Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
191 words
Apparatus for determining while drilling the position of a gas-saturated rock formation in the vicinity of a borehole in the earth, comprising: (a) a rotary drill bit for generating periodic seismic waves as it drills into the earth; (b) a plurality of transducer means located on the surface at preselected positions for defining a first plurality of seismic wave paths between a first position of said drill bit on one side of said gas-saturated porous rock formation and said plurality of positions on the surface and a second plurality of seismic wave paths between at least a second position of said drill bit on said same side of said gas-saturated porous rock formation and said plurality of positions on the surface, said transducers simultaneously generating signals responsive to said seismic waves at said first and second drill bit positions; (c) means including frequency selection means connected to receive the signals generated by said transducers and generate signals representative of the amplitude and energy of the seismic wave transmitted through said first and second plurality of seismic wave paths at a selected harmonic of the rate of rotation of the drill bit;
Claim 2
Dependent Claim
191 words
Apparatus for determining while drilling the position of a gas-saturated rock formation in the vicinity of a borehole in the earth, comprising: (a) a rotary drill bit for generating periodic seismic waves as it drills into the earth; (b) a plurality of transducer means located on the surface at preselected positions for defining a first plurality of seismic wave paths between a first position of said drill bit on one side of said gas-saturated porous rock formation and said plurality of positions on the surface and a second plurality of seismic wave paths between at least a second position of said drill bit on said same side of said gas-saturated porous rock formation and said plurality of positions on the surface, said transducers simultaneously generating signals responsive to said seismic waves at said first and second drill bit positions; (c) means including frequency selection means connected to receive the signals generated by said transducers and generate signals representative of the amplitude and energy of the seismic wave transmitted through said first and second plurality of seismic wave paths at a selected harmonic of the rate of rotation of the drill bit;
Claim 3
Dependent Claim
50 words
(d) means for comparing the amplitude and energy of the simultaneously generated signals to identify signals corresponding to seismic waves traveling through said gas-saturated porous rock formation at said first and second locations; and (e) means for determining from the identified signals the position of the gas-saturated porous rock formation.
Claim 4
Dependent Claim
50 words
(d) means for comparing the amplitude and energy of the simultaneously generated signals to identify signals corresponding to seismic waves traveling through said gas-saturated porous rock formation at said first and second locations; and (e) means for determining from the identified signals the position of the gas-saturated porous rock formation.
Claim 5
Dependent Claim
29 words
Apparatus as in claim 1 wherein said means including frequency selection means includes bandpass filters tuned to the selected harmonic of the rate of rotation of the drill bit.
Claim 6
Dependent Claim
60 words
Apparatus as in claim 1 wherein said means including frequency selection means includes a corresponding set of spectrum analyzers for receiving said signals, their time bases or time clocks being synchronized to the rate of rotation of the drill pipe supporting the drill bit, and whose output displays allow direct measurement of amplitude and energy at the selected harmonic frequency.
Claim 7
Dependent Claim
48 words
Apparatus as in claim 3 wherein said means for comparing the amplitude and energy of each of said signals generated at each of said positions includes an adaptive noise cancelling system for receiving said signals and signals representing noise and providing low noise signals to the spectrum analyzer.
Claim 8
Dependent Claim
22 words
Apparatus as in claim 3 in which said spectrum analyzers ensemble average the facsimile signals to enhance the signal to noise ratio.