USE OF AN ACID SOLUBLE OR DEGRADABLE SOLID PARTICULATE AND AN ACID LIBERATING OR ACID GENERATING COMPOSITE IN THE STIMULATION OF A SUBTERRANEAN FORMATION

• US 20150330197A1
• Filed: 05/15/2015
• Published: 11/19/2015
• Est. Priority Date: 05/19/2014
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Brannon, Harold Dean, Gupta, D.V. Satyanarayana, Bell, Charles Elmer, Szymzak, Stephen Jan
• Granted Patent: US 10,287,865 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C09K 2208/08 Fiber-containing well treatment fluids
• CPC Class Codes: C09K 8/516 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: C09K 8/60 Compositions for stimulating production by acting on the underground formation
• CPC Class Codes: C09K 8/70 characterised by their form or by the form of their components, e.g. foams
• CPC Class Codes: C09K 8/72 Eroding chemicals, e.g. acids
• CPC Class Codes: C09K 8/92 characterised by their form or by the form of their components, e.g. encapsulated material C09K8/70 takes precedence
• CPC Class Codes: E21B 43/16 Enhanced recovery methods for obtaining hydrocarbons
• CPC Class Codes: E21B 43/25 Methods for stimulating production by vibrating earth formations E21B43/003

Abstract

The flow of a stimulation fluid may be diverted from a high permeability zone to a low permeability portion of a subterranean formation by use of an acid soluble or acid degradable solid particulate and a composite of an acid or an acid generating compound adsorbed onto a water-insoluble adsorbent. Conductive flow of hydrocarbons from an occluded fracture may be resumed by release of the acid from the adsorbent or the acid generating compound.

Claims

1. A method of stimulating a subterranean formation penetrated by a well comprising:

(a) pumping into the well (i) an acid soluble or acid degradable solid particulate and (ii) a composite comprising an acid or an acid generating compound adsorbed onto a water-insoluble adsorbent;

(b) blocking permeability in a first zone within the formation with the acid soluble or acid degradable solid particulate;

(c) pumping a stimulation fluid into the well;

(d) diverting the flow of the stimulation fluid to a second zone within the formation, wherein the first zone has higher permeability than the second zone; and

(e) solubilizing or degrading the acid soluble or acid degradable solid particulate by releasing or generating acid from the water-insoluble adsorbent.

2. The method of claim 1, wherein the acid soluble or acid degradable solid particulate is solubilized or degraded in step (e) at a pH of 5.0 or greater.

3. The method of claim 1, wherein the acid soluble or acid degradable solid particulate is a sphere, needle, fiber or a combination thereof.

4. The method of claim 1, wherein the acid soluble or acid degradable solid particulate is alumina, calcium carbonate, benzoic acid, a mineral fiber, sand or a mixture thereof.

5. The method of claim 4, wherein the acid soluble or acid degradable solid particulate is a mineral fiber and further wherein the mineral fiber is mineral wool.

6. The method of claim 1, wherein the acid adsorbed onto the water-insoluble adsorbent is selected from the group consisting of citric acid, phosphonic acid, sulfamic acid, adipic acid, formic acid, phosphoric acid, hydrochloric acid, acetic acid and toluenesulfonic acid, a carboxylic acid and mixtures thereof.

7. The method of claim 1, wherein the acid generating compound is a carboxylic acid ester, an acid anhydride or a lactone.

8. The method of claim 1, wherein the water-insoluble adsorbent is selected from the group consisting of activated carbon, silica particulate, precipitated silica, zeolite, diatomaceous earth, ground walnut shells, fuller'"'"'s earth and organic synthetic high molecular weight water-insoluble adsorbents.

9. The method of claim 1, wherein the composite is pumped into the well in a well treatment fluid and further wherein the amount of composite in the well treatment fluid does not exceed 10 vol. percent.

10. The method of claim 1, wherein the temperature within the well is greater than 250°

F.

11. The method of claim 1, wherein the subterranean formation is a low permeability reservoir.

12. The method of claim 11, wherein the low permeability reservoir is shale.

13. The method of claim 1, wherein the acid soluble or acid degradable solid particulate and the composite are pumped into the well in stages and further wherein the first stage pumped into the well comprises the acid soluble or acid degradable solid particulate and the second stage comprises the composite.

14. The method of claim 13, wherein subsequent to the second stage at least one additional stage is pumped into the well wherein the at least one additional stage comprises an acid soluble or acid degradable solid particulate or a composite or a mixture thereof.

15. The method of any of claim 1, wherein the acid soluble or acid degradable solid particulate and the composite are pumped into the well in stages and further wherein the first stage pumped into the well comprises the composite and the second stage comprises the acid soluble or acid degradable solid particulate.

16. The method of claim 15, wherein subsequent to the second stage at least one additional stage is pumped into the well wherein the at least one additional stage comprises a composite or the acid soluble or acid degradable solid particulate or a mixture thereof.

17. The method of claim 1, wherein wherein the acid soluble or acid degradable solid particulate and the composite are pumped into the well in stages and further wherein the first stage and the second stage pumped into the well comprise the acid soluble or acid degradable solid particulate.

18. The method of claim 17, wherein subsequent to the second stage at least one additional stage is pumped into the well wherein the at least one additional stage comprises the acid soluble or acid degradable solid particulate or the composite or a mixture thereof.

19. The method of claim 1, wherein the acid soluble or acid degradable solid particulate and the composite are pumped into the well in stages and further wherein the first stage pumped into the well comprises the acid soluble or acid degradable solid particulate and the composite and the second stage comprises the acid soluble or acid degradable solid particulate.

20. The method of claim 19, wherein subsequent to the second stage at least one additional stage is pumped into the well wherein the at least one additional stage comprises the acid soluble or acid degradable solid particulate or the composite or a mixture thereof.

21. A method of stimulating a subterranean formation penetrated by a well comprising:

(a) pumping into the well (i) an acid soluble or acid degradable solid particulate and (ii) a composite comprising an acid or an acid generating compound adsorbed onto a water-insoluble adsorbent;

(b) blocking at least a portion of the subterranean formation with the acid soluble or acid degradable solid particulate;

(c) pumping a stimulation fluid into the well;

(d) diverting the flow of the stimulation fluid from the blocked portion of the subterranean formation to another portion of the formation, wherein the permeability of the subterranean formation blocked by the acid soluble or acid degradable solid particulate is greater than the permeability of the another portion of the formation; and

(e) solubilizing or degrading the solid particulate by releasing or generating acid from the water-insoluble adsorbent.

22. A method of increasing the stimulated rock volume of a shale formation comprising:

(a) pumping into a well which penetrates the shale formation an acid soluble or acid degradable solid particulate and a composite comprising an acid or an acid generating compound adsorbed onto a water-insoluble adsorbent wherein;

(i) the acid soluble or acid degradable solid particulate is alumina, calcium carbonate, benzoic acid, mineral fiber, sand or a mixture thereof;

(ii) the acid is citric acid, phosphonic acid, sulfamic acid, adipic acid, formic acid, phosphoric acid, hydrochloric acid, acetic acid or toluenesulfonic acid or a mixture thereof;

(iii) the acid generating compound is a carboxylic acid ester, an acid anhydride or a lactone or a mixture thereof; and

(iv) the water-insoluble adsorbent is activated carbon, silica particulate, precipitated silica, zeolite, diatomaceous earth, ground walnut shells, fuller'"'"'s earth or an organic synthetic polymer or a mixture thereof;

(b) blocking at least a portion of the shale formation with the acid soluble or acid degradable solid particulate;

(c) pumping a stimulation fluid into the well;

(d) diverting the flow of the stimulation fluid from the blocked portion of the subterranean formation to another portion of the formation, wherein the permeability of the subterranean formation blocked by the acid soluble or acid degradable solid particulate is greater than the permeability of the another portion of the formation; and

(e) solubilizing or degrading the solid particulate by releasing the acid from the water-insoluble adsorbent.

23. The method of claim 22, wherein the temperature within the well is greater than 250°

F.