Title:
【発明の名称】ダウンホール電磁地震源
Document Type and Number:
Japanese Patent JPH01500055
Kind Code:
A
Abstract:
The present invention is a downhole seismic source capable of generating seismic forces in excess of 1000 newtons. The source produces seismic waves for seismic applications, particularly cross borehole measurements and vertical seismic profiling. Coupled with motion sensing devices, the present invention also performs as a seismic logging tool. The source is comprised of an outer housing, a means for clamping the source securely to the wellbore, and a linear electromagnetic actuator which utilizes permanent magnetic material having remanent magnetic field exceeding about 0.9 T such as rare earth permanent magnetics. The source has a diameter of about 12.5 cm to fit within a typical wellbore and the acuator has a length of about 1 meter.
Inventors:
Paulsson, Bjorn N. P.
Application Number:
JP50210987A
Publication Date:
January 12, 1989
Filing Date:
March 18, 1987
Export Citation:
Assignee:
Chevron Research Company
International Classes:
G01V1/143; E21B23/01; G01V1/06; G01V1/155; G01V1/38; G01V1/40; G01V11/00; (IPC1-7): G01V1/143
Domestic Patent References:
| JPS5852191A | 1983-03-28 |
Foreign References:
| US3221833A | 1965-12-07 | |||
| US3202886A | 1965-08-24 |
Attorney, Agent or Firm:
Akira Asamura (3 outside)