Fluid flow monitoring system for well drilling operations

Claim 2

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: an electrical transducer connected with and periodically actuated by the pump; a monotonic function generator electrically connected with said transducer; sample and hold circuit means connected with said transducer and said generator for providing a voltage directly proportioned to the time between successive transducer actuations; and reciprocal circuit means connected with the sample and hold circuit means for determining the reciprocal of the voltage from the sample and hold circuit means.

Claim 3

The system defined by claim 1 which further comprises cutoff circuit switch means connected with the generator and the reciprocal circuit means to ground the output of the generator when its generated voltage rises to a higher value than could exist if the pump were running at its slowest rate.

Claim 4

The system defined by claim 1 in which said monotonic function generator is a ramp generatOr.

Claim 5

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: a stroke rate meter actuated by the pump and having a voltage output which is an electrical analogue of the frequency of the pump; multiplier means connected with the stroke rate meter and having a voltage output which is an electrical analogue of the fluid input to the well; an output flow sensor communicating with the fluid output of the well, said sensor having a voltage output which is an electrical analogue of said fluid output; an adjustable gain amplifier connected with the output flow sensor, the gain of such amplifier being adjustable for balancing the output of the output flow sensor and the multiplier means; a differential flow comparator connected with the multiplier means and the adjustable gain amplifier and having an output which is the difference between the output voltages of the adjustable gain amplifier and the multiplier means; indicator means connected with the output of the comparator.

Claim 6

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: a stroke rate meter actuated by the pump and having a voltage output which is an electrical analogue of the frequency of the pump; multiplier means connected with the stroke rate meter and having a voltage output which is an electrical analogue of the fluid input to the well; an output flow sensor communicating with the fluid output of the well, said sensor having a voltage output which is an electrical analogue of said fluid output; an adjustable gain amplifier connected with the output flow sensor, the gain of such amplifier being adjustable for balancing the output of the output flow sensor and the multiplier means; a differential flow comparator connected with the multiplier means and the adjustable gain amplifier and having an output which is the difference between the output voltages of the adjustable gain amplifier and the multiplier means; indicator means connected with the output of the comparator.

Claim 7

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: input flow measuring means connected with the pump for measuring the quantity of fluid pumped into a well, said means producing an electrical output analogue of said flow; output flow measuring means sensing the quantity of fluid discharged from the well and producing an electrical output analogue of said flow; a differential flow comparator connected with said electrical analogue outputs and having an output which is the difference between them; integrator means connected with the differential flow comparator to accumulate differential flow therefrom; indicator means connected with the output of the integrator means.

Claim 8

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: input flow measuring means connected with the pump for measuring the quantity of fluid pumped into a well, said means producing an electrical output analogue of said flow; output flow measuring means sensing the quantity of fluid discharged from the well and producing an electrical output analogue of said flow; a differential flow comparator connected with said electrical analogue outputs and having an output which is the difference between them; integrator means connected with the differential flow comparator to accumulate differential flow therefrom; indicator means connected with the output of the integrator means.

Claim 9

The system defined by claim 5 which further comprises an adjustment means connected with the output flow measuring means for balancing the output thereof with the output of the input flow measuring means.

Claim 10

The system defined by claim 5 in which the integrator means is a capacitor.

Claim 11

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: an electrical transducer connected with and periodically actuated by the pump; latching circuit means connected with said electrical transducer; a stroke counter connected with said latching circuit means; an output flow sensor connected with the latching circuit means and communicating with the fluid output of the well, said sensor having a voltage output which is an electrical analogue of said fluid output; said latching circuit means disconnecting the stroke counter from the electrical transducer when the voltage from the output flow sensor increases responsive to the well filling with fluid.

Claim 12

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: an electrical transducer connected with and periodically actuated by the pump; latching circuit means connected with said electrical transducer; a stroke counter connected with said latching circuit means; an output flow sensor connected with the latching circuit means and communicating with the fluid output of the well, said sensor having a voltage output which is an electrical analogue of said fluid output; said latching circuit means disconnecting the stroke counter from the electrical transducer when the voltage from the output flow sensor increases responsive to the well filling with fluid.

Claim 13

The system defined by claim 4 which comprises: a switch connected with the differential flow comparator; a servomotor connected with the switch and driven in a direction to adjust the output of said second multiplier means to stop the voltage output of said comparator.

Claim 14

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: well input flow sensor to generate an electrical analogue of the fluid input to a well; an output flow sensor communicating with the fluid output of the well, said sensor having a voltage output which is an electrical analogue of said fluid output; multiplier means connected with the output flow sensor, the gain of such multiplier means being adjustable for balancing the output of the output flow sensor; a differential flow comparator connected with the output flow sensor and the multiplier means and having an output which is the difference between the outpUt voltages of the adjustable gain amplifier and the input flow sensor; integrator means connected with the differential flow comparator; signaling means connected with the integrator means to warn of flow imbalance.

Claim 15

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: well input flow sensor to generate an electrical analogue of the fluid input to a well; an output flow sensor communicating with the fluid output of the well, said sensor having a voltage output which is an electrical analogue of said fluid output; multiplier means connected with the output flow sensor, the gain of such multiplier means being adjustable for balancing the output of the output flow sensor; a differential flow comparator connected with the output flow sensor and the multiplier means and having an output which is the difference between the outpUt voltages of the adjustable gain amplifier and the input flow sensor; integrator means connected with the differential flow comparator; signaling means connected with the integrator means to warn of flow imbalance.

Claim 16

The system defined by claim 10 in which the multiplier means is an adjustable gain amplifier.

Claim 17

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: an electrical transducer connected with and periodically actuated by the pump; an arm communicating with the output flow of the well, the position of which is established by the rate of flow; a transducer connected with the arm to produce an electrical analogue of the arm position; a differential flow comparator connected with the transducer and the input flow sensor and having an output which is the difference between the output voltages of the transducer and the input flow sensor; an integrator means connected with the differential flow comparator.

Claim 18

In a fluid flow monitoring system for well drilling operations which utilize a pump to produce well input and output fluid flow, the combination comprising: an electrical transducer connected with and periodically actuated by the pump; an arm communicating with the output flow of the well, the position of which is established by the rate of flow; a transducer connected with the arm to produce an electrical analogue of the arm position; a differential flow comparator connected with the transducer and the input flow sensor and having an output which is the difference between the output voltages of the transducer and the input flow sensor; an integrator means connected with the differential flow comparator.