Patent · US Expired

Drill pipe inside blowout preventer

US4694855A · kind A · utility

11Cited by
7References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 23, 1986
Grant dateSep 22, 1987
Priority date
Expiry dateMay 23, 2006

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/791
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

An inside blowout preventer for use in an earth boring drill string has features to reduce erosion. The blowout preventer has a valve body for connection into the drill string with a longitudinal passage extending through the body. The ball seat is located in the longitudinal passage. A ball storage location is located below the seat, and offset from the longitudinal passage. A ball is carried in the storage location during downward flow, and moves into the longitudinal passage to seat against the seat if the upward flow is sufficient. The storage location is located in an area of the longitudinal passage which has a much larger flow area than through the seat. The downward flow impinges on a portion of the ball. A communication passage extends from the storage location downward to a reduced diameter section of the longitudinal passage.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.