Control of well fluid level

Claim 2

In a system to automatically adjust the pumping of a well to control the actual level of production fluid freely standing in the well and above the pump, the combination with a reversible main drive the output displacement of which effects vertical stroking of a sub-surface well pump and of a rod string extending from the well head to the pump, of: a. first control means for reversing the main drive at predetermined limits corresponding to upper and lower limits of the well pump stroke, and b. second control means for controlling the rate of said displacement of the main drive in response to changes in said actual level in the well from a predetermined level by increasing the rate of said displacement of the main drive in response to rising of said actual level above said predetermined level, and decreasing the rate of said displacement of the main drive in response to dropping of said actual level, below said predetermined level, said main drive and said second control means located at the well head.

Claim 3

The combination of claim 1 wherein Said main drive includes a reversible hydraulic motor and supply means to supply hydraulic fluid to the motor at a rate controlled by said second means and characterized in that the supply rate increases as said actual level increases, and the supply rate decreases as said actual level decreases.

Claim 4

In a system to automatically adjust the pumping of a well to control the actual level of production fluid in the well, the combination with a reversible main drive the output displacement of which effects vertically stroking of a sub-surface well pump of: a. first control means for reversing the main drive at predetermined limits corresponding to upper and lower limits of the well pump stroke, and b. second control means for controlling the rate of said displacement of the main drive in response to changes in said actual level in the well from a predetermined level, c. said main drive including a reversible motor, and supply means to supply hydraulic fluid to the motor at a rate controlled by said second means and characterized in that the supply rate increases as said actual level increases and the supply rate decreases as said actual level decreases, and d. said first control means including a flow regulator movable to proportionally control the rate of hydraulic fluid supply to the motor via said supply means, and said second control means controlling the extent of movement of the regulator.

Claim 5

In a system to automatically adjust the pumping of a well to control the actual level of production fluid in the well, the combination with a reversible main drive the output displacement of which effects vertically stroking of a sub-surface well pump of: a. first control means for reversing the main drive at predetermined limits corresponding to upper and lower limits of the well pump stroke, and b. second control means for controlling the rate of said displacement of the main drive in response to changes in said actual level in the well from a predetermined level, c. said main drive including a reversible motor, and supply means to supply hydraulic fluid to the motor at a rate controlled by said second means and characterized in that the supply rate increases as said actual level increases and the supply rate decreases as said actual level decreases, and d. said first control means including a flow regulator movable to proportionally control the rate of hydraulic fluid supply to the motor via said supply means, and said second control means controlling the extent of movement of the regulator.

Claim 6

The combination of claim 3 wherein said first control means includes a first actuator, and said second control means includes an adjustable limiter to limit movement of the flow regulator, a second actuator to adjust the limiter, and means to supply fluid pressure to the second actuator in correspondence to the pressure of said hydraulic fluid supply to the motor.

Claim 7

The combination of claim 1 including a counterbalancing assembly connected with the main drive to counterbalance the weight imposed on the main drive by the well pump, the drive connection to the pump, and production fluid in the well.

Claim 8

The combination of claim 4 wherein said means to supply fluid pressure to the second actuator includes a pressure line to receive the pressure of hydraulic fluid supply to the motor, and structure synchronized with the operation of the main drive to sample the pressure in said line when the well pump is stroking upwardly.

Claim 9

The combination of claim 6 wherein said structure comprises a rotor reversibly driven in synchronism with said main drive, and a pressure gating valve in said line and operated in response to turning of the rotor.

Claim 10

The combination of claim 3 wherein said first control means includes a first reversible actuator to move the regulator, ducting to supply auxiliary fluid pressure to the first reversible actuator, and a reversible valve operable in synchronism with the operation of the main drive control to control auxiliary fluid pressure supply to the first actuator for reversing the displacement thereof.

Claim 11

The combination of claim 8 wherein the first control means includes a rotor driven in opposite directions in synchronism with the main drive, and adjustable means to control reversing of the valve in response to rotation of the rotor.

Claim 12

The combination of claim 9 wherein said adjustable means comprises pins carried by the rotor for position adjustment thereon.

Claim 13

The combination of claim 3 including means to supply to the second control means the pressure of hydraulic fluid supply to the motor in either of two lines, corresponding to forward and reverse drive of the motor.

Claim 14

In a system to automatically adjust the pumping of a well to control the actual level of production fluid freely standing in the well and above the pump, the combination with a reversible main drive the output displacement of which effects vertical stroking of a sub-surface well pump of: a. first control means for reversing the main drive at predetermined limits corresponding to upper and lower limits of the well pump stroke, and b. second control means for controlling the rate of said displacement of the main drive in response to changes in said actual level in the well from a predetermined level by increasing the rate of said displacement of the main drive in response to rising of said actual level, and decreasing the rate of said displacement of the main drive in response to dropping of said actual level, c. there being counterbalancing structure near the well surface which counterbalances weight exerted by a column of fluid pumped upwardly in the well by said pump, the amount of counterbalance remaining fixed during operation of said first and second control means, for establishing said predetermined level.

Claim 15

In a system to automatically adjust the pumping of a well to control the actual level of production fluid freely standing in the well and above the pump, the combination with a reversible main drive the output displacement of which effects vertical stroking of a sub-surface well pump of: a. first control means for reversing the main drive at predetermined limits corresponding to upper and lower limits of the well pump stroke, and b. second control means for controlling the rate of said displacement of the main drive in response to changes in said actual level in the well from a predetermined level by increasing the rate of said displacement of the main drive in response to rising of said actual level, and decreasing the rate of said displacement of the main drive in response to dropping of said actual level, c. there being counterbalancing structure near the well surface which counterbalances weight exerted by a column of fluid pumped upwardly in the well by said pump, the amount of counterbalance remaining fixed during operation of said first and second control means, for establishing said predetermined level.

Claim 16

In a system to automatically adjust the pumping of a well to control the actual level of production fluid freely standing in the well and above a pump being vertically stroked, the improvement which comprises a. means responsive to the fluid level in the well to control the rate of pumping of the well by controlling the vertical speed of said stroking so as to maintain said actual level near a predetermined level, and b. means for controlling the length of said stroking.

Claim 17

In a system to automatically adjust the pumping of a well to control the actual level of production fluid freely standing in the well and above a pump being vertically stroked, the improvement which comprises a. means responsive to the fluid level in the well to control the rate of pumping of the well by controlling the vertical speed of said stroking so as to maintain said actual level near a predetermined level, and b. means for controlling the length of said stroking.

Claim 18

The system of claim 13 wherein the system includes pumping structure movable up and down in the well, and counterbalancing structure near the well surface counterbalancing the weight of said pumping structure and a column of well fluid pumped upwardly in the well by said pumping structure.

Claim 19

In the method of adjusting the pumping of a well to control the actual level of production fluid freely standing in the well and above a pump and rod string being vertically stroked, the steps that include a. sensing, at the surface of the well, the well pumping requirements as imposed by the actual level of fluid in the well, and b. controlling the rate of pumping by controlling the vertical speed of said stroking at the well head and in response to such sensing thereby to increase said speed in response to rising of said active level above a predetermined level and to decrease said speed in response to dropping of said actual level below said predetermined level so as to maintain said actual level near said predetermined level.

Claim 20

In the method of adjusting the pumping of a well to control the actual level of production fluid freely standing in the well and above a pump and rod string being vertically stroked, the steps that include a. sensing, at the surface of the well, the well pumping requirements as imposed by the actual level of fluid in the well, and b. controlling the rate of pumping by controlling the vertical speed of said stroking at the well head and in response to such sensing thereby to increase said speed in response to rising of said active level above a predetermined level and to decrease said speed in response to dropping of said actual level below said predetermined level so as to maintain said actual level near said predetermined level.