Drilling fluid processing

Patent metadata

Field	Value
Publication number	US-9518435-B2
Application number	US-201214240604-A
Country	US
Kind code	B2
Filing date	Oct 1, 2012
Priority date	Sep 30, 2011
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A method of processing a return oil-based drilling fluid includes centrifuging a primarily fluids phase at a first speed and separating the primarily fluids phase into a first effluent and a first residual, centrifuging the first effluent at a second speed and separating the first effluent into a second effluent and a second residual, and centrifuging the second effluent at a third speed and separating the second effluent into a third effluent and a third residual. A surfactant, a polymer, combinations of surfactant(s) and polymer(s) and/or a wash water may be added to one or more of the return oil-based drilling fluid, the primarily fluids phase, the primarily solids phase, the first effluent, the second effluent, and the third effluent.

First claim

What is claimed:

1. A method of processing a return oil-based drilling fluid comprising:
mixing a volume of a base oil fluid to the return oil-based drilling fluid to break an emulsion of the return oil-based drilling fluid and form a diluted return oil-based drilling fluid, wherein the ratio of the volume of base oil fluid added to a volume of the return oil-based drilling fluid is between about 0.1 and 0.4;
separating the diluted return oil-based drilling fluid into a primarily solids phase and a primarily fluids phase;
adding a surfactant to the primarily fluids phase; and
adding a polymer to the primarily fluids phase.

2. The method of claim 1 , further comprising mixing a second volume of the base oil fluid to the primarily fluids phase and separating a separated solids phase and a treated return oil-based fluid from the primarily fluids phase.

3. The method of claim 1 , wherein the separating comprises directing the diluted return oil-based drilling fluid to at least one of a centrifuge, a settling tank, and a coalescer.

4. The method of claim 2 , further comprising returning the treated return oil-based drilling fluid to a drilling fluid system.

5. The method of claim 2 , further comprising returning the treated return oil-based drilling fluid to a mixing tank as the base oil fluid.

6. The method of claim 1 , wherein the polymer is a dry polymer.

7. The method of claim 6 , further comprising hydrating the dry polymer before adding the polymer to the return oil-based drilling fluid by mixing water with the dry polymer.

8. The method of claim 1 , further comprising drying the primarily solids phase to produce a separated solids phase.

9. The method of claim 8 , further comprising disposing of the separated solids phase.

10. The method of claim 1 , further comprising washing the primarily solids phase to form a treated solids phase.

11. The method of claim 10 , further comprising adding a binding agent to the treated solids phase to form a construction material.

12. The method of claim 10 , further comprising disposing of the treated solids phase.

13. The method of claim 10 , wherein the washing comprises adding a wash fluid to the primarily solids phase to form a wash stream.

14. The method of claim 13 , further comprising returning the wash stream to a drilling fluid system.

Assignees

• M-I L L C
• M-I L L C

Inventors

• Fout Gary
• Savoy Michael

Classifications

• E21B21/065 Primary

  Separating solids from drilling fluids · CPC title

• E21B21/066 Primary

  with further treatment of the solids, e.g. for disposal · CPC title

• B01D21/02

  Settling tanks {with single outlets for the separated liquid} · CPC title

• E21B21/062

  by mixing components · CPC title

• C09K8/24

  Polymers · CPC title