US3866696A - Method and apparatus for the control of a weight suspended from a floating vessel - Google Patents
Method and apparatus for the control of a weight suspended from a floating vessel Download PDFInfo
- Publication number
- US3866696A US3866696A US373968A US37396873A US3866696A US 3866696 A US3866696 A US 3866696A US 373968 A US373968 A US 373968A US 37396873 A US37396873 A US 37396873A US 3866696 A US3866696 A US 3866696A
- Authority
- US
- United States
- Prior art keywords
- cylinder
- piston
- liquid
- accumulator
- heave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 16
- 238000007667 floating Methods 0.000 title description 9
- 239000007788 liquid Substances 0.000 claims abstract description 126
- 238000005553 drilling Methods 0.000 claims abstract description 47
- 230000009471 action Effects 0.000 claims abstract description 23
- 230000006872 improvement Effects 0.000 claims abstract description 7
- 238000004891 communication Methods 0.000 claims description 24
- 238000006073 displacement reaction Methods 0.000 claims description 20
- 239000012530 fluid Substances 0.000 claims description 11
- 230000007423 decrease Effects 0.000 claims description 10
- 230000003247 decreasing effect Effects 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 4
- 238000012423 maintenance Methods 0.000 claims description 2
- 239000000725 suspension Substances 0.000 abstract description 2
- 230000033001 locomotion Effects 0.000 description 26
- 230000008859 change Effects 0.000 description 12
- 125000004122 cyclic group Chemical group 0.000 description 7
- 230000001174 ascending effect Effects 0.000 description 3
- 230000001351 cycling effect Effects 0.000 description 2
- 238000013016 damping Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 101100181929 Caenorhabditis elegans lin-3 gene Proteins 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000004260 weight control Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
- F15B1/02—Installations or systems with accumulators
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
- E21B19/08—Apparatus for feeding the rods or cables; Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods
- E21B19/09—Apparatus for feeding the rods or cables; Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods specially adapted for drilling underwater formations from a floating support using heave compensators supporting the drill string
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/08—Servomotor systems incorporating electrically operated control means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/2053—Type of pump
- F15B2211/20538—Type of pump constant capacity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
- F15B2211/212—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being accumulators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/21—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge
- F15B2211/216—Systems with pressure sources other than pumps, e.g. with a pyrotechnical charge the pressure sources being pneumatic-to-hydraulic converters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/32—Directional control characterised by the type of actuation
- F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/405—Flow control characterised by the type of flow control means or valve
- F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/42—Flow control characterised by the type of actuation
- F15B2211/426—Flow control characterised by the type of actuation electrically or electronically
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/40—Flow control
- F15B2211/455—Control of flow in the feed line, i.e. meter-in control
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/605—Load sensing circuits
- F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
- F15B2211/6052—Load sensing circuits having valve means between output member and the load sensing circuit using check valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/625—Accumulators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6306—Electronic controllers using input signals representing a pressure
- F15B2211/6309—Electronic controllers using input signals representing a pressure the pressure being a pressure source supply pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6306—Electronic controllers using input signals representing a pressure
- F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a load pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
- F15B2211/7053—Double-acting output members
Definitions
- ABSTRACT The invention concerns the control of the suspended weight from a vessel subject to wave and tidal action and particularly a vessel employed in connection with submarine drilling operation.
- the particular improvement concerns the modulation of the liquid in a hydraulic-pneumatic suspension system subject to heave action so as to maintain the volume of the gas in the accumulator substantially constant during each portion of the cycle action of the heave. This may be ac complished by adding liquid to the accumulator during one portion of the heave cycle and withdrawing liquid from the accumulator during another portion of the heave cycle.
- This invention relates to improvements in methods and apparatus for the control of a suspended weight from a floating vessel and is particularly directed to the control of forces imposed on the drill string of a floating vessel employed in drilling, coring, running casing, reaming, cementing, testing, or other services in bore holes drilled in subaqueous environments where the vessel is subjected to wave or tidal action.
- the particular and preferred object of this invention is to improve the operation of such systems in which the element constituting the load is suspended from a pneumatically controlled hydraulic system.
- the drill string due to the great length above the drill collar, is a very flexible member subjected to considerable stretch due to its length and due to its own weight.
- the weight on the bit is less than the total static weight of the drill string because of the tension in the drill string imposed by the drilling lines as is well understood by those skilled in this art.
- the practice during drilling is to keep the drill pipe above the drill collar in tension.
- the drill collar acts as a weight-producing element which exerts the load on the drill bit.
- Wave action imposes a vertical oscillatory motion on the vessel which is imposed on an hydraulic cylinder resulting in variations in the tension in the drill pipe and therefore in variation in the load imposed upon the drill bit, when this is employed or any other load connected to the piston rod.
- the pressure on the liquid underneath the piston rod is maintained by gas pressure in an accumulator; such systems are shown in the I-Ianes et al., US. Pat. No. 3,7l4,995 and in the Larralde et al. US. Pat. No. 3,7l8,3l6.
- Floating vessels operating as drilling vessels in the open sea may experience vertical motions, i.e., heave due to wave action ranging, for example, from as low as 2 inches to 20 feet or more trough to crest as, for example, has been experienced in drilling of the North Sea.
- the wave action imposes a vertical displacement of the drilling vessel at a substantially sinusoidal frequency. The period of such cycles has been reported in the range of 8 to 16 seconds but may be either greater or less.
- the demand on the string will vary, depending on th services which they are to provide.
- the drill is to be advanced at a controlled rate while maintaining a controlled weight on the bit. It is desirable to maintain a desired upper load limit on the bit in order that excessive stresses and torque are not developed which will be so large as to injure or even cause rupture of the drill pipe. On the other hand, it is desirable that the load on the bit be not reduced excessively so that the rate of advance is unreasonably reduced. Since the cost of operation of the drilling operation is materially affected by the drilling rate, it is desirable that the drilling rate be maintained at as high a rate as is consistent with safety. This is established by the driller based on his experience and the performance of the drilling operation under consideration. The driller sets the load required for' the drilling advance to make the advance be at a satisfactory rate consistent with safety.
- the hydraulic cylinder be mounted on the derrick to support the crown block or between the traveling block and the hook and that a force be applied to the piston sufficient to maintain the desired fraction of the total load of the drill string during drilling operation so as to hold the desired load upon the drill bit.
- the weight which in our presently preferred applications of our invention may be a drill string, is connected as above to the piston of an hydraulic cylinder with the liquid under the piston in communication with a pneumatic accumulator under gas pressure. It is the purpose of our invention to maintain a desired pressure in the cylinder to be main tained during the complete wave cycle so that a predetermined load or a predetermined load variation on the drill can be maintained notwithstanding the amplitude or frequency or changes in the frequency or amplitude of the wave action. Where it is desired that the drill be advanced, our invention will provide a control for the advance of the bit at a desired rate or rate change in addition to the controls during nondrilling conditions.
- FIG. 1 is a somewhat schematic showing of the arrangement of the relations of parts of the system of our invention.
- FIG. 2 is a section of a conventional valve employed in our system.
- FIG. 3 is a schematic diagram of a control system of our invention.
- the motion of the piston with respect to space is a combined motion of the piston due to the heave of the vessel and the advance of the drill during drilling.
- the hydraulic cylinder and piston employed in our invention may be the cylinder and piston design described in the aforementioned patents or any other suitable single or multiple cylinder and piston. We prefer, however, to employ the cylinder and piston described and shown hereinbelow.
- a reference a signal which is proportional to the pressure in the hydraulic cylinder and thus the tensile force on the drill string and the consequent strain on the piston rod and thus to the weight suspended therefrom.
- the magnitude of the signal parameter which is the reference is that which it is desired that the pressure should be during the phase of the operation which it is desired to be controlled.
- the signal which informs our system to add or subtract liquid from the system and the quantity thereof is a deviation of the force signal from the reference signal. If this difference is in a direction indicating that the pressure in the system is falling as a result of a transfer of liquid from the accumulator, our system will supply liquid to reestablish the volume of liquid in the accumulator. If the pressure rises above that at which the reference signal is established, the system will withdraw liquid from the accumulator to re-establish the reference pressure.
- FIG. 1 shows the application of a control of our invention to an operation from a floating vessel 1 acting as the drilling platform.
- the conventional derrick 2 mounted on the vessel carries the split crown block 3 from which the sheaves 5 are suspended by the drilling lines.
- the sheaves 5 carry a cylinder 4, vented at 7, in which is positioned a piston 8 connected to a tubular piston rod 9 from which is suspended the conventional hook 10 which carries a swivel 11 and the kelly 12.
- the drill pipe 14 is connected to the kelly and to the drill pipe which is connected to the bit 15.
- the casing 16 is composed of the conventional marine riser and the bore hole casing assembly together with the usual drilling equipment.
- the hollow piston rod 17 passes through a seal in the piston 8 and carries a piston head 13 connected by a closed-end tube 17 to the cylinder head.
- the tubular member 17 is bored at 6 to provide a communication between the inlet 19 to member 17 and to annulus 18 between the tubular rod and the tubular member 17.
- This cylinder and rod construction and its use as a weight control have been described in the aforesaid application, Ser. No. 274,880.
- the tubular member 17 is connected by a pipe 19 via the solenoid valve 20, to be more fully described below, to the reservoir 21 through valves 22, pump 24, and valve 23. Valves 23 and 22 are solenoid controlled as will be described below.
- the reservoir 21 is also in communication with the accumulator 34 through the valve 27.
- the pump may circulate via line 28 and valve 29.
- valve 34 instead of connecting the accumulator 34 to accumulator 30 via valve 34, we may use instead of 34 a precharged accumulator containing gas at a selected pressure less than the minimum pressure to be attained in operation. Valve 27 may be, but need not be used.
- the orifice is of such character and of such time constant that for the period of the heave and the pressure differences which are effective across the orifice, the pressure in the accumulator 34 remains substantially constant.
- FIG. 2 illustrates a proportional metering valve by which flow proportional to the magnitude and sign of the electric signal is obtained to maintain the liquid in the accumulators 30 and 30a substantially constant.
- a torquing armature 47 is supported by a flexure tube 48 in such a manner that energizing either coil 49 or coil 50 will cause torquing armature 47 to move in a clockwise or counterclockwise direction as viewed in FIG. 2, moving element 51 and deflecting spring 52 with respect to reference pin 53.
- the resultant movement of element 51 with respect to nozzles 54 thus varies pressure in chambers 55 causing valve spool 56 to move in the direction of lower pressure. Movement of spool 56 to the left permits flow from port 57 to chamber 58 and chamber 59 and out through port 60.
- Movement of the valve spool 56 to the right connects flow port 57 with 58 and through 61 to port 62 which are interconnected with 62.
- Feedback shaft 53 engages feedback spring 52 which, in turn, bears on element 51 attenuating the movement of element 51 so that movement of element 51 represents the summation of forces resulting from the relatively elasticity of flexure tube 48, feedback spring 52, and the magnetic flux forces in coil 49 or 50, thus assuring a displacement of valve spool 56 in such a manner to allow flow proportional to the electric signal to coils 49 and 50.
- valve 20 described herein is a well known valve, and no invention is claimed for the valve apart from its use in the combination and for the purpose of our invention.
- Other valves to regulate the direction and magnitude of flow which will function similarly in our invention may be used.
- the pneumatic accumulator 30 is in communication with the cylinder 4 valve 26 being open.
- the line 19 is connected to the port 57.
- the line 31 is connected to the port 60.
- a by-pass 31a connects line 31 to 19 and the accumulator 34 is connected to line 31 via valve 27 and to line 32 via valve 27a.
- Pump pressure is exerted at valve 22.
- the valves 22, shunted by by-pass valve 220, and 23, shunted by by-pass valve 23a, are positioned in lines 31 and 32 intermediate the by-pass valves and 29.
- Line 32 is connected to the port 62 and to the reservoir through valve 23.
- a pressure sensor 40 is mounted on the line connecting accumulator 30 to the cylinder 4 to be responsive to the pressure in the accumulator.
- a pressure sensor 41 is mounted on line 19.
- the stress and pressure sensors are provided with readouts which produce a voltage proportional to the parameters to which they respond.
- FIG. 3 illustrates the servo control of the volume of the liquid in the accumulator. All electrical elements used in the system are conventional, and their selection will be understood by those skilled in the art to which they pertain. Their assembly in combination with the system here described illustrates the preferred embodiment of the control assembly of our invention.
- the output voltage e, of the pressure sensor 36 is compared with the output voltage e of pressure sensor 41 in comparator 42 to give an output proportional to the difference between e, and e
- the voltage output e of the pressure sensor 40 is compared with the voltage output e of sensor 41 to give a voltage porportional to their difference.
- the voltage output e, of the sensor 36 is compared with the voltage output e of the pressure sensor 40 in the comparator 44 to give a signal proportional to the difference in the voltage outputs e and e;,.
- the voltage output e, is compared in comparator 45 with the voltage output e of the sensor 35 to give a signal proportional to the difference in voltage e, and e,.
- the comparator may be any conventional device to give a signal responsive to the difference of two voltages, such as a summation resistance network or a differential amplifier, or a bridge.
- valve 29 The pump 24, with valve 29' and 29 open and valve 22 closed, circulates liquid around the reservoir against the valve 22 to establish the required fluid pressure at the valve 22 sufficient to pass liquid into the hydraulic system on demand.
- the valve 29 is regulated to hold a desired pressure at valve 22. Having established the voltage e, which is the output of the pressure transducer 36, valves 34' and 27 are closed, thus trapping liquid in 34 under the established pressure to act as a fixed reference, if used instead of the orifice herein described.
- valve 29 may be closed and liquid under the desired pressure drawn from an accumulator 24' under requisite gas pressure.
- the accumulator When the accumulator has been sufficiently depleted in liquid, it may be recharged by pump 24 via valve 29a.
- Liquid will be displaced from the cylinder and the annulus to the reservoir.
- annulus and accumulator 30 are equalized and equal to the pressure in the accumulator 30, e, e e and e are all equal, and switches 67 and 68 are opened, and both 49 and 50 are de-energized. Valves 22, 25 and 23 are closed. Spool 56 moves to close ports 60 and 62.
- valve 23 may remain open, switch 68 may be omitted.
- the inputs to the differential amplifier are the outputs e and e and the outputs of the differential amplifier-rectifier are applied, one to the coil 49 and the other to the coil 50.
- the differential tractive effort of 49 and 50 is, therefore, proportional to the respective signs and magnitudes of e and e
- the resultant displacement of the spool 56 is, therefore, proportional to this difference.
- the orifices at ports 65 and 61 will depend on the aforesaid difference.
- the rate of addition or removal of fluid from the annulus and the cylinder is thus made proportional to the demand in order to establish the desired level of forces.
- the system thus withdraws fluid from the system to the reservoir during the period of the heave from the trough to the crest and adds fluid to the system during the period of the heave from the crest to the trough in an amount to maintain the volume of liquid in the accumulator substantially constant.
- the withdrawal or the addition is interrupted when the pressure in the accumulator has reached a predetermined pressure at which the piston is to be supported, and this operation will occur even though the descent of the piston during drilling operation occurs.
- the criterion for the addition or withdrawal of liquid is the deviation of the pressure from a predetermined norm, which is the pressure desired to be maintained under the piston under the conditions which it is sought to maintain the piston.
- the gas pressures are adjusted to either increase or decrease the pressure in 30 and 3021 as desired; and the system will automatically adjust itself to that pressure as will be evident from what has been described above.
- the vessel and the cylinder are subjected to substantially sinusoidal motions which may be out of phase with the piston which is at lesser or greater amplitude, depending on the structure and operation conditions of the system. This will appear from the following:
- y The spacial amplitude of displacement of the cylinder at any part of the wave, for example at the angle 6 of the sinusoidal motion.
- x The spacial amplitude of displacement of the piston at said angle 6, due only to cyclic motion of the cylinder.
- a The maximum displacement of the cylinder i.e., the amplitude of the heave at the crest, which is one-half of the heave.
- the effective area of the piston i.e., the sum of the effective area of the areas a of the piston 8 and b of the piston 13.
- V Volume of the gas in the accumulator when the system is at rest, i.e., when 0 0.
- the piston motion is influenced by damping considerations and moves out of phase with the motion of the cylinder.
- the phase angle d depends on the dynamics of the system.
- the cylinder motion with respect to the space is a cyclic motion such as a sinusoidal motion.
- the spacial displacement of the cylinder at any angle 6 of the sinusoidal motion may be expressed as y A Sin Band
- the spacial displacement of the piston per degree of the cycle at the angle of the cylinder cycle due only to the cyclic action is X A f
- f (6) is a function of the damping and other conditions of the system which may vary from cycle to cycle and even during any cycle and for wave condition, i.e., frequency and amplitude.
- V 0.5 (5 0.05 feet) 2.525 cu. ft.
- the net liquid volume removed per cycle from the hydraulic and pneumatic system is thus 0.1 cu. ft. per cycle to permit the drill to advance 0.2 feet/cycle while maintaining a constant volume of liquid in the pneumatic accumulator.
- this loss is compensated for by adding the leakage volume to the system during the cycling. Since this leakage loss subtracts liquid from the accumulator, it may require a reduction in the withdrawal of fluid or even an addition of fluid during that portion of the cycle when fluid is to be withdrawn from the cycle and an increase in the addition of liquid when fluid is to be added to the pneumatic-hydraulic system.
- the volume change which is required at any angle will be different as the value of 6 changes as will be apparent from what has been said above.
- the actual change in the volume resulting from the cyclic motion of the cylinder and the advance of the piston in space at any angle 0 of the cycle depends upon an unknown factor. This factor is the function of 0 which represents the spacial displacement of the piston due to cyclic action alone, and this depends upon the conditions of the system and other parameters which are known or may be readily ascertained.
- the leakage factor may be an uncertainty.
- the effect on the force on the piston resulting from changes in volume in the accumulator resulting from the spacial advance of the cylinder due to heave, moditied by the drilling advance when this occurs and by leakage losses, when this occurs, is the integral of the effect of these factors on the force exerted on the piston.
- the signal which reports the change is thus an integration of these force changes.
- the volume of liquid displaced in the assumed 30 foot stroke of the piston is cu. feet which at 0.2 feet per cycle pistonadvance will occur after 150 cycles i.e., at the end of 1,500 seconds or about minutes.
- the drilling lines are adjusted to add a stand of drill pipe, the increase in weight is accounted for by adjusting the pressure in the accumulator and the operation is repeated.
- the piston has drilled off each cycle but a small fraction of the cylinder displacement. This is usually the case. Should, however, the drilling rate exceed the heave rate, then it may be that the liquid would have to be withdrawn during the entire period of the heave at a somewhat different rate than during the ascending than the descending portion of the heave as will be apparent to those skilled in the art for what has been said above.
- an apparatus adapted to be mounted on a vessel subjected to heave due to wave action, which apparatus includes a piston and hydraulic cylinder and co-acting pneumatic accumulator system for control of the pressure in the hydraulic cylinder, means for connecting a load to said piston, the improvement which comprises means adapted to pass liquid under pressure from a source of liquid to the accumulator system, during that portion only of the heave when the volume of the liquid in the accumulator tends to decrease, a reservoir, means for withdrawing liquid from the accumulator to saidreservoir during that portion only of the heave when the volume of liquid in the accumulator tends to increase.
- control means for selectively opening communication between the accumulator and said source and selectively closing communication between the accumulator and said reservoir when said first mentioned communication is opened and control means for opening said second mentioned communication and closing said first mentioned communication.
- control means comprising a signal means responsive to the force imposed in said cylinder on the piston during all portions of the heave, said signal means including means to generate a signal responsive to the forces on the said piston, means to generate a signal responsive to the forces predetermined to be maintained on the piston, means to generate an error signal responsive to the differences between said first and second mentioned signals and means to selectively open and selectively close the aforesaid communications responsive to said error signal.
- said means to open and close said valves including means to sense the force on the piston in said cylinder, and said means to acting to open the valve in said pipe connection when the said force is substantially below a predetermined value and said means to open the valve on the pipe connection to said reservoir acting when the force exerted on said piston is substantially above said predetermined value.
- control means comprising a signal means responsive to the forces imposed on the piston in said cylinder, during all portions of the heave, said signal means including means to generate a signal responsive to the forces on the said piston, means to generate a signal responsive to the forces predetermined to be maintained on the piston, means to generate an error signal responsive to the differences between said first and second mentioned signals and means to selectively open and selectively close the aforesaid connection responsive to said error signal.
- said communication means comprising a signal means responsive to the forces imposed on the piston in said cylinder, during all portions of the heave, said signal means including means to generate a signal responsive to the forces in said cylinder, means to generate a signal responsive to the pressure predetermined to be maintained in the cylinder, means to generate an error signal responsive to the differences between said first and secondmentioned signals and means to selectively open and selectively close the aforesaid communications responsive to said error signal.
- said means to open and close said valves including means to sense the force on the piston in said cylinder on said piston, and said means to open the valve in said pipe connection to the said source operative to open said valve when the said sorce is substantially below a predetermined value and means to open the valve on the pipe connection to said reservoir when the force exerted on said piston is substantially above said predetermined value.
- liquid introduction into the accumulator of liquid being in quantity less than the quantity withdrawn, said introduction occurring only during that portion of the heave when said volume in said cylinder is increasing.
- a method of drilling in submarine environment from a vessel subject to heave as a result of wave action which comprises suspending a drill string connected to a drill bit from a cylinder and piston, mounted on drilling lines suspended in a drill derrick, maintaining said piston under pressure from a pneumatic accumulator connected to said cylinder, advancing said drill string into the earth, continuously removing from said cylinder and accumulator during the period of said heave a volume of fluid displaced from said cylinder by the advance of said drill string into the earth while maintaining a substantially constant pressure in said cylinder during said advance and during said heave.
- said maintenance of substantially constant pressure comprising withdrawing liquid from the cylinder to a body of liquid under gas pressure in said accumulator during that portion of the heave when the volume of said cylinder under the piston is decreasing due to the heave and transferring liquid from the said body of liquid to the cylinder when the volume in the cylinder under the piston is increasing and withdrawing from said cylinder and body of liquid, avolume of liquid during each portion of said heave substantially equivalent to the volume of liquid displaced in said cylinder by the said advance, the volume of liquid in said cylinder and said body decreasing with time while maintaining the said pressure substantially constant.
Landscapes
- Engineering & Computer Science (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
Description
Claims (16)
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US373968A US3866696A (en) | 1972-07-25 | 1973-06-27 | Method and apparatus for the control of a weight suspended from a floating vessel |
US378963A US3871622A (en) | 1972-07-25 | 1973-07-13 | Method and apparatus for the control of a weight suspended from a floating vessel |
NL7405465A NL7405465A (en) | 1973-06-27 | 1974-04-23 | |
JP5777174A JPS5418642B2 (en) | 1973-06-27 | 1974-05-22 | |
FR7422070A FR2235299B1 (en) | 1973-06-27 | 1974-06-25 | |
GB2859274A GB1485503A (en) | 1973-06-27 | 1974-06-27 | Method and apparatus for the control of a weight suspended from a floating vessel |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US00274880A US3841607A (en) | 1972-07-25 | 1972-07-25 | Hydraulic motion compensating apparatus |
US373968A US3866696A (en) | 1972-07-25 | 1973-06-27 | Method and apparatus for the control of a weight suspended from a floating vessel |
Publications (1)
Publication Number | Publication Date |
---|---|
US3866696A true US3866696A (en) | 1975-02-18 |
Family
ID=26957137
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US373968A Expired - Lifetime US3866696A (en) | 1972-07-25 | 1973-06-27 | Method and apparatus for the control of a weight suspended from a floating vessel |
Country Status (1)
Country | Link |
---|---|
US (1) | US3866696A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3943868A (en) * | 1974-06-13 | 1976-03-16 | Global Marine Inc. | Heave compensation apparatus for a marine mining vessel |
US4098491A (en) * | 1975-01-09 | 1978-07-04 | Vetco Offshore Industries, Inc. | Methods and apparatus for the control of a suspended weight from a floating vessel |
US6186248B1 (en) * | 1995-12-12 | 2001-02-13 | Boart Longyear Company | Closed loop control system for diamond core drilling |
CN102146775A (en) * | 2011-01-28 | 2011-08-10 | 胜利油田泰峰机电有限责任公司 | Automatic operation system for oil well operation |
CN102900382A (en) * | 2011-07-28 | 2013-01-30 | 吴江市宏亿纺织有限公司 | Hydraulic cathead device |
CN105221085A (en) * | 2015-10-23 | 2016-01-06 | 宝鸡石油机械有限责任公司 | Two half active crown-block heave compensator that floats |
CN109403865A (en) * | 2018-12-20 | 2019-03-01 | 华北科技学院 | Coal-bed gas parameter measuring while drilling method and device |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3208728A (en) * | 1962-11-19 | 1965-09-28 | Exxon Production Research Co | Apparatus for use on floating drilling platforms |
US3687205A (en) * | 1970-10-28 | 1972-08-29 | Gulf Research Development Co | Floating rig motion compensator |
US3714995A (en) * | 1970-09-04 | 1973-02-06 | Vetco Offshore Ind Inc | Motion compensating apparatus |
US3721293A (en) * | 1971-02-16 | 1973-03-20 | Vetco Offshore Ind Inc | Compensating and sensing apparatus for well bore drilling vessels |
US3779135A (en) * | 1971-03-30 | 1973-12-18 | N Sugimura | Air pressure actuator |
US3793835A (en) * | 1972-02-02 | 1974-02-26 | Vetco Offshore Ind Inc | Variable rate hydraulic-pneumatic weight control and compensating apparatus |
-
1973
- 1973-06-27 US US373968A patent/US3866696A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3208728A (en) * | 1962-11-19 | 1965-09-28 | Exxon Production Research Co | Apparatus for use on floating drilling platforms |
US3714995A (en) * | 1970-09-04 | 1973-02-06 | Vetco Offshore Ind Inc | Motion compensating apparatus |
US3687205A (en) * | 1970-10-28 | 1972-08-29 | Gulf Research Development Co | Floating rig motion compensator |
US3721293A (en) * | 1971-02-16 | 1973-03-20 | Vetco Offshore Ind Inc | Compensating and sensing apparatus for well bore drilling vessels |
US3779135A (en) * | 1971-03-30 | 1973-12-18 | N Sugimura | Air pressure actuator |
US3793835A (en) * | 1972-02-02 | 1974-02-26 | Vetco Offshore Ind Inc | Variable rate hydraulic-pneumatic weight control and compensating apparatus |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3943868A (en) * | 1974-06-13 | 1976-03-16 | Global Marine Inc. | Heave compensation apparatus for a marine mining vessel |
US4098491A (en) * | 1975-01-09 | 1978-07-04 | Vetco Offshore Industries, Inc. | Methods and apparatus for the control of a suspended weight from a floating vessel |
US6186248B1 (en) * | 1995-12-12 | 2001-02-13 | Boart Longyear Company | Closed loop control system for diamond core drilling |
CN102146775A (en) * | 2011-01-28 | 2011-08-10 | 胜利油田泰峰机电有限责任公司 | Automatic operation system for oil well operation |
CN102146775B (en) * | 2011-01-28 | 2015-09-16 | 胜利油田泰峰机电有限责任公司 | Automatic operation system for oil well operation |
CN102900382A (en) * | 2011-07-28 | 2013-01-30 | 吴江市宏亿纺织有限公司 | Hydraulic cathead device |
CN105221085A (en) * | 2015-10-23 | 2016-01-06 | 宝鸡石油机械有限责任公司 | Two half active crown-block heave compensator that floats |
CN109403865A (en) * | 2018-12-20 | 2019-03-01 | 华北科技学院 | Coal-bed gas parameter measuring while drilling method and device |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3871622A (en) | Method and apparatus for the control of a weight suspended from a floating vessel | |
US5209302A (en) | Semi-active heave compensation system for marine vessels | |
US3208728A (en) | Apparatus for use on floating drilling platforms | |
US4429748A (en) | Low pressure responsive APR tester valve | |
CA1195237A (en) | Low pressure responsive apr tester valve | |
US4351261A (en) | Riser recoil preventer system | |
US4367981A (en) | Fluid pressure-tensioned slip joint for drilling riser | |
US3793835A (en) | Variable rate hydraulic-pneumatic weight control and compensating apparatus | |
CA1147646A (en) | Drilling fluid bypass for marine riser | |
US3946559A (en) | Heave compensating devices for marine use | |
JPS5948199B2 (en) | Vertical motion compensation device on mining vessels | |
CA1181680A (en) | Deep water riser system for offshore drilling | |
US3718316A (en) | Hydraulic-pneumatic weight control and compensating apparatus | |
AU2013315440A1 (en) | Tachometer for a rotating control device | |
US3866696A (en) | Method and apparatus for the control of a weight suspended from a floating vessel | |
US2964116A (en) | Signaling system | |
IE44504B1 (en) | Heave compensating apparatus | |
US4039177A (en) | Heave compensation apparatus for a marine mining vessel | |
US3917006A (en) | Floorlevel motion compensator | |
US7240737B2 (en) | Direct proportional surface control system for downhole choke | |
US4098491A (en) | Methods and apparatus for the control of a suspended weight from a floating vessel | |
USRE27261E (en) | Stabilized- offshore drilling apparatus | |
US3991837A (en) | Buoyant counterbalancing for drill string | |
US4235021A (en) | Measuring while drilling tool | |
US3373817A (en) | Apparatus for selectively releasing cable-suspended well tools |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: VETCO OFFSHORE, INC. 5740 RALSTON ST.VENTURA,CA.93 Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VETCO INC.;REEL/FRAME:004056/0858 Effective date: 19820922 |
|
AS | Assignment |
Owner name: VETCO OFFSHORE INDUSTRIES, INC., 7135 ARDMORE ROAD Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:VETCO OFFSHORE, INC., A CORP. OF DE.;REEL/FRAME:004572/0533 Effective date: 19860421 |
|
AS | Assignment |
Owner name: VETCO GRAY INC., Free format text: MERGER;ASSIGNORS:GRAY TOOL COMPANY, A TX. CORP. (INTO);VETCO OFFSHORE INDUSTRIES, INC., A CORP. (CHANGED TO);REEL/FRAME:004748/0332 Effective date: 19861217 |
|
AS | Assignment |
Owner name: CITIBANK, N.A., AS AGENT Free format text: SECURITY INTEREST;ASSIGNOR:VETCO GRAY INC.;REEL/FRAME:005211/0237 Effective date: 19891128 |