SU1002508A1 - Drilling rig - Google Patents

Description

and pump 9 with adjustable capacity. The drilling tower 1 is equipped with guides 10, and the crown block 4 is arranged to interact with these guides and is rigidly connected to the rod of the hydraulic cylinder 6, the body of which is connected to the drilling tower 1, the capacity 7 is formed by the case of the hydraulic cylinder 6 and the glass 11. The cavity of the hydraulic cylinder 6, the rod and piston, are connected to each other through the throttle valve 8, the piston cavity is connected to the cavity of the fluidity 7 by making the cylinder body b open from the side of the piston cavity, and the rod cavity is connected to the highway 12 The second pipe 13 is connected to the cavity of the tank 7. The throttle valve 8 and the pump 9 are controlled from the control unit 14 by a command from the limit switches 15 and 16. The traveling block 3 communicates with the pipe pipe 17 via the elevator 18. The installation works as follows. When lowering the tubing string into the well, simultaneously with turning off the winch 2, the control unit 14 is turned on, which gives the command to turn on the pump 9 of variable capacity / which, taking the working fluid from the cavity of the tank, 7, pumps it into the rod end of the hydraulic cylinder 6, causing it the rod, together with the crown block 4, is moved upwards, in the direction opposite to the movement of the descent pulley block 3 with the column pipes. In this case, the throttle valve 8 for covered. As the rod moves upward, the working fluid displaced from the piston cavity of the hydraulic cylinder 6 enters the cavity of the container 7. Thus, the resulting (true) descent rate at the acceleration section (Vpair) consists of two components: the actual descent p. steady speed () according to the set value and the speed of movement of the rod with crown block 4 (VyjT) opposite to it in the direction. For the general case, the speed of the descent of the pipe string at the acceleration site (Fig. 2, Lt. T) can be found from

At the same time, the speed of movement of the rod (Uz), depending on the feed developed by the pump 9 at a predetermined period of time t, takes values from maximum to zero. By

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At the same time, the speed of movement 1 of current (DCR) by throttling the achievement of speed (), close to the value of the steady-state speed (.), The control unit 14 gives a command to shut down the pump 7. The movement of the rod and crown block 4 is stopped. From this point on, the descent of the pipe string is performed at a steady rate (Fig. 2, teach. P). Smooth transition to set speed, i.e. The deceleration process (Fig. 2, Study Ill) starts from the moment the limit switch 16 triggers from contact with the traveling block 3. The control unit 14 again starts the pump 9. Under the effect of the injected fluid into the rod cavity of the hydraulic cylinder 6, the rod together with crown block 4 moves to the extreme upper position, while selecting the full stroke of the hydraulic cylinder 6. The rod movement, as in the acceleration mode, is opposite to the direction of movement of the descending pipe string. The resulting descent speed in the braking section is from an expression similar to (1) with the only difference that the rod speed (Uts) changes vice versa from zero to maximum at the moment the loaded elevator 18 contacts the rotor table VUJT, and then in accordance with expression (2) the speed of descent will be equal to zero. At the same time, the pump 9 and the winch 2 are turned off. When lifting the tubing at the moment of tearing off the loaded elevator 18 from the rotor table, the winch 2 is lifted. At the same time, the control unit 14 gives the command to turn on the throttle valve, which by-passes the working fluid from the piston-cylinder cavity 6 into its rod stock through the container 7. From the moment of turning on the valve 8, the block unit 3 participates in a complex movement. At the same time, the traveling block 3, together with the elevator 18 and the column of pipes 17, moves upward, while the 1UTOK of the hydraulic cylinder 6 with the crown block 4 moves downwards, i.e. in the direction opposite to the movement of the traveling block 3. The resulting speed, in the area during lifting and acceleration (Vragg) when lifting the pipe string, is found from

The working fluid on the time interval tpQir varies from maximum to zero (Fig. 3, Lt. T).

Thus, when O, ie, at the moment of the closure of the dros.sel, the ascent rate reaches a predetermined value.

After lifting the tubing at a given speed over the time interval t ,, f., DuH (Fig. 3, exercise II), the transition to the set speed is made from the moment the limit switch 15 operates from contact with the traveling block 3. At the same time, the control unit 14 Re-turns on the throttle solenoid valve 8, as a result of which the rod, together with the crown block 4, continues to move to the lowest position.

The resulting speed of descent in the area of braking

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At Sourd, the stop of the pipe string is reached, winch 2 and valve 8 are turned on.

The drilling rig enables the descent-ascent of the pipe string according to a given law of velocity change in automatic mode, which eliminates the dynamic loads on the elements of the plant, increasing its reliability.

Claims (2)

1. Author's certificate of the USSR 848574, cl. E 21 19/00, 1979. 2. Author's certificate CSCP № 819299, cl. E 21 19/00, 1979 (prototype) .. flOJl