JP3822947B2 - Anti-recoil control device for riser tensioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention automatically controls the relative speed and position of the upper end of the riser with respect to the drill floor (hereinafter referred to as a drilling ship) when separating the lower end of the riser, and prevents the riser upper end from being pushed up to the drilling ship. The present invention relates to an anti-recoil control device for a riser tensioner that controls timing for fixing to a drilling ship.
[0002]
[Prior art]
In general, when the lower end of the riser joint is cut off when the riser joint is stolen, the deep water drilling riser pulls the upper end of the riser strongly upward by the tensioner, so the riser joint is suddenly accelerated and pushed up to the drilling vessel.
[0003]
In order to prevent this, there is an anti-recoil device that lowers the tensioner tension. In the conventional apparatus, however, the timing for separating the riser joint is relied on human judgment. The reason is that since the drilling vessel moves up and down by waves, the drilling vessel when the riser joint is fixed is predicted by predicting the movement of the drilling vessel and the timing when the riser joint will finally come to the riser fixing position where the upper end of the riser is fixed. This is because the lower end of the riser is separated so that the relative speed between the upper end of the riser and the upper end of the riser becomes small.
[0004]
Conventionally, however, the anti-recoil device is operated by relying on human intuition, so there is a high possibility of mistakes and an accident is likely to occur.
On the other hand, the riser joint control by the conventional anti-recoil device is performed in advance by analyzing the behavior of the riser joint to determine the set value of the control device, which requires a lot of labor and time. It was.
[0005]
[Problems to be solved by the invention]
The present invention has been devised to solve the conventional problems, and an object of the present invention is to provide an anti-recoil control device for a riser tensioner that does not require an analysis of the behavior of the riser joint in advance. There is.
[0006]
[Means for Solving the Problems]
An anti-recoil control device for a riser tensioner according to the invention described in claim 1 includes: (a) a hydraulic sensor for measuring a tensioner tensioning the riser upper end upward; and (b) a relative position of the riser upper end with respect to the hull. By measuring the stroke sensor to be measured, (c) the acceleration sensor for measuring the vertical movement of the hull, and (d) the vertical movement of the hull calculated from the riser top tension measured by the hydraulic sensor and the vertical acceleration of the hull measured by the acceleration sensor. The function to determine the riser joint release timing, the function to send a release signal to the BOP control panel at the determined release timing, and the relative speed of the riser top relative to the hull measured by the stroke sensor to obtain the relative speed by time differentiation. Tensioner so that relative speed is close to zero A control panel having a function of adjusting the control valve, that consists of the features.
[0007]
According to the first aspect of the present invention, the tensioner tension is adjusted so that the relative speed between the excavation ship and the riser upper end when the riser joint is fixed is reduced without performing the riser joint behavior analysis in advance. It is possible to control the riser joint disconnection timing.
An anti-recoil control device for a riser tensioner according to a second aspect of the invention predicts a time from when the lower end of the riser is cut off until the upper end of the riser is fixed to the excavation ship, and further, the riser joint at the time when the riser is fixed It also has a function of adjusting the timing of separation so that the relative speed between the two and the speed of the drilling ship are predicted to be close to zero.
[0008]
According to the second aspect of the present invention, it is possible to easily perform from the lower end separation of the riser joint to the upper end fixing with one button operation.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the riser joint 1 has a riser lower end 2 connected to a BOP 5 installed on the seabed 4 via an LMRP 3, and a riser upper end (telescopic joint outer cylinder upper end) 6 is a telescopic joint 8 attached to a drilling vessel 7. Is attached.
[0010]
The riser upper end 6 is always pulled upward by the tensioner 11. That is, the tensioner 11 is mainly composed of a hydraulic cylinder 12, and includes a wire 17 wound around both the pulley 14 attached to the cylinder portion 13 of the hydraulic cylinder 12 and the pulley 16 attached to the piston rod portion 15. One end is fixed to the cylinder portion 13 and the other end is fixed to the telescopic joint outer cylinder 9 of the telescopic joint 8, while the cylinder portion 13 of the hydraulic cylinder 12 passes through a pipe 19 provided with a control valve 18 to the accumulator 20. The stored hydraulic oil B is provided. High pressure compressed air A acts on the hydraulic oil A in the accumulator 20.
[0011]
On the other hand, a hydraulic pressure sensor 21 is attached to the cylinder portion 13 of the tensioner 11, and a stroke sensor 22 and an acceleration sensor 23 are attached to the excavation ship 7.
The hydraulic pressure of the tensioner 11 measured by the hydraulic sensor 21 is input to the control panel 24. The most important riser upper end tension is obtained by measuring the hydraulic pressure of the cylinder portion 13 of the tensioner 11.
[0012]
The vertical acceleration of the excavation ship 7 measured by the acceleration sensor 23 is input to the control panel 24 and integrated by the control panel 24 to obtain the vertical speed of the excavation ship 7.
The stroke sensor 22 is a non-contact type sensor that measures the stroke of the hydraulic cylinder 12 of the tensioner 11, and the measured value is input to the control panel 24. The relative position between the excavation ship 7 and the riser 1 can be considered by directly measuring the behavior of the telescopic joint 8 formed from the telescopic joint outer cylinder 9 and the telescopic joint inner cylinder 10. It is more realistic to measure the relative position between the excavation ship 7 and the riser joint 1 by measuring the distance that the tensioner wire 17 enters and exits.
[0013]
Further, a strain sensor 25 is attached in the vicinity of the riser lower end 2, and changes in axial stress at the riser lower end 2 are input to the control panel 24 via the BOP control panel 26.
The riser lower end 2 is separated by calculating the separation timing after the control panel 24 predicts (calculates) the vertical movement of the drilling vessel 7 from the tension of the riser upper end 6 and the vertical acceleration of the drilling vessel 7, and the riser joint disconnection signal. This is done by outputting The riser lower end 2 is separated by a signal output from the BOP control panel 26 and is separated at the lower end portion of the LMRP 3 indicated by an arrow a. Although it can be confirmed that a disconnection command has been issued by this disconnection signal, it can be confirmed by a strain sensor or a limit switch 25 provided at the lower end 2 of the riser in order to confirm whether or not the disconnection command has been actually disconnected. Then, the control panel 24 starts the anti-recoil control by the command to disconnect the riser joint by the BOP control panel 26 and the confirmation of the disconnection of the lower end 2 of the riser generated by the disconnection of the riser joint.
[0014]
The movement speed of the riser upper end 6 is obtained by time-differentiating the relative position between the excavation ship 7 and the riser upper end 6 to obtain a relative speed, and adding the speed obtained from the acceleration sensor 23 of the excavation ship 7.
Next, the operation of the anti-recoil control device for the riser tensioner will be described.
[0015]
As shown in FIG. 2, the disconnection command switch is turned on (S1). When the LMRP3 disconnect command signal is issued from the BOP control panel 26 to the control panel 24, the control panel 24 starts control using this signal as an input signal to the anti-recoil device system.
Then, a riser gripping position target is set (S2). When the control panel 24 starts control, the motion data of the excavation ship 7 is read, the motion of the excavation ship 7 is predicted, the optimum position for fixing the riser joint 1 is estimated, and the separation timing is determined.
[0016]
That is, the vertical movement of the drilling ship 7 is predicted (calculated) from the tension of the riser upper end 6 input from the hydraulic sensor 21 and the vertical acceleration of the drilling ship 7 input from the acceleration sensor 23, and then the separation timing is determined (calculated). )
Thereafter, the anti-recoil mode is activated (S3). Then, the operation of the hydraulic control valve 18 of the tensioner 11 is started by the control panel 24.
[0017]
Then, the riser lower end 2 is separated (S4). According to the determined separation timing, a separation signal is sent from the control panel 24 to the BOP control panel 26, and the separation control of the LMRP 3 is performed from the BOP control panel 26.
Then, the disconnection is confirmed (S5). The control panel 24 confirms the disconnection of the LMRP 3 with a signal from the sensor 25.
[0018]
Then, the hydraulic control amount of the tensioner 11 is calculated (S6). Then, the hydraulic pressure of the tensioner 11 is adjusted so that the riser joint 1 rises at the calculated speed. That is, the most important tension of the riser upper end 6 is determined by the hydraulic pressure input from the hydraulic sensor 21, while the relative position of the excavation ship 7 and the riser 1 is determined from the stroke of the hydraulic cylinder 12 of the tensioner 11 input from the stroke sensor 22. Accordingly, the relative position between the excavation ship 7 and the riser joint 1 is time-differentiated to obtain the relative speed between the excavation ship 7 and the riser joint 1, and the control valve 18 of the tensioner 11 is controlled so that the relative speed becomes close to zero. (S7).
[0019]
Then fix the riser tube. If the riser joint 1 rises to the fixed position and the relative speed is equal to or lower than the set value (S8), the latching device is operated to fix the riser joint 1 (S9).
Considering the above control method, it is considered that the riser joint can be disconnected at any time. However, in order to simplify the control program of the control panel 24, the excavation ship 7 moves up and down by waves, and the excavation ship 7 It is desirable that the riser joint 1 is cut off when the wave falls in the wave valley, and the relative speed with respect to the riser joint 1 that rises is controlled to be zero while the excavation ship 7 is going up.
[0020]
【The invention's effect】
As described above, the anti-recoil control device for a riser tensioner according to the invention described in claim 1 includes: (a) a hydraulic sensor that measures the tension of the tensioner that pulls the upper end of the riser upward; and (b) a riser for the hull. It is calculated from the stroke sensor that measures the relative position of the upper end, (c) the acceleration sensor that measures the vertical movement of the hull, and (d) the riser upper tension measured by the hydraulic sensor and the vertical acceleration of the hull measured by the acceleration sensor. The function to determine the riser joint release timing by the vertical movement of the hull, the function to send a release signal to the BOP control panel at the determined release timing, and the relative position of the riser top relative to the hull measured by the stroke sensor by time differentiation Find the speed so that this relative speed is close to zero. Since the control panel has a function of adjusting the control valve of the tensioner, the relative speed between the excavating ship and the riser upper end when the riser joint is fixed is reduced without analyzing the behavior of the riser joint in advance. Thus, the tensioner tension can be adjusted, and the riser disconnection timing can also be controlled.
[0021]
Further, the anti-recoil control device for the riser tensioner according to the invention of claim 2 controls the separation timing of the riser joint, so that the operation from the separation to the fixation can be performed without worrying about the behavior of the riser joint and the movement of the ship. Anyone can easily do this with a single button operation.
[Brief description of the drawings]
FIG. 1 is a schematic view of an anti-recoil control device for a riser tensioner according to the present invention.
FIG. 2 is a diagram showing a control flow of the anti-recoil control device for riser tensioner in FIG. 1;
[Explanation of symbols]
1 Riser joint 6 Riser upper end (telescopic joint outer cylinder upper end)
7 Hull 8 Telescopic joint 9 Telescopic joint outer cylinder 10 Telescopic joint inner cylinder 11 Tensioner 18 Control valve 21 Hydraulic sensor 22 Stroke sensor 23 Acceleration sensor 26 BOP control panel

Claims (2)

(A) a hydraulic sensor that measures the tension of the tensioner that pulls the riser upper end upward; (b) a stroke sensor that measures the relative position of the riser upper end with respect to the hull; and (c) an acceleration sensor that measures the vertical movement of the hull. And (d) a function for determining the riser joint disconnection timing by the hull vertical motion calculated from the riser upper end tension measured by the hydraulic sensor and the hull vertical acceleration measured by the acceleration sensor, and the BOP control panel according to the determined disconnection timing. A function to send a disconnect signal to the hull and a function to obtain a relative speed by differentiating the relative position of the upper end of the riser relative to the hull measured by the stroke sensor, and to adjust the control valve of the tensioner so that this relative speed is close to zero. A riser tensioner consisting of a control panel with Nchirikoiru control device. 2. The anti-recoil control device for a riser tensioner according to claim 1, wherein the separation timing of the riser joint is determined in consideration of the motion of the hull and the response of the riser joint.

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