Composites for controlled release of well treatment agents

Patent metadata

Field	Value
Publication number	US-9574130-B2
Application number	US-201514704739-A
Country	US
Kind code	B2
Filing date	May 5, 2015
Priority date	Apr 26, 2011
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

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.

First claim

What is claimed is:

1. A method of treating a subterranean formation penetrated by a well which comprises pumping into the well a fluid having 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 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 m 2 /g to about 10 m 2 /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 g/cc.

2. The method of claim 1 , wherein the metal oxide has been calcined at temperatures greater than or equal to 1200° C.

3. The method of claim 1 , wherein the porous metal oxide is alumina.

4. The method of claim 1 , wherein the well treatment agent is water soluble.

5. The method of claim 1 , wherein the well treatment agent is hydrocarbon soluble.

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

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

8. The method of claim 1 , further comprising introducing well treatment agent into the well after at least a portion of the well treatment agent on the composite has been depleted in order to recharge or reactivate the calcined porous metal oxide of the composite.

9. The method of claim 1 , wherein the subterranean formation is stimulated by pumping the well treatment composite into the well.

10. The method of claim 1 , wherein the formation is subjected to hydraulic fracturing by pumping a fluid containing the well treatment composite into the well at a pressure sufficient to initiate or enlarge a fracture.

11. The method of claim 1 , wherein the treatment of the formation is a sand control operation.

12. The method of claim 10 , wherein the well treatment composite is a proppant and further 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.

13. The method of claim 1 , wherein the crush strength of the well treatment composite containing 10% by weight of well treatment agent at 10,000 psi is substantially the same as the crush strength of the porous metal oxide without the well treatment agent.

14. A method of inhibiting or controlling the rate of release of a well treatment agent in a subterranean formation or in a well by introducing into the formation or well 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 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 m 2 /g to about 10 m 2 /g; (h) 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 gee and wherein the composite has a lifetime, from a single treatment, of at least six months.

15. The method of claim 14 , wherein the porous metal oxide is alumina.

16. The method of claim 14 , wherein the well treatment agent is selected from the group consisting of scale inhibitors, corrosion inhibitors, paraffin inhibitors, salt formation inhibitors, asphaltene dispersants and mixtures thereof.

17. The method of claim 14 , further comprising introducing well treatment agent into the well after at least a portion of the well treatment agent on the composite has been depleted in order to recharge or reactivate the calcined porous metal oxide of the composite.

18. A method of treating a subterranean formation penetrated by a well which comprise pumping into the well a fluid comprising a water soluble or hydrocarbon soluble 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 surface of the calcined porous metal oxide or absorbed into the interstitial spaces of the calcined porous metal oxide 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 forrmation.

19. The method of claim 18 , wherein the porous metal oxide is alumina.

20. The method of claim 18 , wherein at least one of the following conditions apply:
a. the surface area of the calcined porous metal oxide is between from about 1 m 2 /g to about 10 m 2 /g;
b. the diameter of the calcined porous metal oxide is between from about 0.1 to 3 mm; and
c. the pore volume of the calcined porous metal oxide is between from about to about 0.10 cc/g;
d. the bulk density of the composite is between from about 75 to about 150 lb/ft 3 ; or
e. the specific gravity of the well treatment composite is less than or equal to 3.75 g/cc.

Assignees

• Baker Hughes Inc

Inventors

• Gupta D V Satyanarayana

Classifications

• C09K8/80 Primary

  Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open · CPC title

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• C09K8/70

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

• C09K8/54

  Compositions for in situ inhibition of corrosion in boreholes or wells · CPC title

• C09K2208/32

  Anticorrosion additives · CPC title