Filtrate control agents in solid form

Patent metadata

Field	Value
Publication number	US-10150702-B2
Application number	US-201314373689-A
Country	US
Kind code	B2
Filing date	Jan 25, 2013
Priority date	Jan 25, 2012
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

The present invention relates to a process for preparing control agents for applications in the petroleum field, where a polymer bearing —OH, amine and/or amide functions, which is in the form of a divided solid, is reacted with at least one crosslinking agent bearing at least two —R groups capable of reacting with the —OH, amine or amide groups, under conditions where said polymer remains in solid form and where said crosslinking agent is at least partly in vapor form, The invention also relates to the control agents obtained in solid form according to this process, and also to the mixtures of these solid agents with other additives, which can be used in particular for the preparation of cement grout for oil extraction.

First claim

The invention claimed is:

1. A process for the preparation of a fluid loss control agent, in the solid form, comprising a stage (E1) where a polymer carrying several —OH and/or amine and/or amide functional groups, in the form of a divided solid wherein said polymer is in the form of solid objects having particle size of less than 1 cm, is reacted with at least one crosslinking agent carrying at least two —R groups capable of reacting with the —OH, amine or amide groups of said polymer under the conditions of said stage (E1) in order to form a covalent bond between the polymer and the crosslinking agent, wherein said stage (E1) being carried out under temperature and pressure conditions where said polymer remains in the solid form and where said crosslinking agent is at least partially in the vapor form, whereby a crosslinking of the polymer within the particles of the divided solid is obtained;
wherein said polymer is in the form of isotropic objects with a mean particle size of between 1 micron and 100 microns or in the form of anisotropic objects in which the smallest dimension is between 1 micron and 250 microns.

2. The process as claimed in claim 1 , the polymer employed in said stage (E1) is a polyvinyl alcohol (PVA).

3. The process as claimed in claim 1 , wherein the at least two —R groups present on the crosslinking agent and suitable for forming covalent bonds by reaction with the —OH and/or amide groups of the polymer are aldehyde —CHO groups.

4. The process as claimed in claim 3 , wherein the crosslinking agent is glutaraldehyde.

5. The process as claimed in claim 1 , wherein the crosslinking agent/polymer ratio by weight is less than 2%.

6. The process as claimed in claim 1 , wherein said stage (E1) suitable for activating the reaction between the —R groups of the crosslinking agent and the —OH or amide groups of the polymer is carried out in the presence of a catalyst.

7. The process as claimed in claim 1 , wherein said stage (E1) of the process of the invention is carried out by first producing a blend of the polymer in the form of a divided solid with a second divided solid comprising the crosslinking agent and by then holding this blend under the temperature and pressure conditions where the polymer remains in the solid form and where said crosslinking agent is at least partially in the vapor form, said second divided solid being:
a solid comprising the crosslinking agent in the solid form; or
a solid comprising the crosslinking agent in the liquid form deposited on a solid support.

8. The process as claimed in claim 1 , wherein said stage (E1) is carried out by injecting the crosslinking agent in the liquid form within a confined reactor within which temperature and pressure conditions prevail where said polymer remains in the solid form and where said crosslinking agent is at least partially in the vapor form, whereby the crosslinking agent, introduced in the liquid form, vaporizes within the reactor.

9. The process as claimed in claim 1 , wherein said stage (E1) is carried out at a temperature of less than 150° C.

10. The process as claimed in claim 1 , which additionally comprises a stage (E2) of recovery of the solid obtained on conclusion of said stage (E1).

11. The process as claimed in claim 1 , wherein said stage (E1) is followed by a stage (E3), wherein the solid obtained on conclusion of said stage (E1) is blended with other solid compounds suitable for forming a fluid of use in the field of oil extraction.

12. A fluid loss control agent in the solid form capable of being obtained according to said stage (E1) of the process of claim 1 .

13. A method for improving the gas migration and/or fluid loss control properties of an oil cement grout, of a drilling fluid for oil application or of a fracturing fluid for oil application, said method comprising a step of using said control agent as claimed in claim 12 .

14. A solid preblend for the manufacture of a fluid of use in the field of oil extraction capable of being obtained according to said stage (E3) of claim 11 , comprising:
a fluid loss control agent in the solid form capable of being obtained according to said stage (E1) of the process of claim 1 ; and
other solid compounds suitable for forming a fluid of use in the field of oil extraction, in particular an oil cement grout, a drilling fluid for oil application or a fracturing fluid for oil application.

15. The process as claimed in claim 6 , wherein said catalyst is being employed in the vapor form during said stage (E1).

16. The process as claimed in claim 9 , wherein said stage (E1) is carried out at a temperature between 100 and 150° C.

Assignees

• Rhodia Operations

Inventors

• Cadix Arnaud

Classifications

• C08J2329/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08K5/0025

  Crosslinking or vulcanising agents; including accelerators · CPC title

• C09K8/70

  characterised by their form or by the form of their components, e.g. foams · CPC title

• C08B37/0033

  Xanthan, i.e. D-glucose, D-mannose and D-glucuronic acid units, saubstituted with acetate and pyruvate, with a main chain of (beta-1,4)-D-glucose units; Derivatives thereof · CPC title

• C04B24/2623

  Polyvinylalcohols; Polyvinylacetates · CPC title