Apparatus and method for attenuating tube waves in a borehole
AssigneeTomoseis Corporation
InventorJames Minto
Life of this patent
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Abstract
In one embodiment the invention comprises a method of gathering borehole seismic data in which a borehole acoustic instrument is lowered into a borehole in the earth's surface along with a canister positioned about the instrument and a second open bottomed canister positioned below the instrument. The canisters are at least partially filled with gas after the canisters are lowered into borehole. In another embodiment the invention comprises an apparatus for reflecting tube waves in a fluid-filled borehole which includes a canister having a diameter adapted to enable the canister to be deployed within the fluid-filled borehole, and having an open lower end, and an enclosed upper end with an aperture through the upper end adapted for sealing engagement between said upper end and a conduit.
Claims25
A method of gathering borehole seismic data comprising:
- lowering into a borehole in the earth's surface by means of a wireline
- (a) a borehole acoustic instrument;
- (b) a first open bottom, enclosed top canister positioned above said borehole instrument;
- and
- (c) a second open bottom, enclosed top canister positioned below said borehole instrument;
- and
- at least partially filling said first and second canisters with a gas after said canisters have been lowered into said borehole.
A method of gathering borehole seismic data comprising:
- lowering into a borehole in the earth's surface by means of a wireline
- (a) a borehole acoustic instrument comprising a borehole seismic source and a borehole seismic receiver;
- (b) a first plurality of open bottom, enclosed top canisters positioned above said borehole receiver on said wireline;
- (c) a second plurality of open bottom, enclosed top canisters positioned below said borehole receiver on said wireline;
- (d) a third plurality of open bottom, enclosed top canisters positioned above said borehole source on said wireline;
- (e) a fourth plurality of open bottom, enclosed top canisters positioned below said borehole source on said wireline;
- and
- filling the lower most of said canisters with a gas after said canisters have been lowered into the borehole by said wireline and allowing said gas to percolate upwardly in said borehole fluid from below said lower most canister and successively substantially filling with gas the other of said canisters included in said first, second, third and fourth plurality of canisters.
An apparatus for reflecting tube waves in a fluid-filled borehole comprising:
- a substantially cylindrical canister having a diameter adapted to enable said canister to be deployed within said fluid-filled borehole, and having an enclosed upper end and an open lower end;
- means for attaching said substantially cylindrical canister to a wireline for conveying said canister into said borehole;
- and
- means for at least partially filling said canister with a gas after said canister is deployed in said borehole.
Dependencies are inferred from the claim text.