Seismic source

US5301169A · kind A · utility

Assignee

• The Secretary of State for Trade and Industry in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland · GB

Inventors

• Roy Baria · Leatherhead, GB
• Michael Manning · Truro, GB
• Michael Allcock · Worcester, GB

Key dates

• Filing date: Nov 15, 1991
• Grant date: Apr 5, 1994
• Expiry date: Nov 15, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G01V1/157
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A source of seismic waves operable within a borehole filled with liquid crises a module supported by a cable. The module includes means to generate a high voltage and to charge a bank of capacitors, and means to connect the capacitors across a pair of electrodes forming a spark gap. The electrodes are immersed in liquid at the same pressure as the borehole liquid and acoustically continuous with it, and are separated by a gap of width between 0.5 and 20 mm. If the gap is greater than about 5 mm, both the electrodes should be covered with insulation except at the positions where the spark is to be formed. The module can operate automatically at considerable depths and at high pressures.