EP 0408667 A4 19910814 - ACOUSTIC DATA TRANSMISSION THROUGH A DRILL STRING
Title (en)
ACOUSTIC DATA TRANSMISSION THROUGH A DRILL STRING
Publication
Application
Priority
US 18432688 A 19880421
Abstract (en)
[origin: WO8910572A1] Acoustical signals are transmitted through a section of drill string (30) by cancelling upward moving acoustical noise and by preconditioning the data in recognition of the comb filter characteristics of the drill string. Spaced sensors (52, 54) provide a delayed signal to summer (46) which is combined with a signal from suitable circuitry (28) and then applied to sensors (42, 44) for transmitting an uphole signal having no downward moving noise.
IPC 1-7
IPC 8 full level
G01V 1/40 (2006.01); E21B 47/16 (2006.01)
CPC (source: EP)
E21B 47/16 (2013.01)
Citation (search report)
- [AD] US 4293936 A 19811006 - COX WILLIAM H, et al
- [AD] US 4562559 A 19851231 - SHARP H EUGENE [US], et al
- See references of WO 8910572A1
Designated contracting state (EPC)
DE FR GB NL
DOCDB simple family (publication)
WO 8910572 A1 19891102; DE 68912584 D1 19940303; EP 0408667 A1 19910123; EP 0408667 A4 19910814; EP 0408667 B1 19940119; JP H03501408 A 19910328
DOCDB simple family (application)
US 8901641 W 19890421; DE 68912584 T 19890421; EP 89905949 A 19890421; JP 50585689 A 19890421