Well surveying instrument sensor

Claim 2

A surveying instrument sensor comprising: (a) a sealed casing comprising first and second sections of pipe of a size permitting it to be lowered into a well pipe or the like containing within said first section: (i) a gimbal supported for rotation within said casing; (ii) a torquer coupled to rotate said gimbal; (iii) a first two-axis flexure suspended gyro supported on said gimbal with its spin axis perpendicular to the axis of said gimbal and one of its sensitive axes aligned with the axis of said gimbal; (iv) a second two-axis flexure suspended gyro supported on said gimbal with its spin axis perpendicular to the axis of said gimbal and one of its sensitive axes aligned with the axis of said gimbal; (v) means for coupling the output of said first gyro to said torquer to form a gimbal stabilized loop; (vi) means for coupling the outputs and torquing inputs of said second gyro into rate capture loops; (vii) means for obtaining from said rate captured loops rate output signals; and said second section of pipe having therein electronic circuit boards; (b) a slip ring/brush block mounted respectively to said gimbal and said casing for coupling signals to and from said torquer and said gyros and said circuit boards; and (c) means for connecting a cable to an end of said casing to remotely supply power thereto and receive signals therefrom as said casing is lowered into a well pipe or the like.

Claim 3

Apparatus according to claim 1 and further including a connector having a female portion and a male portion, one of said portions receiving the outputs of said slip ring/brush block assembly and the other the connections to said circuit boards.

Claim 4

Apparatus according to claim 1 wherein said means for coupling said first gyro and gimbal stabilized loop comprise a servo amplifier obtaining its input from the sensitive axis of said first gyro and providing its output to said torquer.

Claim 5

Apparatus according to claim 3 wherein said amplifier is mounted on one of said circuit boards.

Claim 6

Apparatus according to claim 1 wherein said means for coupling said second gyro in a rate capture loop comprises first and second amplifiers receiving inputs respectively from the outputs of the sensitive axes of said second gyro and providing their outputs to the torquers of said gyro, the outputs of said amplifiers providing the rate output of said system.

Claim 7

Apparatus according to claim 5 wherein said amplifiers comprise digital rate amplifiers.

Claim 8

Apparatus according to claim 6 wherein said amplifiers are mounted on one of said circuit boards.

Claim 9

A surveying instrument sensor for surveying well pipes comprising: (a) a first section of pipe; (b) a gimbal disposed for rotation therein; (c) a torquer for rotating said gimbal; (d) first and second two-axis flexure suspended gyros mounted on said gimbal, one of said gyros having its spin axis aligned with the axis of said gimbal and the other having its spin axis perpendicular thereto; (e) a brush block assembly coupled respectively to said pipe section and said gimbal; (f) each of said gyros having first and second sensitive axis outputs and first and second torquer inputs, the inputs and outputs of said gyros and the input to said torquer coupled through said slip ring/brush block assembly; (g) a connector disposed at said brush block assembly receiving inputs from the other of said slip rings or brush block; (h) a second pipe section adapted to mate with said first pipe section; (i) a connector at said second pipe section for mating with said first connector; (j) at least one circuit board in said second pipe section having inputs and outputs coupled to said connector; (k) and a third connector for coupling signal and power out of said second pipe section to a cable which can be lowered into a well with said two pipe sections; and (l) said circuit board having thereon: i. first servo amplifier receiving as an input the output of the sensitive axis of said first gyro which is aligned with said gimbal axis and providing an output to said torquer to thereby establish operation of said first gyro in a gimbal stabilized mode insuring that said gimbal always is pointed in the same direction despite any rotation of said pipe sections; ii. a second amplifier receiving an output from one of the sensitive axis of the said second gyro and providing its output to the torquer for the other axis of said second gyro; iii. a third amplifier receiving an input from the other sensitive axis of said gyro and providing its output to the torquer for the one sensitive axis of said second gyro thereby placing the two sensitive axes of said second gyro in rate capture; and iv. outputs from said third and fourth amplifiers being coupled through said third connector, whereby from the rate information provided therefrom, along with the knowledge of the distance which said sensor has been lowered into said well pipe, an accurate plot of the path of said well pipe can be established.

Claim 10

A surveying instrument sensor for surveying well pipes comprising: (a) a first section of pipe; (b) a gimbal disposed for rotation therein; (c) a torquer for rotating said gimbal; (d) first and second two-axis flexure suspended gyros mounted on said gimbal, one of said gyros having its spin axis aligned with the axis of said gimbal and the other having its spin axis perpendicular thereto; (e) a brush block assembly coupled respectively to said pipe section and said gimbal; (f) each of said gyros having first and second sensitive axis outputs and first and second torquer inputs, the inputs and outputs of said gyros and the input to said torquer coupled through said slip ring/brush block assembly; (g) a connector disposed at said brush block assembly receiving inputs from the other of said slip rings or brush block; (h) a second pipe section adapted to mate with said first pipe section; (i) a connector at said second pipe section for mating with said first connector; (j) at least one circuit board in said second pipe section having inputs and outputs coupled to said connector; (k) and a third connector for coupling signal and power out of said second pipe section to a cable which can be lowered into a well with said two pipe sections; and (l) said circuit board having thereon: i. first servo amplifier receiving as an input the output of the sensitive axis of said first gyro which is aligned with said gimbal axis and providing an output to said torquer to thereby establish operation of said first gyro in a gimbal stabilized mode insuring that said gimbal always is pointed in the same direction despite any rotation of said pipe sections; ii. a second amplifier receiving an output from one of the sensitive axis of the said second gyro and providing its output to the torquer for the other axis of said second gyro; iii. a third amplifier receiving an input from the other sensitive axis of said gyro and providing its output to the torquer for the one sensitive axis of said second gyro thereby placing the two sensitive axes of said second gyro in rate capture; and iv. outputs from said third and fourth amplifiers being coupled through said third connector, whereby from the rate information provided therefrom, along with the knowledge of the distance which said sensor has been lowered into said well pipe, an accurate plot of the path of said well pipe can be established.

Claim 11

Apparatus according to claim 8 and further including a resolver disposed within said first pipe section, said resolver and torquer being disposed at opposite ends thereof with said gimbal therebetween, said gimbal supported in preloaded bearings within said resolver and torquer, the connections to and from said resolver being coupled through said slip ring/brush block assembly, first and second connectors and third connector, whereby, prior to use, said gimbal can be aligned in a predetermined direction by operating said torquer and observing the output of said resolver.