Continuous obstruction monitor for well logging tools

Patent · Tue Jan 13 04:00:00 EST 1987

OSTI ID:7187545

Thomas, R R

This patent describes an apparatus for continuously monitoring a borehole for obstruction during well logging, comprising an elongate tubular outer housing having means at the upper end for connection to a drill string, a movable inner member slidably supported inside the outer housing, the inner member having means for connection to support a well logging instrument, a releasable means retaining the inner member initially in the lower portion of the housing and to release the inner member upon a predetermined upward force thereon, the outer housing and inner member having relative movement upon contact of the logging instrument with an obstruction within the borehole with sufficient force to release the inner member from the releasable means thereby causing displacement of a column of drilling fluid within the housing and the drill string for detection at the earth surface, and means movable in response to the drilling fluid displacement and having a portion visible at the earth surface to indicate an obstruction. A method is described of continuously monitoring for obstructions within an earth borehole filled with a drilling fluid while passing a well logging instrument therethrough by a drill string comprising: installing an elongate tubular outer housing member to the lower end of a drill string to be transported thereby, the outer housing have a variable volume greater than the volume of an equal length of the drill string transporting it, and enclosing and releasably retaining a movable inner member in the housing and connecting the lower end of the inner member to the upper portion of a well logging instrument. The inner member is releasable to move relative to the outer housing upon the logging instrument contacting an obstruction in the borehole.

• Assignee: NOV; EDB-87-043346; NOV-87-044103
• Patent Number(s): US 4635718
• OSTI ID: 7187545
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
BOREHOLES
CAVITIES
DRILL PIPES
DRILLING EQUIPMENT
DRILLING FLUIDS
EQUIPMENT
FLOW BLOCKAGE
FLUIDS
HOISTING
LEVEL INDICATORS
MATERIALS HANDLING
MEASURING INSTRUMENTS
MONITORING
NATURAL GAS WELLS
OIL WELLS
PIPES
WELL LOGGING
WELL LOGGING EQUIPMENT
WELLS