Composites for controlled release of well treatment agents

• US 9,029,300 B2
• Filed: 04/26/2011
• Issued: 05/12/2015
• Est. Priority Date: 04/26/2011
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Gupta, D. V. Satyanarayana
• Primary Examiner(s): Figueroa, John J
• Application Number:
  US13/094,186
• Publication Number:
  US 20120273197A1
• Time in Patent Office: 1,477 Days
• Field of Search: None
• US Class Current: 507/269
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 38/0045 by a process involving the formation of a sol or a gel, e.g. sol-gel or precipitation processes
• CPC Class Codes: C04B 38/009 Porous or hollow ceramic granular materials, e.g. microballoons C04B18/027, C04B20/002 take precedence
• CPC Class Codes: C04B 38/0675 Vegetable refuse; Cellulosic materials, e.g. wood chips, cork, peat, paper
• CPC Class Codes: C04B 38/068 Carbonaceous materials, e.g. coal, carbon, graphite, hydrocarbons
• CPC Class Codes: C04B 40/0641 Mechanical separation of ingredients, e.g. accelerator in breakable microcapsules
• CPC Class Codes: C09K 8/536 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: C09K 8/54 Compositions for in situ inhibition of corrosion in boreholes or wells
• CPC Class Codes: C09K 8/80 Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open
• CPC Class Codes: C09K 8/805 Coated proppants
• CPC Class Codes: E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
• CPC Class Codes: E21B 43/26 by forming crevices or fractures
• CPC Class Codes: E21B 43/267 reinforcing fractures by propping

Abstract

A well treatment composite which allows for the slow release of one or more well treatment agents into a subterranean formation and/or a wellbore penetrating the formation has a nano-sized calcined porous substrate (adsorbent) of high surface area onto which is applied the well treatment agent. The composites are suitable for use in such well treatment operations as hydraulic fracturing and sand control.

Claims

1. A well treatment composite comprising a well treatment agent and calcined porous metal oxide wherein the porosity and permeability of the calcined porous metal oxide is such that the well treatment agent is adsorbed onto the calcined porous metal oxide or absorbed into the interstitial spaces of the porous metal oxide and further wherein:

(a) the surface area of the calcined porous metal oxide is between from about 1 m²/g to about 10 m²/g;

(b) the diameter of the calcined porous metal oxide is between from about 0.1 to about 3 mm; and

(c) the pore volume of the calcined porous metal oxide is between from about 0.01 to about 0.10 cc/g.

2. The well treatment composite of claim 1, wherein the composite contains between from about 1 to about 50 weight percent of the well treatment agent.

3. The well treatment composite of claim 1, wherein the porous metal oxide constitutes an adsorbent for the well treatment agent and wherein the adsorbent further contains silica.

4. The well treatment composite of claim 1, wherein the well treatment agent is selected from the group consisting of scale inhibitors, corrosion inhibitors, paraffin inhibitors, salt inhibitors, gas hydrate inhibitors, asphaltene inhibitors, oxygen scavengers, biocides, foaming agent, emulsion breakers and surfactants and mixtures thereof.

5. The method of claim 4, wherein the well treatment agent is a scale inhibitor, corrosion inhibitor, paraffin inhibitor, salt inhibitor, gas hydrate inhibitor, asphaltene inhibitor or mixture thereof.

6. The well treatment composite of claim 5, wherein the calcined porous metal oxide is alumina.

7. The well treatment composite of claim 1, wherein the porous metal oxide is alumina.

8. The well treatment composite of claim 7, wherein the calcined porous alumina is alpha/delta theta alumina or alpha alumina.

9. The well treatment composite of claim 1, wherein the well treatment agent is water soluble.

10. The well treatment composite of claim 1, wherein the well treatment agent is hydrocarbon soluble.

11. A proppant comprising the well treatment composite of claim 1, wherein no greater than 15% of the proppant is crushed at closure stresses of 10,000 psi when the composite contains 10 weight percent of well treatment agent.

12. A well treatment composition comprising the well treatment composite of claim 1 and at least one proppant, wherein the well treatment composite contains between from about 1 to about 50 weight percent of the well treatment agent.

13. The well treatment composition of claim 12, wherein the porous metal oxide of the well treatment composite is alumina.

14. A well treatment composite for introduction into a subterranean formation, the well treatment composite comprising a water soluble or hydrocarbon soluble well treatment agent and calcined porous alumina wherein the porosity and permeability of the calcined porous alumina is such that the well treatment agent is adsorbed onto the surface of the calcined porous alumina or absorbed into the interstitial spaces of the calcined porous alumina and further wherein the well treatment composite contains between from about 1 to about 50 weight percent of the well treatment agent which is capable of being desorbed at a generally constant rate over an extended period of time in the formation fluid contained in the subterranean formation.

15. The well treatment composite of claim 14, wherein the alumina has been calcined at temperatures greater than or equal to 1200°

C.

16. The well treatment composite of claim 15, wherein the alumina has been calcined at temperatures greater than or equal to 1400°

C.

17. The well treatment composite of claim 14, wherein. the calcined porous alumina constitutes an adsorbent for the well treatment agent and wherein the adsorbent further contains silica.

18. The well treatment composite of claim 14, wherein:

(a) the surface area of the calcined porous metal oxide is between from about 1 m²/g to about 10 m²/g;

(b) the diameter of the calcined porous metal oxide is between from about 0.1 to 3 mm;

(c) the pore volume of the calcined porous metal oxide is between from about 0.01 to about 0.10 cc/g;

(d) the bulk density of the composite is between from about 75 to about 150 lb/ft³; and

(e) the specific gravity of the well treatment composite is less than or equal to 3.75 g/cc.

19. A well treatment composition comprising the well treatment composite of claim 14 and a proppant.