US 4,789,968 A · Method and system for seismic exploration employing a dual-dipole hydrophone streamer

Abstract

A seismic exploration method and system employing a streamer that houses at least one pair of orthogonally mounted hydrophones. The streamer may be operated downhole in a well, or may be towed in a body of water by a marine vessel. In the downhole embodiment, the invention permits detection of seismic signals of interest with suppression of noise due to tube waves and (dipole and monopole) modal waves propagating in and along the well, and without the need for locking the seismic detectors to the wall of the well. In the marine embodiment, the invention permits selective detection of waves incident from any incidence direction of interest (including the horizontal and vertical directions). In all embodiments, the incidence angle of the detected seismic wave is determined. The amplitude of the detected wave may also be determined from the incidence angle and the amplitude components detected at each hydrophone.

Claims18

Dependent claims

A seismic exploration method employing a streamer having a longitudinal axis and including at least one pair of dipole hydrophones;

each of the dipole hydrophones in the pair having an axis and a sensitivity to wave energy that is a function of the angle of incidence of the wave on the dipole hydrophone with respect to the axis, including the steps of:
(a) orienting the dipole hydrophones in the at least one pair so that the axes of the dipole hydrophones are perpendicular to the longitudinal axis of the streamer and oriented at an angle with respect to each other;
(b) generating a seismic wave that will propagate in a subterranean formation;
(c) detecting at each of the dipole hydrophones in the at least one pair of dipole hydrophones, a signal corresponding to energy in the wave that has reflected from a reflector in the formation;
and
(d) determining the detected wave energy's incidence angle is a plane perpendicular to the streamer's longitudinal axis from the signals detected at each of the dipole hydrophones and the angle at which the axes of the dipole hydrophones are oriented.

3 more elements

Dependencies are inferred from the claim text.

Method and system for seismic exploration employing a dual-dipole hydrophone streamer

Life of this patent

Method and system for seismic exploration employing a dual-dipole hydrophone streamer

Life of this patent

Abstract

Claims18