well bore annulus in a well bore containing an oil-based drilling fluid using water-based cement slurry and the spacer fluid is disclosed.

First claim

What is claimed is:

1. A spacer fluid composition for use between a first fluid and a second fluid, the spacer fluid composition comprising:
a base aqueous fluid comprising fresh water,
a viscosifier comprising a chemically modified tannin,
a weighting agent comprising barite,
an antifoaming agent comprising a silicone-based liquid, and
a non-ionic surfactant comprising an alkoxylated alcohol,
where a measured viscosity of a mixture of the first fluid and the spacer fluid composition at a first ratio of the first fluid to the spacer fluid composition is less than a measured viscosity of a mixture of the second fluid and the first fluid at a second ratio of the second fluid to the first fluid, where the first ratio and second ratio are substantially the same, and where the second fluid comprises an oil-based fluid and the first fluid comprises a water-based cement slurry,
where a measured viscosity of a mixture of the second fluid and the spacer fluid composition at a third ratio of the second fluid to the spacer fluid composition is less than a measured viscosity of a mixture of the second fluid and the first fluid at the second ratio of the second fluid to the first fluid, where the third ratio is substantially the same as the first ratio and the second ratio,
where a measured viscosity of the spacer fluid composition is less than a measured viscosity of the first fluid and a measured viscosity of the second fluid, and where the spacer fluid composition maintains compatibility with both the first fluid and the second fluid during heavy contamination when the volume percent of the spacer fluid composition is about 50% by volume in a mixture comprising the spacer fluid composition, the first fluid at about 25% by volume, and the second fluid at about 25% by volume, and
where the first fluid is operable to mix with the spacer fluid composition up to a volume ratio of about 95:5 first fluid to spacer fluid composition, such that the water-based cement slurry compressive strength upon setting to a solid cement is increased by at least about 25% at about 24 hours compared to the water-based cement slurry alone.

2. The spacer fluid composition of claim 1 where the first fluid and the second fluid are incompatible, and do not readily mix with one another.

3. The spacer fluid composition of claim 1 where the water-based cement slurry is a water-based latex cement slurry.

4. The spacer fluid composition of claim 1 where the spacer fluid composition is operable to produce a 75:25 volume percent mixture of spacer fluid composition to an oil-based drilling mud having a yield point value of no greater than about 49 pounds per 100 square feet.

5. The spacer fluid composition of claim 1 where the chemically modified tannin is a sulfomethylated tannin.

6. The spacer fluid composition of claim 1 where the viscosifier is in a range of from about 5 pounds to about 10 pounds per barrel of base aqueous fluid present in the spacer fluid composition.

7. The spacer fluid composition of claim 1 where the weighting agent is in a range of from about 100 pounds to about 400 pounds per barrel of base aqueous fluid in the spacer fluid composition.

8. The spacer fluid composition of claim 1 where the density of the spacer fluid is in a range of from about 70 to about 120 pounds per cubic foot.

9. The spacer fluid composition of claim 1 where the alkoxylated alcohol is an ethoxylated alcohol.

10. The spacer fluid composition of claim 1 where the antifoaming agent is in a range of from about 0.01 gallons to about 0.2 gallons per barrel of base aqueous fluid in the spacer fluid composition.

11. The spacer fluid composition of claim 1 where the non-ionic surfactant agent is in a range of from about 1.5 gallons to about 2.0 gallons per barrel of base aqueous fluid in the spacer fluid composition.

12. The spacer fluid composition of claim 1 where the non-ionic surfactant further comprises isopropyl alcohol, naphthalene and heavy aromatic petroleum naphtha.

13. The spacer fluid composition of claim 1 , where the water-based cement slurry has a density in a range of from about 101 pounds per cubic foot to about 125 pounds per cubic foot.

14. The spacer fluid composition of claim 1 , where the oil-based fluid has a density in a range of from about 56 pounds per cubic foot to about 81 pounds per cubic foot.

15. The spacer fluid composition of claim 1 , where the chemically modified tannin is at a concentration of about 8.5 pounds per barrel, the barite is at a concentration of about 377 pounds per barrel, the silicone liquid is at a concentration of about 0.1 gallons per barrel, and the alkoxylated alcohol comprises an ethoxylated alcohol at a concentration of about 1.9 pounds per barrel.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al Subhi Mohammad Lafi
• Jennings Scott Steven
• Al Humaidi Ahmad Saleh

Classifications

• C04B2103/40

  Surface-active agents, dispersants · CPC title

• C04B24/023

  Ethers · CPC title

• C04B26/04

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C04B28/04

  Portland cements · CPC title

• C04B2103/50

  Defoamers, air detrainers · CPC title