Sonic data logging system
AssigneeSchlumberger Technology Corporation
InventorsMasafumi Fukuhara, Mauricio Tejada
Life of this patent
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Abstract
A sonic logging method involves the pre-processing of a detection signal by a downhole processing device to determine the arrival time of a sonic signal at a receiver which is then transmitted to the surface. A suitable sonic logging downhole tool includes a control device for controlling generation and reception of the sonic signal, an A-D converter for digitizing the detected signal at a predetermined sampling interval, a first memory for storing the digitized waveform, a second memory for storing a program for processing the digitized waveform, and a microprocessor capable of executing the stored program so as to determine an arrival time of the sonic signal arriving at the receiver.
Claims18
A sonic logging method for determining characteristics of a formation through which a borehole passes using a downhole tool which is located in the borehole so as to be moveable up and down and coupled to ground surface processing apparatus by means of a logging cable, the downhole tool including:
- (i) at least one sonic wave generator and at least once receiver spaced apart from each other;
- and (ii) a downhole processing device operatively coupled to the generator and receiver and also to the ground surface processing apparatus through the logging cable, the method comprising:
- (a) locating the downhole tool in the borehole;
- (b) generating a sonic wave signal with the at least one generator;
- (c) receiving the sonic wave signal with the at least one generator;
- (d) processing a received signal using the downhole processing device and determining an arrival time for the sonic wave signal at the receiver;
- and
- (e) transmitting the determined arrival time to the ground surface processing equipment through the logging cable.
A sonic logging method for determining characteristics of a formation through which a borehole passes using a downhole tool which is located in the borehole so as to be moveable up and down and operatively coupled to ground surface processing apparatus, the downhole tool including:
- (i) at least one sonic wave generator and at least one receiver spaced apart from each other;
- and (ii) a downhole processing device operatively coupled to the generator and receiver and in communication with the ground surface processing apparatus, the method comprising:
- (a) locating the downhole tool in the borehole;
- (b) generating a sonic wave signal with the at least one generator;
- (c) receiving the sonic wave signal with the at least one receiver;
- (d) processing a received signal using the downhole processing device and determining an arrival time for the sonic wave signal at the receiver;
- and
- (e) transmitting the determined arrival time to the ground surface processing equipment.
A sonic logging downhole tool for determining characteristics of a formation through which a borehole passes, comprising:
- (a) at least one sonic wave generator;
- (b) at least one receiver capable of receiving the sonic wave after it has traveled through the formation;
- (c) a control device for controlling the generation and reception of the sonic wave, the control device comprising:
- (i) an analog-to-digital converter for digitizing a detection signal waveform from the at least one receiver at a predetermined sampling interval;
- (ii) a first memory for storing the digitized waveform;
- (iii) a second memory for storing a predetermined program for processing the stored digitized waveform;
- and
- (iv) a microprocessor capable of executing the program stored in the second memory so as to process the digitized waveform stored in the first memory to determine an arrival time of a sonic wave generated by the generator and received by the receiver.
A sonic logging system for determining characteristics of a formation through which a borehole passes, comprising a ground surface processing apparatus, and a downhole tool in communication with the ground surface processing apparatus and comprising:
- (a) at least one sonic wave generator;
- (b) at least one receiver capable of receiving the sonic wave after it has traveled through the formation;
- (c) a control device for controlling the generation and reception of the sonic wave, the control device comprising:
- (i) an analog-to-digital converter for digitizing a detection signal waveform from the at least one receiver at a predetermined sampling interval;
- (ii) a first memory for storing the digitized waveform;
- (iii) a second memory for storing a predetermined program for processing the stored digitized waveform;
- and
- (iv) a microprocessor capable of executing the program stored in the second memory so as to process the digitized waveform stored in the first memory to determine an arrival time of a sonic wave generated by the generator and received by the receiver.
Dependencies are inferred from the claim text.