Means and method for facilitating measurements while coring

Patent · Tue Jan 08 04:00:00 EST 1985

OSTI ID:5755862

Campbell, F L; Barnum, D C; Corea, W C

In accordance with the present invention, rotation of the inner barrel relative of the axis of symmetry of the core barrel (indicative of core twist off or core sand erosion during coring operations) is detected by a novel sensor combination comprising a Hall-effect device imbedded in a support sleeve of a custom safety sub attached to the outer core barrel adjacent to a signature magnet fitted to the inner barrel. During coring, circumferential passage of the Hall-effect device adjacent to thesignature magnet (during rotation of the outer core barrel to generate a core), produces a series of signals of constant repetition rate. But with the occuence of rotation of the inner core barrel irregular repetition rates are produced at uphole indicating equipment connected to the Hall-effect device through conventional downhole telemetering and power generating equipment. Result: sticking and jamming of the core can be immediately detected and uphole parameters modified to ease unsafe conditions.

• Assignee: Chevron Research Co.
• Patent Number(s): US 4492275
• OSTI ID: 5755862
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420206* -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
CONTROL
CORING EQUIPMENT
DRILL CORES
DRILLING EQUIPMENT
EQUIPMENT
MWD SYSTEMS
PROCESS CONTROL
WELLS