Logging method and system

Claim 3

The method of claim 1 wherein said acoustical signal is generated fluidically with fluid pumped down the borehole.

Claim 4

The method of claim 2 wherein said acoustical signal is generated by the steps of: diverting at least a portion of thE fluid flowing down the borehole into two channels; switching alternately fluid flow from one channel to another to generate out-of-phase outputs; inverting the phase of one output to match the phase of the other output; and coupling in phase flows with said compliance.

Claim 5

The method of claim 1 wherein said detection and recording operations are carried out at the surface of the earth.

Claim 6

The method of claim 4 wherein said detection operation is carried out with seismic detector means coupled to the earth.

Claim 7

The method of claim 4 wherein said detection operation is carried out with transducer means acoustically coupled with fluid in the borehole.

Claim 10

The method of claim 7 wherein said acoustical signal is generated fluidically with fluid pumped down the borehole.

Claim 11

The method of claim 8 wherein said acoustical signal is generated by the steps of: diverting at least a portion of the fluid flowing down the borehole into two channels; switching alternately fluid flow from one channel to another to generate out-of-phase outputs; inverting the phase of one output to match the phase of the other output; and coupling in phase flows with said compliance.

Claim 12

The method of claim 7 wherein said detection and recording operations are carried out at the surface of the earth.

Claim 13

The method of claim 10 wherein said detection operation is carried out with seismic detector means coupled to the earth.

Claim 14

The method of claim 10 wherein said detection operation is carried out with transducer means acoustically coupled with fluid in the borehole.

Claim 17

The logging system of claim 13 wherein said acoustic oscillator is a fluidic oscillator.

Claim 18

In a rotary method of drilling boreholes in the earth in which a drill bit is suspended from a drill string and rotated while circulating a drilling fluid through the drill string, drill bit, and up the annulus between the drill bit and borehole and wherein an acoustic vibration oscillator is operated near the bottom of the borehole to produce acoustic vibrations in the borehole fluid, said acoustic vibration oscillator being adapated to be operated by a portion of the fluid pumped down the drill string and having an output to be acoustically coupled with a selected acoustic cavity, a portion of which is defined by the walls of the borehole, the method of simultaneously logging the subsurface formations traversed by the borehole, comprising the steps of; matching an acoustical oscillator operatinG frequency with the resonant frequency of an acoustical circuit that includes a coupler and a selected compliance to be partially formed by the wall of a borehole such that the oscillator will generate a selected signal which changes in response to compliance changes; generating acoustic vibrations with said oscillator; advancing said oscillator and said coupler in said borehole while drilling to expose differing portions of the borehole wall to sense compliance changes; detecting the acoustic vibrations generated; and recording in correlation with depth the acoustic vibrations detected to obtain a record of the changes of the frequency of the acoustic vibrations in response to the changes in subsurface formations.

Claim 19

In a rotary method of drilling boreholes in the earth in which a drill bit is suspended from a drill string and rotated while circulating a drilling fluid through the drill string, drill bit, and up the annulus between the drill bit and borehole and wherein an acoustic vibration oscillator is operated near the bottom of the borehole to produce acoustic vibrations in the borehole fluid, said acoustic vibration oscillator being adapated to be operated by a portion of the fluid pumped down the drill string and having an output to be acoustically coupled with a selected acoustic cavity, a portion of which is defined by the walls of the borehole, the method of simultaneously logging the subsurface formations traversed by the borehole, comprising the steps of; matching an acoustical oscillator operatinG frequency with the resonant frequency of an acoustical circuit that includes a coupler and a selected compliance to be partially formed by the wall of a borehole such that the oscillator will generate a selected signal which changes in response to compliance changes; generating acoustic vibrations with said oscillator; advancing said oscillator and said coupler in said borehole while drilling to expose differing portions of the borehole wall to sense compliance changes; detecting the acoustic vibrations generated; and recording in correlation with depth the acoustic vibrations detected to obtain a record of the changes of the frequency of the acoustic vibrations in response to the changes in subsurface formations.

Claim 20

In a rotary drilling system wherein a drill bit is suspended from a drill string and rotated while circulating a drilling fluid through the drill string, drill bit nozzles and up the annulus between the drill bit and borehole and wherein an acoustic vibration oscillator has its output coupled with said fluid near the bottom of the borehole to produce acoustic vibrations in the borehole fluid, said acoustic vibration oscillator being adapted to be operated by the fluid pumped down the drill string and having an output to be acoustically coupled with an acoustic cavity, a portion of which is defined by the walls of the borehole, the combination therewith of: coupler means to acoustically couple said oscillator output with the drilling fluid on the exterior of the bit through the drill string above said bit nozzles, said oscillator, coupler, and a selected compliance, partially defined by the wall of a borehole, being matched such that the oscillator will generate a selected signal which changes in response to compliance changes sensed by the oscillator; detector means for detecting the acoustic vibrations generated; and recording means for recording the acoustic vibrations detected to obtain a measure of the frequency changes of the acoustic vibrations in response to the changes in subsurface formations.

Claim 21

In a rotary drilling system wherein a drill bit is suspended from a drill string and rotated while circulating a drilling fluid through the drill string, drill bit nozzles and up the annulus between the drill bit and borehole and wherein an acoustic vibration oscillator has its output coupled with said fluid near the bottom of the borehole to produce acoustic vibrations in the borehole fluid, said acoustic vibration oscillator being adapted to be operated by the fluid pumped down the drill string and having an output to be acoustically coupled with an acoustic cavity, a portion of which is defined by the walls of the borehole, the combination therewith of: coupler means to acoustically couple said oscillator output with the drilling fluid on the exterior of the bit through the drill string above said bit nozzles, said oscillator, coupler, and a selected compliance, partially defined by the wall of a borehole, being matched such that the oscillator will generate a selected signal which changes in response to compliance changes sensed by the oscillator; detector means for detecting the acoustic vibrations generated; and recording means for recording the acoustic vibrations detected to obtain a measure of the frequency changes of the acoustic vibrations in response to the changes in subsurface formations.