Wire line core drilling apparatus

• US 5,020,612 A
• Filed: 02/22/1990
• Issued: 06/04/1991
• Est. Priority Date: 02/22/1989
• Status: Expired due to Term

• Current Assignee: Longyear TM Incorporated (Boart Longyear Limited)
• Original Assignee: Boast International Limited
• Inventors: Williams, David Stanley
• Primary Examiner(s): Dang, Hoang C.
• Application Number:
  US07/483,024
• Time in Patent Office: 467 Days
• Field of Search: 175/243, 175/246, 175/247, 175/234, 175/236, 175/317, 175/58, 175/324, 175/257, 175/403
• US Class Current: 175/234
• CPC Class Codes: E21B 21/10 Valve arrangements in drilling-fluid circulation systems
• CPC Class Codes: E21B 23/02 for locking the tools or the like in landing nipples or in recesses between adjacent sections of tubing E21B23/03 - E21B23/06 take precedence
• CPC Class Codes: E21B 25/02 the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe

Abstract

A wire line core barrel inner tube assembly has a latch body with a miximum diameter portion providing a shoulder seatable on a drill string landing ring and a fluid bypass channel extending through the maximum diameter portion and a valving assembly. The valving assembly includes a resilient valve seat in the bypass channel and a ball seatable on the valve seat to block fluid flow in a downward direction through the channel, movable upwardly off the valve seat from the seated position to permit fluid flow through the seat in the opposite direction and movable through the seat to a channel open condition after a preselected fluid pressure has been exerted on the ball in a direction to move the ball from the ball seated position and through the valve seat.

Claims

1. A core barrel inner tube assembly for a wire line core drilling apparatus, comprising:

a body having a valve chamber;

seating means comprising a landing shoulder on the body for seating upon a landing ring carried by a core barrel outer tube of the wire line core drilling apparatus when the core barrel inner tube assembly is correctly landed in the core barrel outer tube;

an inlet port and an outlet port leading from an exterior portion of the body to the valve chamber on opposite sides of the landing shoulder so as to establish a bypass passage which bypasses the landing shoulder and through which drilling liquid is forced to flow when the landing shoulder is correctly seated upon the landing ring;

a deformable, annular valve seat disposed within the bypass passage;

valve closing means made of harder material than the valve seat for seating on the valve seat to prevent drilling liquid from flowing through the bypass passage until pressure of the drilling liquid is sufficient to force the valve closing means through the valve seat; and

pressure monitoring and recording means for monitoring an increase in the pressure of the drilling liquid and for recording a pulse in the pressure indicating that correct landing has taken place;

wherein said valve seat comprises a central region having a diameter less than that of the valve closing means, and tapered end regions which facilitate forcing of the valve closing means through the valve seat from either end.

2. A core barrel inner tube assembly as claimed in claim 1, wherein the body is a latch body carrying spring loaded latches adapted to engage the core barrel outer tube when the landing shoulder is correctly seated on the landing ring.