DRILLING-FLUID CONTROL-MONITORING APPARATUS

• US 3,726,136 A
• Filed: 12/17/1970
• Issued: 04/10/1973
• Est. Priority Date: 12/17/1970
• Status: Expired due to Term

• Current Assignee: George W. Mckean, Hugh H. Benson
• Original Assignee: George W. Mckean, Hugh H. Benson
• Inventors: McKean, George W., Benson, Hugh H.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/099,136
• Time in Patent Office: 845 Days
• Field of Search: 73/155,432HA 175/38,48 166/250
• US Class Current: 73/152.21
• CPC Class Codes: E21B 21/08 Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure valve arrangements therefor E21B21/10

Abstract

A control-monitoring apparatus, which is adapted to cooperate in a drilling-fluid circulation system, having a level indicating apparatus to sense the level change of the drilling-fluid in the fluid-pits and to provide an output level-signal in response thereto; a pump transducer is connected to each pump, each pump transducer being connected to a flow register which provides an indication of the total volume of drilling-fluid being moved through a pump; and a return-flow indicator to provide an output return flow-signal indicative of the flow of drilling-fluid through the return flow line. The control-monitoring apparatus being constructed to provide the necessary drilling-fluid parameters during the drilling operation when the drilling-fluid is being circulated through the borehole, and during the initial filling of the borehole with drilling-fluid prior to the beginning of the drilling operation.

Claims

1. A control-monitoring apparatus adapted to cooperate in a drilling-fluid circulation system, comprising:

a fluid-pit for retaining a volume of drilling-fluid;

a pump connected between the fluid-pit means and the borehole pumping drilling-fluid from the fluid-pit means into the borehole in one position thereof;

a return flow pipeline connected between the borehole and the fluid-pit means, some of the drilling-fluid being returned to the fluid-pit means from the borehole via the return flow pipeline;

level indicating means disposed in the fluid-pit and being constructed and adapted to sense the level of the drillingfluid in the fluid-pit and to provide an output level-signal indicative of the sensed drilling-fluid level;

return flow indicator means connected to the return flow pipeline and being constructed and adapted to indicate the flow of drilling-fluid through the return flow pipeline, and to provide an output return flow-signal indicative of the sensed flow of drilling-fluid; and

a drilling-fluid control indication apparatus, comprising;

a first recorder means, comprising;

a first recorder drive means constructed and adapted to receive the output level-signal from the level indicating means and to provide an output drive-signal in response thereto;

a pit indicating means constructed and adapted to receive the output drive-signal from the first recorder drive means and to provide an output level indication-signal indicative of the drilling-fluid level in the fluid-pit; and

a second recorder means, comprising;

a second recorder drive means constructed and adapted to receive the output return flow-signal from the return flow indicator means and to provide an output drive-signal in response thereto; and

a return-flow indicating means constructed and adapted to Receive the output drive-signal from the second recorder drive means and to provide an output flow indication-signal indicative of the drilling-fluid flow through the return flow pipeline.

2. The control-monitoring apparatus of claim 1 defined further to include:

a pump transducer means connected to the pump and being constructed and adapted to provide an output flow-signal indicative of the volume of drilling-fluid being moved through the pump; and

wherein the drilling-fluid control indication apparatus is defined further to include;

a register means constructed and adapted to receive the output flow-signal from the pump transducer means to provide an output volume indication-signal indicative of the volume of drilling-fluid being moved through the pump.

3. The control-monitoring apparatus of claim 2 wherein the drilling-fluid control indication apparatus is defined further to include:

a continuity actuator means interposed between the pump transducer means and the register means and being constructed and adapted to receive the return flow-signal from the pump transducer means, the continuity actuator means having an actuated and a deactuated position, the return flow-signal from the pump transducer means being connected to the register means in an actuated position of the continuity actuator means and the pump transducer means being disconnected from the register means in a deactuated position of the continuity actuator means; and

means to actuate the continuity actuator means.

4. The control-monitoring apparatus of claim 3 wherein the continuity actuator means is further defined to include:

a relay means having an energized position and a de-energized position, the relay means being connected to the pump transducer means and the register means to establish continuity therebetween in an energized position of the relay means; and

means to energize the relay means in one position thereof.

5. The control-monitoring apparatus of claim 1 defined further to include:

a remote pit indicating means connected to the output drive-signal from the first recorder drive means and being constructed and adapted to provide a remote output level indication-signal indicative of the drilling-fluid level in the fluid-pits.

6. The control-monitoring apparatus of claim 1 wherein the drilling-fluid circulation system includes more than one fluid-pit, and wherein the level indicating means is defined further to include:

a level indicating means disposed in each fluid-pit, each level indicating means being connected in series to the other level indicating means to provide an output level-signal indicative of the total drilling-fluid level in the fluid-pits.

7. The control-monitoring apparatus of claim 6 wherein each level indicating means is further defined as being constructed and connected to the other level indicating means to provide an output level-signal indicative of the total drilling-fluid level change in the fluid-pits.

8. The control-monitoring apparatus of claim 7 wherein each level indicating means is further defined to include:

a float means disposed in the fluid-pit in contact with the drilling-fluid, the position of the float means being changed as the drilling-fluid level changes; and

a variable resistor means connected to the float means, the resistance of the resistor means being altered by the float means in response to a change of position of the float means, the resistor means being connected in series with the resistor means of the other level indicating means, the output level-signal being responsive to the total resistance change of the interconnected resistor means.

9. The control-monitoring apparatus of claim 7 wherein the first recorder drive means is further defined to include:

a first recorder shaft rotatingly supported in the first recorder means; and

a first recorder motor having an output drive shaft drivingly connected to the first recorder shaft, the first recorDer motor being constructed and adapted to receive the output level-signal from the level indicating means and to drivingly rotate the first recorder shaft in response to a change of the output level-signal.

10. The control-monitoring apparatus of claim 9 wherein the pit indicating means is further defined to include:

a dial-indicator secured to one end of the first recorder shaft, the dial-indicator movement thereby providing an instantaneous visual indication of the drilling-fluid level change in the fluid-pits.

11. The control-monitoring apparatus of claim 7 wherein the second recorder drive means is further to include:

a second recorder shaft rotatingly supported in the second recorder means; and

a second recorder motor having an output drive shaft drivingly connected to the second recorder shaft, the second recorder motor being constructed and adapted to receive the output flow indication signal from the return-flow indicating means and to drivingly rotate the second recorder shaft in response to a change of the output flow indication signal.

12. The control-monitoring apparatus of claim 11 wherein the return flow-indicating means is further defined to include:

a dial-indicator secured to one end of the secnd recorder shaft, the dial-indicator thereby providing an instantaneous, visual indication of the drilling-fluid flow in the return flow line.

13. The control-monitoring apparatus of claim 1 wherein the return flow indicator means is further defined to include:

a paddle means, having opposite ends, and being disposed in a portion of the return flow pipeline in a position wherein a portion of the paddle means contacts the drilling-fluid flowing in the return flow line, thereby moving the paddle means;

a paddle shaft having a portion thereof secured to one end portion of the paddle means, the movement of the paddle means by the drilling-fluid thereby rotating the paddle shaft;

a return flow transducer housing having a shaft aperture formed through a portion thereof, the shaft aperture sized to rotatingly receive a portion of the paddle shaft extending therethrough;

moisture-seal means connected to a portion of the paddle shaft and to a portion of the return flow transducer housing to provide a moisture-tight seal between paddle shaft and the return flow transducer housing; and

return flow transducer means supported in the return flow transducer housing and being connected to one end portion of the paddle shaft, the return flow transducer means being constructed and adapted to provide the output return flow-signal in response to the rotational movement of the paddle shaft.

14. A control-monitoring apparatus adapted to cooperate in a drilling-fluid circulation system, comprising:

a plurality of fluid-pits, each fluid-pit for retaining a volume of drilling fluid;

a pump connected between the fluid-pit means and the borehole pumping drilling-fluid from the fluid-pit means into the borehole in one position thereof;

a return flow pipeline connected between the borehole and the fluid-pit means, some of the drilling-fluid being returned to the fluid-pit means from the borehole via the return flow pipeline;

level indicating means disposed in each fluid-pit, each level indicating means being connected in series to the other level indicating means to provide an output level-signal indicative of the sensed drilling-fluid level and indicative of the total drilling-fluid level change in the fluid pits;

return flow indicator means connected to the return flow pipeline and being constructed and adapted to indicate the flow of drilling-fluid through the return flow pipeline, and to provide an output return flow-signal indicative of the sensed flow of drilling-fluid; and

a drilling-fluid control indication apparatus, comprising;

first recorder means, comprising;

first recorder drive means constructed and adapted to receive the output level-signal from the level indicating means and to provide an output drive-signal in response thereto, including;

first recorder shaft rotatingly supported in the first recorder means; and

a first recorder motor having an output drive shaft drivingly connected to the first recorder shaft, the first recorder motor being constructed and adapted to receive the output level-signal from the level indicating means and to drivingly rotate the first recorder shaft in response to a change of the output level-signal;

pit indicating means constructed and adapted to receive the output drive-signal from the first recorder drive means and to provide an output level indication-signal indicative of the drilling-fluid level in the fluid-pit, including;

a dial-indicator secured to one end of the first recorder shaft, the dial-indicator movement thereby providing an instantaneous visual indication of the drilling-fluid level change in the fluid-pits;

chart means supported in the first recorder means;

a recorder arm having a marking end, the marking end being positioned on a portion of the chart means and adapted to continuously mark the portion of the chart means thereunder; and

a control cam, having opposite ends, one end portion thereof and being connected to the end portion of the recorder arm opposite the marking end thereof, and the other opposite end of the control cam being connected to first recorder shaft, the control cam being moved by the rotation of the first recorder shaft, thereby positioning the marking end of the recorder arm on the chart means in response to the rotation of the drive shaft of the first recorder motor, the mark on the chart means made by the marking end thereby indicating the drilling-fluid level change in the fluid-pits over a predetermined period of time;

second recorder means, comprising;

a second recorder drive means constructed and adapted to receive the output return flow-signal from the return flow indicator means and to provide an output drive-signal in response thereto; and

a return-flow indicating means constructed and adapted to receive the output drive-signal from the second recorder drive means and to provide an output flow indication-signal indicative of the drilling-fluid flow through the return flow pipeline.

15. The control-monitoring apparatus of claim 14 wherein the first recorder means is defined further to include:

a high-low pit actuator means constructed and adapted to receive the output drive-signal of the first recorder drive means and to provide an output high-signal when the output drive-signal of the first recorder drive means reaches a preset high level and to provide an output low-signal when the output drive-signal of the first recorder means reaches a preset low level, thereby indicating a predetermined high and a predetermined low drilling-fluid level change in the fluid-pits.

16. The control-monitoring apparatus of claim 15 wherein the control cam includes;

a high cam surface and a low cam surface formed on a portion thereof; and

wherein the high-low pit actuator means is further defined to include;

a high-switch means constructed and adapted to provide the output high signal in an actuated position thereof, and being positioned and supported in the first recorder means to cooperate with the control cam, the high-switch means being actuated by the high cam surface in one position of the control cam; and

a low-switch means constructed and adapted to provide the output low signal in an actuated position thereof, and being positioned and supported in the first recorder means to cooperate with the control cam, the low-switch means being actuated by the low cam surface in one position of the control cam.

17. The control-monitoring apparatus of claim 16 wherein the high-low pit actuator means is further defined to include:

an elongated high screw means turningly supported in the first recorder means;

means to turn the high screw means;

an elongated low screw means turningly suPported in the first recorder means; and

means to turn the low screw means; and

wherein the high-switch means is further defined as being threadedly supported on the high screw means, the position of the high-switch means with respect to the high cam surface defining the actuating preset high level, the position of the high-switch means with respect to the high cam surface being altered by the turning of the high screw means, the actuating preset high level being thereby adjustable; and

wherein the low-switch means is further defined as being threadedly supported on the low screw means, the position of the low-switch means with respect to the low cam surface defining the actuating preset low level, the position of the low-switch means with respect to the low cam surface being altered by the turning of the low screw means, the actuating preset low level being thereby adjustable.

18. The control-monitoring apparatus of claim 14 wherein the high-low pit actuator means is further defined to include:

a high-switch means having an opened and a closed position, the high-switch means being adapted to receive the output drive-signal of the first recorder drive means, the high-switch means being moved to the closed position when the output drive-signal of the first recorder drive means reaches a preset high level, thereby providing an output high signal in the closed position of the high-switch means;

a low-switch means having an opened and a closed position, the low-switch means being adapted to receive the output drive-signal of the first recorder drive means, the high-switch means being moved to the closed position when the output drive-signal of the first recorder drive means reaches a preset low level, thereby providing an output low signal in the closed position of the low-switch means;

a high level indicating means connected to the high-switch means and being connected thereto and adapted to provide a high level indication in the closed position of the high-switch means; and

a low level indicating means connected to the low-switch means and being connected thereto and adapted to provide a low level indication in the closed position of the low-switch means.

19. The control-monitoring apparatus of claim 18 wherein the high level indicating means and the low level indicating means each are defined further to include:

a lamp indicator means to provide a visual indication; and

a speaker means to provide an audible indication.

20. A control-monitoring apparatus adapted to cooperate in a drilling-fluid circulation system, comprising:

a plurality of fluid-pits, each fluid-pit for retaining a volume of drilling-fluid;

a pump connected between the fluid-pit means and the borehole pumping drilling-fluid from the fluid-pit means into the borehole in one position thereof;

level indicating means disposed in each fluid-pit, each level indicating means being connected in series to the other level indicating means to provide an output level-signal indicative of the sensed drilling-fluid level and indicative of the total drilling-fluid level change in the fluid-pits;

return flow indicator means connected to the return flow pipeline and being constructed and adapted to indicate the flow of drilling-fluid through the return flow pipeline, and to provide an output return flow-signal indicative of the sensed flow of drilling-fluid; and

a drilling-fluid control indication apparatus comprising;

first recorder means, comprising;

a first recorder drive means constructed and adapted to receive the output level-signal from the level indicating means and to provide an output drive-signal in response thereto;

a pit indicating means constructed and adapted to receive the output drive-signal from the first recorder drive means and to provide an output level indication-signal indicative of the drilling-fluid level in the fluid-pit; and

second recorder means, comprising;

a second recorder drive Means constructed and adapted to receive the output return flow-signal from the return flow indicator means and to provide an output drive-signal in response thereto, including;

a second recorder shaft rotatingly supported in the second recorder means; and

a second recorder motor having an output drive shaft drivingly connected to the second recorder shaft, the second recorder motor being constructed and adapted to receive the output flow indication signal from the return-flow indicating means and to drivingly rotate the second recorder shaft in response to a change of the output flow indication signal;

return flow indicating means constructed and adapted to receive the output drive-signal from the second recorder drive means and to provide an output flow indication-signal indicative of the drilling-fluid flow through the return flow pipeline, comprising;

a dial-indicator secured to one end of the second recorder shaft, the dial-indicator thereby providing an instantaneous, visual indication of the drilling-fluid flow in the return flow line;

chart means supported in the second recorder means;

a recorder arm having a marking end, the marking end being markingly positioned on a portion of the chart means and adapted to continuously mark the portion of the chart means thereunder; and

a control cam, having opposite ends, one end portion thereof being connected to the end portion of the recorder arm opposite the marking end thereof, and the other opposite end of the control cam being connected to the second recorder shaft, the control cam being moved by the rotation of the second recorder shaft, thereby positioning the marking end of the recorder arm on the chart means in response to the rotation of the drive shaft of the second recorder motor, the mark on the chart means made by the marking end thereby indicating the flow of drilling-fluid in the return flow pipeline over a predetermined period of time.

21. The control-monitoring apparatus of claim 20 wherein the second recorder means is defined further to include:

a high-low flow actuator means constructed and adapted to receive the output drive-signal from the second recorder drive means, and to provide an output high-signal when the output drive-signal of the second recorder drive means reaches a preset high level and to provide an output low-signal when the output drive-signal of the second recorder means reaches a preset low level, thereby indicating a predetermined high level and a predetermined low level of drilling-fluid flow in the return flow pipeline.

22. The control-monitoring apparatus of claim 21 wherein the control cam includes;

a high cam surface and a low cam surface formed on a portion thereof; and

wherein the high-low flow actuator means is defined further to include;

a high-switch means constructed and adapted to provide the output high signal in an actuated position thereof and being positioned and supported in the second recorder means to cooperate with the control cam, the high-switch means being actuated by the high cam surface, in one position of the control cam; and

a low-switch means constructed and adapted to provide the output low signal in an actuated position thereof, and being positioned in the second recorder means to cooperate with the control cam, the low-switch means being actuated by the low cam surface in one position of the control cam.

23. The control-monitoring apparatus of claim 22 wherein the high-low flow actuator means is defined further to include:

an elongated high screw means turningly supported in the second recorder means;

means to turn the high screw means;

an elongated low screw means turningly supported in the second recorder means; and

means to turn the low screw means; and

wherein the high-switch means is further defined as being threadedly supported on the high screw means, the position of the high screw means with respect to the high cam surface defining the actuating preset High level, the position of the high-switch means with respect to the high cam surface being altered by the turning of the high screw means, the actuating preset high level being thereby adjustable; and

wherein the low-switch means is further defined as being threadedly supported on the low screw means, the position of the low-switch means with respect to the low cam surface defining the actuating preset low level, the position of the low-switch means with respect to the low cam surface being altered by the turning of the low screw means, the actuating preset low level being thereby adjustable.

24. The control-monitoring apparatus of claim 20 wherein the high-low flow actuator means is further defined to include:

a high-switch means having an opened and a closed position, the high-switch means being adapted to receive the output drive-signal of the second recorder drive means, the high-switch means being moved to the closed position when the output drive-signal of the second recorder drive means reaches a preset high level, thereby providing an output high signal in the closed position of the high-switch means;

a low-switch means having an opened and a closed position, the low-switch means being adapted to receive the output drive-signal of the second recorder drive means, the high-switch means being moved to the closed position when the output drive-signal of the second recorder drive means reaches a preset low level, thereby providing an output low signal in the closed position of the low-switch means;

a high flow indicating means connected to the high-switch means and being connected thereto and adapted to provide a high flow indication in the closed position of the high-switch means; and

a low flow indicating means connected to the low-switch means and being connected thereto and adapted to provide a low flow indication in the closed position of the low-switch means.

25. The control-monitoring apparatus of claim 24 wherein the high flow indicating means and the low flow indicating means each are defined further to include:

a lamp indicator means to provide a visual indication; and

a speaker to provide an audible indication.

26. The control-monitoring apparatus of claim 24 is defined further to include:

a flow switch means having an opened and a closed position connected to the low-switch means, the flow switch means being in electrical continuity with the low flow indicating means in the closed position of the flow switch means and in the closed position of the low-switch means; and

means connected to the flow switch means, and being adapted to receive the output flow indication signal from the return flow indicating means and to close the flow switch means when the output flow indication signal indicates drilling-fluid flow in the return flow pipeline thereby establishing electrical continuity between the low flow indicating means and the flow switch means via the low-switch means, in a closed position of the low-switch means.

27. A control-monitoring apparatus adapted to cooperate in a drilling-fluid circulation system, comprising:

a plurality of fluid-pits, each fluid-pit for retaining a volume of drilling fluid;

a pump connected between the fluid-pit means and the borehole pumping drilling-fluid from the fluid-pit means into the borehole in one position thereof;

a return flow pipeline connected between the borehole and the fluid-pit means, some of the drilling-fluid being returned to the fluid-pit means from the borehole via the return flow pipeline;

level indicating means disposed in each fluid-pit, each level indicating means being connected in series to the other level indicating means to provide an output level-signal indicative of the sensed drilling-fluid level and indicative of the total drilling-fluid level change in the fluid-pits;

return flow indicator means connected to the return flow pipeline and being constructed and adapted to indicate the flow of drilling-fluid through the return flow pipeline, and to provide an output return flow-signal indicative of the sensed flow of drilling-fluid; and

a drilling-fluid control indication apparatus, comprising;

a first recorder means, comprising;

first recorder drive means constructed and adapted to receive the output level-signal from the level indicating means and to provide an output drive-signal in response thereto, including;

a first recorder shaft rotatingly supported in the first recorder means; and

a first recorder motor having an output drive shaft drivingly connected to the first recorder shaft, the first recorder motor being constructed and adapted to receive the output level-signal from the level indicating means and to drivingly rotate the first recorder shaft in response to a change of the output level-signal;

a pit indicating means constructed and adapted to receive the output drive-signal from the first recorder drive means and to provide an output level indication-signal indicative of the drilling-fluid level in the fluid-pit;

a first servo-control means having an output servo shaft connected to the first recorder shaft, the rotation of the servo shaft thereby being responsive to the rotation of the first recorder shaft;

a second recorder means, comprising;

second recorder drive means constructed and adapted to receive the output return flow-signal from the return flow indicator means and to provide an output drive-signal in response thereto; and

a return-flow indicating means constructed and adapted to receive the output drive-signal from the second recorder drive means and to provide an output flow indication-signal indicative of the drilling-fluid flow through the return flow pipeline;

a remote pit indicating means, comprising;

a shaft rotatingly supported in a portion of the remote pit level indicating means; and

a second servo-control means having an output servo shaft drivingly connected to a portion of the shaft in the remote pit indicating means, the second servo-control means being connected to the first servo-control means so that the second servo means drivingly rotates the shaft in the remote pit indicating means in response to the rotation of the servo shaft of the first servo-control means.

28. The control-monitoring apparatus of claim 27 wherein the remote pit indicating means is further defined to include:

a gear means connected to the shaft of the second servo-control means and to the shaft in the remote pit indicating means, the gear means thereby providing the driving connection therebetween, the gear means being sized to amplify the rotational movement of the servo shaft of the second servo-control means, the incremental degree of rotation of the shaft in the remote pit indicating means being thereby greater than the rotation of the shaft of the first recorder means.

29. The control-monitoring apparatus of claim 28 wherein the remote pit indicating means is further defined to include:

a biasing means supported in the remote pit indicating means, a portion of the biasing means being in biasing engagement with the shaft in the remote pit indicating means, the biasing means being sized and disposed to biasingly maintain the gearing interconnection between the shaft of the second servo-control means and the shaft in the remote pit indicating means; and

wherein the shaft in the remote pit indicating means is further defined as being slidably disposed therein, the gearing interconnection between the shaft of the second servo-control means the shaft of the remote pit indicating means being disconnected by the sliding of the shaft in the remote pit indicating means a predetermined distance against the biasing force of the biasing means, the shaft in the remote pit indicating means being thereby rotatable to a predetermined position.

30. The control-monitoring apparatus of claim 29 wherein the remote pit indicating means is further defined to include:

a dial-indicator secured to one end of the shaft in the remote return flow indicating means, the dial-indicator thereby providing an instantaneous, visual indication of the drilling-fluid level in the fluid-bits at a remote position with respect to the first recorder means.

31. A control-monitoring apparatus adapted to cooperate in a drilling-fluid circulation sytem, comprising:

a fluid-pit for retaining a volume of drilling-fluid;

a pump connected between the fluid-pit means and the borehole pumping drilling-fluid from the fluid-pit means into the borehole in one position thereof;

a return flow pipeline connected between the borehole and the fluid-pit means, some of the drilling-fluid being returned to the fluid-pit means from the borehole via the return flow pipeline;

level indicating means disposed in the fluid-pit and being constructed and adapted to sense the level of the drilling-fluid in the fluid-pit and to provide an output level-signal indicative of the sensed drilling-fluid level;

return flow indicator means connected to the return flow pipeline and being constructed and adapted to indicate the flow of drilling-fluid through the return flow pipeline, and to provide an output return flow-signal indicative of the sensed flow of drilling-fluid, comprising;

a paddle means, having opposite ends, and being disposed in a portion of the return flow pipeline in a position wherein a portion of the paddle means contacts the drilling-fluid flowing in the return flow line, thereby moving the paddle means;

a paddle shaft having a portion thereof secured to one end portion of the paddle means, the movement of the paddle means by the drilling-fluid thereby rotating the paddle shaft;

a return flow transducer housing having a shaft aperture formed through a portion thereof, the shaft aperture sized to rotatingly receive a portion of the paddle shaft extending therethrough;

moisture-seal means connected to a portion of the paddle shaft an to a portion of the return flow transducer housing to provide a moisture-tight seal between paddle shaft and the return flow transducer housing, comprising;

a hollow stationary member, having opposite ends and an outer periphery, one end of the stationary member being sealingly secured to the return flow transducer housing, the hollow portion of the stationary member encompassing the shaft aperture and a portion of the paddle shaft, the paddle shaft being freely rotatable therein;

a lip portion formed on the end of the stationary member opposite the end thereof secured to the return flow transducer housing, the lip portion extending a distance radially from the stationary member about the outer periphery thereof; and

a hollow rotating member, having opposite ends and an inner and an outer periphery, one end of the rotating member being secured to a portion of the paddle shaft, the end of the rotating member, opposite the end thereof secured to the paddle shaft, extending a distance axially over the lip portion of the stationary member;

return flow transducer means supported in the return flow transducer housing and being connected to one end portion of the paddle shaft, the return flow transducer means being constructed and adapted to provide the output return flow-signal in response to the rotational movement of the paddle shaft; and

a drilling-fluid control indication apparatus comprising;

a first recorder means, comprising;

a first recorder drive means constructed and adapted to receive the output level-signal from the level indicating means and to provide an output drive-signal in response thereto;

a pit indicating means constructed and adapted to receive the output drive-signal from the first recorder drive means and to provide an output level indication-signal indicative of the drilling-fluid level in the fluid-pit; and

a second recorder means, comprising;

a second recorder drive means constructed and adapted to receive the output returN flow-signal from the return flow indicator means and to provide an output drive-signal in response thereto; and

a return-flow indicating means constructed and adapted to receive the output drive-signal from the second recorder drive means and to provide an output flow indication-signal indicative of the drilling-fluid flow through the return flow pipeline.

32. A control-monitoring apparatus adapted to cooperate in a drilling-fluid circulating system, comprising:

a fluid-pit for retaining a volume of drilling-fluid;

a pump connected between the fluid-pit means and the borehole pumping drilling-fluid from the fluid-pit means into the borehole in one position thereof;

a return flow pipeline connected between the borehole and the fluid-pit means, some of the drilling-fluid being returned to the fluid-pit means from the borehole via the return flow pipeline;

level indicating means disposed in the fluid-pit and being constructed and adapted to sense the level of the drilling-fluid in the fluid-pit and to provide an output level-signal indicative of the sensed drilling-fluid level;

return flow indicator means connected to the return flow pipeline and being constructed and adapted to indicate the flow of drilling-fluid through the return flow pipeline, and to provide an output return flow-signal indicative of the sensed flow of drilling-fluid; and

a drilling-fluid control indication apparatus, comprising;

a first recorder means, comprising;

a first recorder drive means constructed and adapted to receive the output level-signal from the level indicating means and to provide an output drive-signal in response thereto;

a pit indicating means constructed and adapted to receive the output drive-signal from the first recorder drive means and to provide an output level indication-signal indication of the drilling-fluid level in the fluid-pit; and

a second recorder means, comprising;

a second recorder drive means constructed and adapted to receive the output return flow-signal from the return flow indicator means and to provide an output drive-signal in response thereto; and

a return-flow indicating means constructed and adapted to receive the output drive-signal from the second recorder drive means and to provide an output flow indication-signal indicative of the drilling-fluid flow through the return flow pipeline;

a pump transducer means connected to the pump and being constructed and adapted to provide an output flow-signal indicative of the volume of drilling-fluid being moved through the pump;

a register means constructed and adapted to receive the output flow-signal from the pump transducer means to provide an output volume indication-signal indicative of the volume of drilling-fluid being moved through the pump;

a continuity actuator means interposed between the pump transducer means and the register means and being constructed and adapted to receive the return flow-signal from the pump transducer means, the continuity actuator means having an actuated and a deactuated position, the return flow-signal from the pump transducer means being connected to the register means in an actuated position of the continuity actuator means and the pump transducer means being disconnected from the register means in a deactuated position of the continuity actuator means, comprising;

a relay means having an energized position and a de-energized position, the relay means being connected to the pump transducer means and the register means to establish continuity therebetween in an energized positon of th realy mans, comprising;

a power supply means connected to the relay means to provide energizing power therefor when connected thereto;

a momentary switch means, having a deactuated and an actuated position, the momentary switch means being interposed between the power supply means and relay means, the momentary switch means connecting the and relay means, the momentary switch means conNecting the power supply means to the relay means in an actuated position thereof and disconnecting the power supply means from the relay means in a deactuated position thereof;

a holding relay means, having an energized position and a deenergized position, the holding relay means being connected to the power supply means and to the relay means, in a de-energized position thereof, the relay means being constructed to provide continuity between the relay means and the power supply means via the holding relay means, in an energized position of the relay means and in a de-energized position of the holding relay means, the relay means thereby cooperating with the holding relay means to maintain the relay means energized after the momentary switch means is moved from an actuated to a deactuated position; and

means to energize the relay means in one position thereof.

33. The control-monitoring apparatus of claim 32 wherein the means to de-energize the holding relay means is further defined to include:

a power supply means connected to the holding relay means to provide energizing power therefor when connected thereto;

a zero flow switch means, having an opened and a closed position, and being interposed between the holding relay means and the power supply means, the zero flow switch means connecting the power supply means to the holding relay means in the closed position thereof, and disconnecting the power supply means from the holding relay means in an opened position thereof; and

means connected to the zero flow switch means, and being adapted to receive the output flow indication signal from the return flow indicating means and to close the zero flow switch means when the output flow indication signal indicates drilling-fluid flow in the return flow pipeline.