JPH10311191A - Antirecoil controlling device for riser tensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antirecoil controlling device for riser tensioner without requiring any behavior analysis of a riser joint in advance. SOLUTION: This controlling device is constituted of a control panel 26. The control panel 26 is equipped with hydraulic sensor 21 for measuring tensile force of a tensioner 11 pulling the upper end 6 of a riser, stroke sensor 22 for measuring a relative position of the riser upper end 6 to the hull 7, acceleration sensor 23 for measuring up and down motion of the hull 7 and function for deciding separation timing of a riser joint 1 from up and down motion of the hull calculated from the tensile force of the riser upper end 6 measured by the hydraulic sensor 21 and up and down acceleration of the hull 7 measured by the acceleration sensor 23. Function transmitting a separation signal to the BOP control panel 26 and relative position of the riser upper end 6 to the hull measured by the stroke sensor 22 are timely differentiated to obtain relative speed by decided separation timing, and function for adjusting a control valve 18 of the tensioner 11 is so equipped that the speed reaches zero.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically controls the relative speed and position of the upper end of a riser with respect to a drill floor (hereinafter, referred to as an excavation ship) when a lower end of the riser is separated, and a riser joint pushes up the excavation ship. The present invention relates to an anti-recoil control device for a riser tensioner that controls the timing of fixing the upper end of the riser to the drilling boat while preventing the rise.

[0002]

2. Description of the Related Art Generally, a deep water excavation riser, when the lower end of the riser joint is cut off at the time of expropriation of the riser joint, the upper end of the riser is strongly pulled upward by a tensioner. Thrust up.

In order to prevent this, there is an anti-recoil device for lowering the tensioner tension. However, in the conventional device, the timing of disconnecting the riser joint is performed depending on human judgment. The reason is that the excavation ship moves up and down by the waves, so it predicts the movement of the excavation ship and the timing when the riser joint comes to the riser fixing position that finally fixes the upper end of the riser, and the excavation ship when fixing the riser joint This is because the lower end of the riser is separated so that the relative speed between the riser and the upper end of the riser becomes smaller.

[0004] However, conventionally, since the anti-recoil device is operated by relying on human intuition, there is a great possibility of making a mistake, which is likely to lead to an accident. On the other hand, in the control of the riser joint by the conventional anti-recoil device, the behavior of the riser joint is analyzed in advance to determine the set value of the control device, and the determination requires a great deal of labor and time. I was

[0005]

SUMMARY OF THE INVENTION The present invention has been devised to solve such a conventional problem, and an object of the present invention is to provide a riser which does not require a riser joint behavior analysis in advance. An object of the present invention is to provide an anti-recoil control device for a tensioner.

[0006]

According to the first aspect of the present invention, there is provided an anti-recoil control device for a riser tensioner, comprising: (a) a hydraulic sensor for measuring a tension of a tensioner pulling an upper end of a riser upward; ) A stroke sensor that measures the relative position of the riser top with respect to the hull, (c) an acceleration sensor that measures the vertical motion of the hull, and (d) a vertical acceleration of the hull that is measured by the riser top tension measured by the hydraulic pressure sensor and the acceleration sensor. The function to determine the timing of disconnection of the riser joint by the vertical motion of the hull calculated from the above, the function to send a disconnection signal to the BOP control panel according to the determined disconnection timing, and the relative position of the upper end of the riser with respect to the hull measured by the stroke sensor Differentiate to find the relative speed, and if this relative speed is zero A control panel having a function of adjusting the control valve of the tensioner to be close, characterized by comprising the.

According to the first aspect of the present invention, the tension of the tensioner is set so that the relative speed between the excavation ship and the upper end of the riser when the riser joint is fixed becomes small without performing the behavior analysis of the riser joint in advance. Can be adjusted, and the timing for disconnecting the riser joint can be controlled. The anti-recoil control device for a riser tensioner according to the invention according to claim 2 predicts a time from when the lower end of the riser is separated to when the upper end of the riser is fixed to the drilling vessel, and further, when the riser joint is fixed. It has a function of predicting the speed of the drilling ship and the speed of the drilling ship, and adjusting the disconnection timing so that the relative speed between the two approaches zero.

[0008] According to the second aspect of the present invention, the operation from disconnecting the lower end of the riser joint to fixing the upper end can be easily performed with a single button operation.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a riser joint 1 has a riser lower end 2 connected to a BOP 5 installed on the sea floor 4 via an LMRP 3, and a riser upper end (telescopic joint outer cylinder upper end) 6 has a telescopic joint 8 mounted on an excavation boat 7. Attached to.

The upper end 6 of the riser is constantly pulled upward by the tensioner 11. That is, the tensioner 11 mainly includes the hydraulic cylinder 12, and the cylinder portion 13 of the hydraulic cylinder 12.
A wire 17 wound around both the pulley 14 attached to the piston and the pulley 16 attached to the piston rod portion 15
Is fixed to the cylinder part 13 and the other end is fixed to the telescopic joint outer cylinder 9 of the telescopic joint 8, while the cylinder part 13 of the hydraulic cylinder 12 is passed through a pipe 19 provided with a control valve 18 and the accumulator 20. The hydraulic oil B stored in the tank is supplied. Hydraulic oil A in accumulator 20
, High-pressure compressed air A is acting.

On the other hand, the cylinder 1 of the tensioner 11
A hydraulic sensor 21 is attached to 3, and a stroke sensor 22 and an acceleration sensor 23 are attached to the excavation boat 7. The oil pressure of the tensioner 11 measured by the oil pressure sensor 21 is input to the control panel 24. The most important riser upper end tension is determined by measuring the hydraulic pressure of the cylinder portion 13 of the tensioner 11.

The vertical acceleration of the drilling boat 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 drilling boat 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. Drilling boat 7
The relative position between the telescopic joint 8 and the telescopic joint 8 formed by the telescopic joint outer cylinder 9 and the telescopic joint inner cylinder 10 may be directly measured by the stroke sensor 22. It is more realistic to measure the relative position between the excavation boat 7 and the riser joint 1 by measuring the distance at which the 17 comes in and out.

Further, a strain sensor 25 is attached near the lower end 2 of the riser, and a change in the axial stress of the lower end 2 of the riser is controlled by the control panel 24 via a BOP control panel 26.
Is entered. To separate the lower end 2 of the riser, the control panel 24 predicts (calculates) the vertical movement of the excavator 7 based on the tension of the upper end 6 of the riser and the vertical acceleration of the excavator 7, and then calculates the timing of disconnection. Is output. The lower end of the riser 2 is separated from the BOP control panel 2
6 is performed by the signal output from the LM shown in FIG.
It is cut off at the lower end of RP3. Although it can be confirmed from the disconnection signal that a disconnection command has been issued, it can be confirmed by a strain sensor or limit switch 25 provided at the lower end 2 of the riser that the disconnection has been truly performed. Then, the control panel 24 starts the anti-recoil control in response to the riser joint separation command signal from the BOP control panel 26 and the confirmation of the separation of the riser lower end 2 caused by the separation of the riser joint.

The movement speed of the riser upper end 6 is obtained by differentiating the relative position between the excavation ship 7 and the riser upper end 6 with respect to time to obtain a relative speed, and adding the obtained speed to the speed obtained from the acceleration sensor 23 of the excavation ship 7. Next, the operation of the above-described anti-recoil control device for riser tensioner will be described.

As shown in FIG. 2, the disconnection command switch is turned on (S1). When a disconnection command signal for the LMRP 3 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 grip position target is set (S2). Control panel 24
Starts the control, reads the motion data of the drilling boat 7, predicts the motion of the drilling boat 7, and sets the riser joint 1
Estimate the optimal position to fix the, and determine the timing of separation.

That is, the vertical movement of the drilling boat 7 is predicted (calculated) from the tension at the upper end 6 of the riser input from the hydraulic pressure sensor 21 and the vertical acceleration of the drilling boat 7 input from the acceleration sensor 23, and the timing of disconnection is determined. Decide (calculate). 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.

Then, the riser lower end 2 is separated (S4). A disconnection signal is sent from the control panel 24 to the BOP control panel 26 according to the determined disconnection timing, and the BOP control panel 26 performs the disconnection control of the LMRP 3. Then, confirmation of disconnection is performed (S5). The control panel 24 confirms disconnection of the LMRP 3 based on a signal from the sensor 25.

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, while the most important tension of the riser upper end 6 is determined by the hydraulic pressure input from the hydraulic pressure sensor 21, the relative position between the excavation boat 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. Therefore, the relative position between the drilling boat 7 and the riser joint 1 is differentiated with respect to time to obtain the relative speed between the drilling boat 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).

Then, the riser tube is fixed. When the riser joint 1 rises to the fixing 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.
In order to simplify the control program of 4, the excavation ship 7 moves up and down by the wave, the riser joint 1 is separated when the excavation ship 7 falls in the valley of the wave, and the excavation ship 7 rises while It is desirable to control the relative velocity with the riser joint 1 to be zero.

[0020]

As described above, the anti-recoil control device for a riser tensioner according to the first aspect of the present invention comprises: (a) a hydraulic sensor for measuring a tension of a tensioner pulling an upper end of a riser upward; b) a stroke sensor for measuring the relative position of the riser upper end with respect to the hull; (c) an acceleration sensor for measuring the vertical movement of the hull; and (d) a rise and fall of the hull measured by the hydraulic sensor for the riser upper end tension and the acceleration sensor. The function of determining the riser joint disconnection timing based on the hull vertical motion calculated from the acceleration, the function of sending a disconnection signal to the BOP control panel based on the determined disconnection timing, and the relative position of the riser top relative to the hull measured by the stroke sensor The relative speed is also obtained by time differentiation, and this relative speed is zero. And a control panel having a function of adjusting the control valve of the tensioner so as to be close to each other, so that the relative position between the excavation ship and the upper end of the riser when the riser joint is fixed without performing a riser joint behavior analysis in advance. The tension of the tensioner can be adjusted so as to reduce the speed, and the timing of disconnection of the riser can be controlled.

The anti-recoil control device for a riser tensioner according to the second aspect of the present invention controls the timing for separating the riser joint, so that it is fixed from the separation without worrying about the behavior of the riser joint or the motion of the ship. Anyone can easily perform the operations up to one button operation.

[Brief description of the drawings]

FIG. 1 is a schematic diagram 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 an anti-recoil control device for a riser tensioner of FIG. 1;

[Explanation of symbols]

Reference Signs List 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 Oil pressure sensor 22 Stroke sensor 23 Acceleration sensor 26 BOP control panel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nariki Ishida 1 Yawata Kaigandori, Ichihara-shi, Chiba Mitsui Engineering & Shipbuilding Co., Ltd. Chiba Works Co., Ltd.

Claims (2)

[Claims] (A) a hydraulic sensor for measuring the tension of a tensioner pulling an upper end of a riser upward;
(B) a stroke sensor that measures the relative position of the upper end of the riser with respect to the hull; (c) an acceleration sensor that measures the vertical movement of the hull; and (d) a hull that measures the riser top tension measured by the hydraulic pressure sensor and the acceleration sensor. The function to determine the disconnection timing of the riser joint by the vertical motion of the hull calculated from the vertical acceleration, the function to send a disconnection signal to the BOP control panel according to the determined disconnection timing, and the relative position of the riser top with respect to the hull measured by the stroke sensor And a control panel having a function of adjusting a control valve of the tensioner so that the relative speed is close to zero. 2. The anti-recoil control device for a riser tensioner according to claim 1, wherein the timing for separating the riser joint is determined in consideration of the motion of the hull and the response of the riser joint.