SACRIFICIAL SPACER FOR WELL TOOL INNER SEAL

• US 20160194918A1
• Filed: 09/10/2013
• Published: 07/07/2016
• Est. Priority Date: 09/10/2013
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: WILLIAMS, Mark E.
• Granted Patent: US 10,458,186 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E21B 10/22 characterised by bearing, lubrication or sealing details
• CPC Class Codes: E21B 10/25 characterised by sealing details
• CPC Class Codes: F16J 15/002 comprising at least two sealings in succession F16J15/162, F16J15/40 take precedence
• CPC Class Codes: F16J 15/02 between relatively-stationary surfaces F16J15/46, F16J15/48 take precedence
• CPC Class Codes: F16J 15/162 Special parts or details relating to lubrication or cooling of the sealing itself F16J15/324, F16J15/3404, F16J15/40 take precedence

Abstract

A well tool can include inner and outer seals interposed between components of the well tool, and a circumferential spacer which prevents contact between the inner seal and one of the components which displaces relative to the inner seal. A method of sealing between components of a well tool can include sealingly engaging an outer seal between the components, and disposing an inner seal between the components, including spacing the inner seal away from one of the components, whereby the inner seal sealingly contacts one of the components only after the well tool is disposed in a well. A drill bit can include inner and outer seals interposed between components of the drill bit, and a circumferential spacer which prevents contact between the inner seal and one of the components, the circumferential spacer being positioned upstream of the outer seal relative to a lubricant supply of the drill bit.

Claims

1. A drill bit, comprising:

an outer seal interposed radially between a cone and a journal of the drill bit and sealingly engaged with the journal and cone, an inner seal positioned in a groove formed on either the cone or the journal and not sealingly in contact with the journal and cone; and

a circumferential spacer positioned radially between the inner seal and either the cone or the journal, whichever does not contain the groove in which the inner seal is positioned, the circumferential spacer including a material that radially spaces apart the inner seal from either the cone or the journal, whichever does not contain the groove in which the inner seal is positioned, wherein there is a greater coefficient of friction between the circumferential spacer and the inner seal than between the circumferential spacer and the cone or the journal, whichever does not contain the groove in which the inner seal is positioned.

2. The drill bit of claim 1, wherein the circumferential spacer is positioned upstream of the outer seal relative to a lubricant supply of the drill bit.

3. The drill bit of claim 1, further comprising an equalizing passage which permits fluid communication across the circumferential spacer.

4. The drill bit of claim 3, wherein the equalizing passage is formed in the circumferential spacer.

5. The drill bit of claim 3, wherein the equalizing passage permits fluid communication between a lubricant supply of the drill bit and a space defined between the inner and outer seals.

6. The drill bit of claim 1, wherein the circumferential spacer and the inner seal are separate elements of the drill bit.

7. The drill bit of claim 6, wherein the circumferential spacer is positioned between the outer seal and retaining balls which retain the cone on the journal.

21. The drill bit of claim 1, wherein a portion of the circumferential spacer in contact with the inner seal is textured.

22. The drill bit of claim 21, wherein the portion of the circumferential spacer in contact with the inner seal comprises protrusions and/or recesses.

23. The drill bit of claim 1, wherein a portion of the circumferential spacer in contact with the either the journal or the cone, whichever does not contain the groove in which the inner seal is positioned, is smooth.

24. The drill bit of claim 23, wherein the portion of the circumferential spacer in contact with either the journal or the cone, whichever does not contain the groove in which the inner seal is positioned, comprises poly-tetra-fluoro-ethylene (PTFE) or poly-ether-ether-ketone (PEEK)).

25. The drill bit of claim 1, wherein the circumferential spacer has a rounded side in contact with the inner seal and a flat side in contact with either the journal or the cone, whichever does not contain the groove in which the inner seal is positioned.

26. The drill bit of claim 1, wherein the circumferential spacer comprises a first arm positioned between the inner seal and either the journal or the cone, whichever does not contain the groove in which the inner seal is positioned, and a second arm positioned on a side of the inner seal facing the outer seal.

8. A method of sealing between a journal and a cone of a drill bit, the method comprising:

sealingly engaging an outer seal radially between the journal and the cone;

disposing an inner seal radially between the journal and the cone; and

positioning a circumferential spacer between the inner seal and either the journal or the cone to space the inner seal radially away from either the journal or the cone,

wherein the inner seal sealingly contacts both the journal and the cone only after the drill bit is disposed in a well.

9. The method of claim 8, wherein the inner seal sealingly contacts both the journal and the cone only after fluid communication is permitted across the outer seal.

11. The method of claim 8, wherein the circumferential spacer wears away and thereby permits the inner seal to sealingly contact both the journal and the cone after the drill bit is disposed in the well.

13. The method of claim 8, further comprising lubricant flow across the circumferential spacer to or from a space defined between the inner seal and outer seal via an equalizing passage in the circumferential spacer.

27. The method of claim 8, wherein the inner seal sealingly contacts both the journal and the cone only after the drill bit is used to drill a wellbore.

28. The method of claim 8, wherein the circumferential spacer experiences higher friction between itself and the inner seal than between itself and either the journal or the cone when used to drill a wellbore.

10. (canceled)

12. (canceled)

14-20. -20. (canceled)