Seal cup for a wellbore tool and method
A seal cup and method is disclosed that can be used on a wellbore tool. The seal cup includes an external circumferential seal land adjacent the cup lip and an outer surface capable of permitting drainage away from the seal land of fluids, which may seep past the seal land. This acts against pressure invasion in the interfacial contacting region between the seal cup and the structure, for example, a wellbore liner against which it is sealed.
1. A seal cup comprising: a base; an elongate substantially tubular interval extending from the base and ending at a lip; an outer surface extending from the lip to the base; at least one circumferential seal land on the outer surface adjacent the lip of the tubular interval; a circumferential drainage groove on the outer surface adjacent the seal land; and an axial drainage groove extending from the drainage groove toward the base, the circumferential drainage groove and the axial drainage groove being capable, under operational pressure for which the seal cup is to be used, of conducting seepage fluid from adjacent the seal land toward the base to act against pressure invasion about the outer surface.
2. The seal cup of claim 1 wherein the elongate substantially tubular interval has a thickness increasing from the lip to the base.
3. The seal cup of claim 1 wherein the seal cup has an outer diameter along the tubular interval which tapers from the seal land towards the base.
4. The seal cup of claim 1 wherein the seal cup has an outer diameter along the tubular interval and the base, which tapers from the seal land to the base and the diameter at the base is substantially equal to the inner diameter against which the seal cup is to seal.
5. The seal cup of claim 1 including a radiused portion between the lip and the seal land.
6. The seal cup of claim 1 including a wear resistant insert in the outer surface adjacent the seal land.
7. A seal cup for mounting on a wellbore tool to seal the annulus about the tool when used in a wellbore, the seal cup comprising: a base including a portion mountable to the tool; an elongate substantially tubular interval extending from the base and ending at a lip; an outer surface extending from the lip to the base; at least one circumferential seal land on the outer surface adjacent the lip of the tubular interval, the seal land including a diameter selected to allow sealing in the annulus about the tool in the wellbore in which the seal cup and tool are to be used; a circumferential drainage groove on the outer surface adjacent the seal land; and an axial drainage groove extending from the drainage groove to the base, the circumferential drainage groove and the axial drainage groove being capable, under wellbore pressure, of conducting seepage fluid from adjacent the seal land toward the base to act against pressure invasion about the outer surface.
8. The seal cup of claim 7 wherein the elongate substantially tubular interval has a thickness increasing from the lip to the base.
9. The seal cup of claim 7 wherein the seal cup has an outer diameter along the tubular interval which tapers from the seal land towards the base.
10. The seal cup of claim 7 wherein the seal cup has an outer diameter along the tubular interval and the base, which tapers from the seal land to the base and the diameter at the base is substantially equal to the inner diameter against which the seal cup is to seal.
11. The seal cup of claim 7 including a radiused portion between the lip and the seal land.
12. The seal cup of claim 7 including a wear resistant insert in the outer surface adjacent the seal land.