Well logging system

Claim 1

A system for logging a borehole which traverses earth formations comprising: a sonde adapted to be passed along the borehole, said sonde including means for generating a shortduration, fast rising and fast decaying first pulse having an amplitude representative of at least one parameter determined in the borehole; a transmission line having a sending end, coupled to the means for generating the initial pulse, and a receiving end located at the surface of the earth, the first pulse being introduced at said sending end and distortedly transmitted along said line to said receiving end at which latter end the first pulse is received as a distorted long-duration, slow rising and slow decaying second pulse having an attenuated amplitude; a linear amplifier for amplifying the second pulse and thereby producing an amplified distorted third pulse; a Schmitt trigger responsive to the third pulse for producing a long-duration fourth pulse; a first multivibrator responsive to the fourth pulse for producing a fifth pulse; a second multivibrator responsive to the fourth pulse for producing a sixth pulse; a third multivibrator responsive to the sixth pulse for producing a seventh pulse; delay means for translating the third pulse in the form of a time-delayed eighth pulse; a first cathode follower amplifier for amplifying the eighth pulse and thereby producing a ninth pulse; storage means for storing a potential having a magnitude substantially equal to the peak amplitude of the ninth pulse; first gating means responsive to the fifth pulse for gating the potential stored in the storage means in the form of a 10th pulse having a peak amplitude substantially equal to the magnitude of the stored potential; a second cathode follower for amplifying the 10th pulse and thereby producing an 11th pulse; second gating means responsive to the seventh pulse for gating the 11th pulse; cathode follower and noise discriminator means for receiving the 11th pulse when gated from the second gating means and for producing a 12th pulse which has an ampLitude linearly related to the first pulse and similar duration, rise and decay times.

Claim 2

A system for logging a borehole which traverses earth formations comprising: a sonde adapted to be passed along the borehole, said sonde including means for generating a shortduration, fast rising and fast decaying first pulse having an amplitude representative of at least one parameter determined in the borehole; a transmission line having a sending end, coupled to the means for generating the initial pulse, and a receiving end located at the surface of the earth, the first pulse being introduced at said sending end and distortedly transmitted along said line to said receiving end at which latter end the first pulse is received as a distorted long-duration, slow rising and slow decaying second pulse having an attenuated amplitude; a linear amplifier for amplifying the second pulse and thereby producing an amplified distorted third pulse; a Schmitt trigger responsive to the third pulse for producing a long-duration fourth pulse; a first multivibrator responsive to the fourth pulse for producing a fifth pulse; a second multivibrator responsive to the fourth pulse for producing a sixth pulse; a third multivibrator responsive to the sixth pulse for producing a seventh pulse; delay means for translating the third pulse in the form of a time-delayed eighth pulse; a first cathode follower amplifier for amplifying the eighth pulse and thereby producing a ninth pulse; storage means for storing a potential having a magnitude substantially equal to the peak amplitude of the ninth pulse; first gating means responsive to the fifth pulse for gating the potential stored in the storage means in the form of a 10th pulse having a peak amplitude substantially equal to the magnitude of the stored potential; a second cathode follower for amplifying the 10th pulse and thereby producing an 11th pulse; second gating means responsive to the seventh pulse for gating the 11th pulse; cathode follower and noise discriminator means for receiving the 11th pulse when gated from the second gating means and for producing a 12th pulse which has an ampLitude linearly related to the first pulse and similar duration, rise and decay times.

Claim 4

A system for a logging borehole which traverses earth formations comprising: a sonde adapted for traversing a borehole; means, in said sonde, for generating a first electrical pulse representative of at least one parameter determinable in the borehole, said first electrical pulse having a relatively short duration period and a quickly rising as well as a quickly decaying period; a transmission line having a sending end and a receiving end, said sending end of said transmission line being situated in the borehole while the receiving end thereof is situated at the surface of the earth, said sending end of said transmission line being coupled to said means for generating said first electrical pulse whereby said first electrical pulse is transmitted along said transmission line to said receiving end thereof whereat said first pulse is received as a second pulse, said second pulse having a relatively long duration, an attenuated amplitude, a slow rise period and a slow decay period; a pick-off circuit having input terminal means and output terminal means, the input terminal means of said pick-off circuit being coupled to the receiving end of said transmission line; a linear amplifier having input terminal means and output terminal means, the input terminal means of said linear amplifier being coupled with the output terminal means of said pick-off circuit; delay means having input terminal means and output terminal means, the input terminal means of said delay means being coupled with the output terminal means of said linear amplifier; a first cathode follower amplifier having input terminal means and output terminal means, the input terminal means of said cathode follower amplifier being coupled with the output terminal means of said delay means; means for storing a voltage having input terminal means and output terminal means, the input terminal means of said means for storing a voltage being coupled with said output terminal means of said first cathode follower amplifier; first gate means having input terminal means and output terminal means, the input terminal means of said first gate means being coupled with the output terminal means of said means for storing a voltage; second cathode follower amplifier means having input terminal means and output terminal means, the input terminal means of said second cathode follower amplifier means being coupled with the output terminal means of said first gate means; second gate means having input terminal means and output terminal means, the input terminal means of said second gate means being coupled with the output terminal means of said second cathode follower amplifier; third cathode follower amplifier means having input terminal means and output terminal means, the input terminal means of said third cathode follower amplifier means being coupled with the output terminal means of said second gate means; noise discriminator means having input terminal means and output terminal means, said input terminal means of said noise discriminator means being coupled with said output terminal means of said third cathode follower amplifier means; pulse height analyzing means having input terminal means, the input terminal means of said pulse height analyzing means being coupled with the output terminal means of said noise discriminator means; Schmitt trigger means having input terminal means and output terminal means, the input terminal means of said Schmitt trigger means being coupled with said output terminal means of said linear amplifier; first multivibrator means having input terminal means and output terminal means, the input terminal means of said first multivibrator means being coupled with the output terminal means of said Schmitt trigger, said output terminal meanS of said first multivibrator means being coupled with the input terminal means of said first gate means; second multivibrator means having input terminal means and output terminal means, said input terminal means of said second multivibrator means being coupled with said output terminal means of said Schmitt trigger, third multivibrator means having input terminal means and output terminal means, said input terminal means of said third multivibrator means being coupled with said second multivibrator means, said output terminal means of said second multivibrator means geing coupled with said input terminal means of said second gate means; and means for recording output signals from the output terminal means in correlation with the depth of said sonde in the borehole.

Claim 5

A system for a logging borehole which traverses earth formations comprising: a sonde adapted for traversing a borehole; means, in said sonde, for generating a first electrical pulse representative of at least one parameter determinable in the borehole, said first electrical pulse having a relatively short duration period and a quickly rising as well as a quickly decaying period; a transmission line having a sending end and a receiving end, said sending end of said transmission line being situated in the borehole while the receiving end thereof is situated at the surface of the earth, said sending end of said transmission line being coupled to said means for generating said first electrical pulse whereby said first electrical pulse is transmitted along said transmission line to said receiving end thereof whereat said first pulse is received as a second pulse, said second pulse having a relatively long duration, an attenuated amplitude, a slow rise period and a slow decay period; a pick-off circuit having input terminal means and output terminal means, the input terminal means of said pick-off circuit being coupled to the receiving end of said transmission line; a linear amplifier having input terminal means and output terminal means, the input terminal means of said linear amplifier being coupled with the output terminal means of said pick-off circuit; delay means having input terminal means and output terminal means, the input terminal means of said delay means being coupled with the output terminal means of said linear amplifier; a first cathode follower amplifier having input terminal means and output terminal means, the input terminal means of said cathode follower amplifier being coupled with the output terminal means of said delay means; means for storing a voltage having input terminal means and output terminal means, the input terminal means of said means for storing a voltage being coupled with said output terminal means of said first cathode follower amplifier; first gate means having input terminal means and output terminal means, the input terminal means of said first gate means being coupled with the output terminal means of said means for storing a voltage; second cathode follower amplifier means having input terminal means and output terminal means, the input terminal means of said second cathode follower amplifier means being coupled with the output terminal means of said first gate means; second gate means having input terminal means and output terminal means, the input terminal means of said second gate means being coupled with the output terminal means of said second cathode follower amplifier; third cathode follower amplifier means having input terminal means and output terminal means, the input terminal means of said third cathode follower amplifier means being coupled with the output terminal means of said second gate means; noise discriminator means having input terminal means and output terminal means, said input terminal means of said noise discriminator means being coupled with said output terminal means of said third cathode follower amplifier means; pulse height analyzing means having input terminal means, the input terminal means of said pulse height analyzing means being coupled with the output terminal means of said noise discriminator means; Schmitt trigger means having input terminal means and output terminal means, the input terminal means of said Schmitt trigger means being coupled with said output terminal means of said linear amplifier; first multivibrator means having input terminal means and output terminal means, the input terminal means of said first multivibrator means being coupled with the output terminal means of said Schmitt trigger, said output terminal meanS of said first multivibrator means being coupled with the input terminal means of said first gate means; second multivibrator means having input terminal means and output terminal means, said input terminal means of said second multivibrator means being coupled with said output terminal means of said Schmitt trigger, third multivibrator means having input terminal means and output terminal means, said input terminal means of said third multivibrator means being coupled with said second multivibrator means, said output terminal means of said second multivibrator means geing coupled with said input terminal means of said second gate means; and means for recording output signals from the output terminal means in correlation with the depth of said sonde in the borehole.