US3895677A

US3895677A - Riser pipe stacking method

Info

Publication number: US3895677A
Application number: US434651A
Authority: US
Inventors: Donald G Bokenkamp
Original assignee: DOLPHIN INTERNATIONAL Inc
Current assignee: DOLPHIN INTERNATIONAL Inc
Priority date: 1974-01-18
Filing date: 1974-01-18
Publication date: 1975-07-22
Anticipated expiration: 1992-07-22
Also published as: NO742065L; GB1452702A; CA1002933A

Abstract

An offshore drilling rig that embodies a means for vertical stacking of riser pipe sections and blowout preventors below a derrick floor and includes riser pipe manipulating mechanisms for transporting units in a vertical condition between a storage area and the operational area. In the operational area, the cellar floor is provided with a sliding door mechanism which is selectively capable of supporting either the blowout preventor and riser weight, or the blowout preventor. The transportation system includes means for lifting and supporting a riser pipe section vertically and movable in transverse and longitudinal, horizontal directions for transporting pipe sections in a vertical condition.

Description

United States Patent [191 [111 3,895,677

Bokenkamp 1 July 22, 197 5 1 RISER PIPE STACKING METHOD 3,333,562 8/1967 Deal et al. 114/.5 n

t D ld G. B kenka Houston,

[75] Inven or 'l it 0 mp Primary Examiner-Ernest R. Purser [73] Assignee: Dolphin International, Inc., I ABSTRACT Houston, Tex. An offshore drilling rig that embodies a means for ver- [22] Filed 1974 tical stacking of riser pipe sections and blowout pre- [21] Appl. No.: 434,651 ventors below a derrick floor and includes riser pipe manipulating mechanisms for transporting units in a vertical condition between a storage area and the op- [52] 166/5; 166/315; 47 erational area. In the operational area. the cellar floor is provided with a sliding door mechanism which is se- [51] CLZ E21B 19/14 lectively capable of supporting either the blowout pre- Field of Search 166/ 5 315 175/5 ventor and riser weight, or the blowout preventor. The

transportation system includes means for lifting and supporting a riser pipe section vertically and movable in transverse and longitudinal, horizontal directions [56] References Cited for transporting pipe sections in a vertical condition.

UNITED STATES PATENTS 3,043,255 7/1962 Bauer et al. 114/.5 D 4 Clams 8 Draw 3,189,093 6/1965 De Vries 166/.5

PATENTEDJUL22 1315 3.895577 SHEET 2 FIG. 2 20 19A FIG. 3

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PATENTEDJUL 22 I975 3,895,677 SHEET 3 squ 5pc 50 40 =1 l I I I I lli I x!" I .m'

pi I mil FIGS RISER PIPE STACKING METHOD BACKGROUND OF THE INVENTION dition below the derrick floor and for transporting such units in vertical condition between storage and operational areas.

In offshore drilling rigs, it is customary to have a string of interconnected tubular pipe sections extending from the rig to a blowout preventor means (sometimes hereinafter referred to as BOP) set on the ocean floor. The drilling string is then inserted through the tubular pipe string (called a riser) for the drilling of the earth formations below the ocean floor.

On most rigs during the installation or removal of a riser pipe system, the riser is set or supported dependently on the rotary table and connections of riser pipe sections are made at the rig or derrick floor level. When not in use, the lengths of riser pipe sections are usually passed through a V-door and supported horizontally on a pipe rack by means of a rig crane. This manipulation of riser pipe sections between a horizontal position on a pipe rack and a vertical passage through the rotary table is similar to the operation required for running casing strings. The operation requires virtually the full drilling crew as well as crane operators and roustabouts.

During rough weather, the riser sections are hard to control while hanging on the crane-sling lines. Tag lines are an aid but the chance for injury to personnel or damage to the riser is great. Actually, the problem of retrieving riser sections often comes about because of bad weather where it is desired to pull the riser string.

In the present invention, enough clearance is provided between a lower cellar deck and the derrick floor to rack or store the riser sections vertically under the derrick floor. The advantages of this concept include:

I. The need to lay down the riser pipe joints on the pipe rack is eliminated;

2. Wind or dynamic loading on the derrick is not increased as it would be if the riser were racked in the derrick;

3. More pipe rack area is available for other tubulars;

4. The hazard to equipment and personnel created by frequent crane handling is eliminated;

5. The same storage area is used for transit that is used while pulling or running;

6. The number of personnel required to handle the riser is reduced;

7. The time necessary to run or pull the riser is decreased; and

8. The capability for handling the riser in more severe weather is increased.

SUMMARY OF THE INVENTION floor to the riser storage area. In this regard, the transportation system has capability for transverse and longitudinal, horizontal directional movement and vertical lifting movement. Means are provided for independent motion in any of the three coordinate directions. The transportation means include a bridge type crane mounted for movement on a pair of rails. A vertical lifting device is mounted for sliding movement along a transverse beam of the crane. At the cellar floor opening is a first pair of supporting arms for engaging and supporting blowout preventors where the supporting arms are spaced at appropriate distances relative to blowout preventors sizes. At the cellar floor opening also is a second pair of supporting arms for engaging and supporting riser pipe sections. The separate pair of supporting arms utilize the same space but can be selectively employed.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more apparent when the following description is taken in connection with the drawings in which:

FIG. 1 is a schematic representation of an offshore rig embodying the riser pipe handling system of the present invention;

FIGS. 24 are plan views of the door and opening in extended and retracted positions;

FIG. 5 is a view taken along line 5-5 of FIG. 3;

FIG. 6 is a side view taken along line 66 of FIG. 7;

FIG. 7 is a plan view of the transporting system for riser pipe and BOP means; and

FIG. 8 is a schematic illustration of the cellar floor plan for transporting and storing riser pipe sections.

DESCRIPTION OF THE INVENTION Referring now to FIG. 1, an offshore rig or drilling barge 10 which can be a semi-submersible which supports a drilling floor 11 above the surface 12 of the ocean 13. Below the drilling floor 11 is a cellar deck or floor 14. The clearance between the cellar floor 14 and drilling floor 11 is made adequate to permit vertical stacking of riser pipe sections between the two floors l1 and 14. On the drilling floor I1 is a derrick l5 equipped with a traveling block 16, draw works 17, and a rotary table 18. Vertically aligned with the rotary table 18 is an opening 19 (sometimes called a moon pool opening) in the cellar floor 14. A special two-stage horizontally movable door 20 is movable between an extended position over the opening to support selectively either a riser pipe section or a Blow Out Preventor (hereinafter referred to as BOP). The door 20 is powered by suitable hydraulic or mechanical means which is schematically illustrated by the numeral 21. The door powering means 21 is capable of horizontally reciprocating the door 20 relative to the opening 19 between an extended position over the opening or a retracted position where the opening is entirely clear. As illustrated in FIG. 1, a riser pipe string 22 is extended from the cellar floor 14 to the ocean floor 23. The riser string 22 is comprised of the usual tubular riser pipe sections or joints which are connected to one another. At the bottom of the riser string is a BOP means 24 which attaches to the ocean floor well head connection. The BOP means 24, as illustrated, has an enlarged cross-section as compared to the cross-section of a riser pipe section. The vertical clearance between the cellar floor and derrick floor is such that one of the riser pipe sections 25 can be vertically disposed in the clearance between the rotary table 18 in the drilling floor and opening 19 in the cellar floor. The riser pipe sections and BOP means have support means (to be explained later) which are engagable by the door 20 to support the riser string 22 while a riser pipe section 25 is added or subtracted from the riser pipe string.

Means for moving a riser pipe section in the space between the drilling rig floor and cellar floor include a bridge crane 27 which is mounted for movement in one horizontal direction by spaced apart guide rails 28 (only one shown). The crane includes wire lines 29 for moving the BOP means vertically with respect to the cellar floor. A transverse beam 30 on the bridge crane extends between the guide rails 28. A fork lift type device 31 is mounted for movement along the length of the beam 30 and is also capable of vertical movement relative to the transverse beam 30. The purpose of this arrangement is to transport riser pipe sections or BOP means in a vertical condition between the cellar opening 19 and storage areas. The storage area for the BOP means is to either side of the opening as shown by the illustration of upper and lower BOP stacks 32 and 33. The storage area for the riser pipe sections includes upper fingers 35 which are arranged to receive the upper portion of the riser pipe sections and stubs 36 set along the cellar floor for receiving the open lower end of each riser pipe section.

In the overall operation of the system, the crane 2 first picks up the lower section 33 of a BOP and moves it to the opening 19. The BOP portion 33 is lowered partially through the opening with the door 20 in a retracted condition. Then, the door 20 which has beams for supporting the BOP 33, is moved to an extended position where the door arms support the BOP portion 33 relative to the cellar floor. The bridge crane 27 is then used to move the upper BOP section 32 over the lower section and the BOP sections are connected. After connection of the upper BOP section 32 to the lower BOP section 33, a single joint of riser pipe that has been prepositioned on the hook of the traveling block 16 by means of a running too] (not shown) is lowered through the rotary table 18 and connected to the top of the assembled BOP stack. The BOP stack is then picked up sufficiently for clearance and the sliding door 20 is retracted to allow passage through the cellar deck opening 19 of the BOP. After the BOP has been sufficiently lowered to clear the cellar deck opening 19, a second pair of door arms are engaged to the first set of door arms that previously supported the BOPs. The interconnection of the two sets of arms is accomplished while the door is in the retracted position. The door 20 is then manipulated again to an extended position with the now interconnected second set of arms that are spaced apart sufficiently to provide clearance for the riser and to support a riser spider 37 which will support the riser section and BOP connected to it. The riser spider 37 is then installed around the riser and supported by the second set of arms. The riser is then set in it. The running tool (not shown) is then released and pulled up sufficiently to provide clearance for the next joint of riser. The fork lift device 31 is moved to the riser pipe section storage area and another riser pipe section is picked up vertically and transported in a vertical condition to the cellar opening 19 where it is lowered and coupled to the riser joint setting in the riser spider. The running tool (not shown) attached to the traveling block 16 is lowered through the rotary table 18 to attach to the connected riser pipe section. After connection with the running tool, the assembled stack is picked up sufficiently to release the spider and then is lowered until the second riser pipe section is in position to be supported by the riser spider 37. This sequence is repeated for the other riser pipe sections as needed. The operation is reversed for pulling the riser string.

Referring now to FIGS. 2-5, the door 20 and opening 19 are shown in greater detail. The opening 19 is defined by a rectangular shaped frame comprised of frame components 19(A-D) which attach to the cellar floor. The side frame components or members 19a and are elongated and attached to an end frame member 1%. In FIG. 2, the door 20 is in a retracted position and rests upon the frame members 19c, 19a, 19c and 19d. The door 20 includes two sets of generally U- shaped gate members. A first U-shaped member 40 is shown most clearly in FIG. 3. The gate member 40 has a length greater than the span between the frame members 19d and 19c, and its open end lies on the transverse frame member 19d in the retracted position of the gate member. The U-shaped gate member 40 includes a pair of longitudinally extending bar members 40a and 40b which are spaced apart a distance compatable with the outer diameter of a riser pipe section so that ariser pipe section can be supported by a riser spider installed on the gate member 40. For supporting riser pipe sections, a conventional riser pipe spider is also employed but is not shown for clarity of illustration.

The other U-shaped gate member 50 is also shown most clearly in FIG. 3. The gate member 50 has its open end facing the opening 19 where the open end is defined by parallel bar members 50a and 50b. The bar members 50a and 50b are spaced apart a distance compatable with the outer diameter of a BOP. The bar members 50a and 50b attach toa pair of spaced transverse bars 50c and 50d which extend across the width of the frame member 19d. Side support bar members 50c and 50f extend along the length of the frame members 29a and 19c and attach to the BOP supporting bars 50a and 50b. As illustrated in FIGS. 2 and 3, the gate member 50 is movable between a retracted and extended position relative to the cellar opening 19. Mean (such as tongue and groove connections not shown) are provided for suitable guiding of the gate members relative to the frame. The gate member 50 has its transverse members 50c and 50d disposed above the bars 40a and 40b (see FIG. 5) of the gate member 40 so that the

gate members

40 and 50 may move horizontally between retracted and extended positions independently of one another. Selective locking means in the form of openings 40c and 50g are respectively provided in the bars 40a and 40b and the transverse bars 50c and 50d. Pins (not shown) are used to couple the gate members to one another. Hence, as shown in FIG. 4, both

gate members

40 and 50 can be retracted and extended relative to the opening 19 in unison.

A riser spider 37 is conventional and is shown schematically in FIG. 4. The spider 37 includes hinged semi-cylindrical members with four equidistantly spaced latching fingers-37a. The latching fingers 37a releasably engage latching slots in a riser section for plan view. The guide rails 28 are spaced from one another in a parallel fashion at the height above the cellar floor adequate to permit transportation of a riser pipe section in a vertical condition. Elongated

end frame members

61 and 62 extend along the rails and carry journaled pairs of wheels 63. The

frame members

61 and 62 are connected to

transverse beam members

64 and 65 which can have box type cross-sections. The frame and

beam members

61, 62, 64 and 65 form a generally rectangular configuration which is movable in a horizontal direction by virtue of the wheels 63 and the track 28. A longitudinal rack 66 can be attached to one or both of the rails 28. A pinion 67 on the wheel shaft 68 engages the rack 66 for driving purposes. A motor and transmission means'69 on the beam 64 can be used to drive the shaft 68. As shown in FIG. 6, one or more hooks 29 attached to cable and spooling means 70 can be provided on the frame for picking up equipment such as the BOP means.

On the forward transverse beam 65, its upper and lower surfaces are provided with longitudinally extending

guides

71, 72 and 73. A U-shaped frame member 74 has an upper arm with a vertically journaled set of rollers 75 which engage a side of the guide 71 facing away from the front of the beam 65. Horizontally journaled sets of rollers76 in the frame 74 engage the upper surfaces of the

guides

71 and 73. A vertically journaled roller in the lower arm of the frame member 74 engages an outer side of the lower guide 72. The guides and rollers provide a cantilevered rolling support for the frame member 74 on the transverse beam 65. A motor 77 on the frame member operates a pinion on the frame member 74 which engages a longitudinal rack 78 on the beam 65. Operation of the motor 77 traverses the frame member 74'relative to the beam member 65 in a horizontal direction transverse or perpendicular to the direction of travel of the beam member 65 on the rails 28.

The foward portion of the frame member 75 is provided with parallel vertical trackways 80 in opposing sides of the frame member. Guide rollers 81 are received in the guideways and are attached to a lifting frame 82. Additional side rollers 83 are provided so that the lifting frame 82 is movable vertically with respect to the frame member 74. Hydraulic means 84 are coupled between the frame member 74 and lifting frame 82 to accomplish relative vertical motion between the units. The lifting frame 82 has a generally flat upper surface 86 which has a U-shaped recess 87 sized to pass around the outer diameter of a riser section. A riser pipe section 24 has diametrically opposed pin members 88 perpendicularly arranged relative to the axis of a riser pipe and supported by plate members 89 welded to the upper sides of the pins 88 and to the sides of a riser pipe section. The surface 82 of the frame 82 has recesses 90 therein to receive the pins 88 so that a riser section is interlocked by the pins to the lifting frame.

As shown in FIG. 8, the arms 35 which provide the upper support for the riser pipe sections can include transverse locking bars 92 to retain the upper portion of the pipes in a steady condition. The crane 27 can move to the stored riser pipe sections and the fork lift device can be lowered below the crane 27 to engage the pins 88 of a riser pipe section. The arms 35 for storage are located relative to the pins 88 so that the lifting portion of fork lift device can be inserted between the arms 35 and pins 88. The riser pipe sections are stacked and removed one at a time from side to side of the racking arms 35.

In summary of the overall operation of the system, the crane 27 first picks up the lower end 33 of a BOP and moves it to the opening 19. The BOP portion 33 is lowered partially through the opening 19 with the

door sections

40 and 50 in a retracted condition. Then, the door section 50 which has beams for supporting the BOP 33, is moved to an extended position where the door section 50 supports the BOP portion 33 relative to the cellar floor. The bridge crane 27 is then used to move an upper BOP section 32 over the lower section 33 and the

BOP sections

32 and 33 are connected. After connection-of the upper BOP section 32 to the lower BOP section 33, a single joint of riser pipe that has been pre-position'ed on the hook of the traveling block 16 by means of a running tool (not shown) is lowered through the rotary table 18 and connected to the top of the asembled BOP stack. The BOP stack is then picked up sufficiently for clearance and the door sec tion 50 of the sliding door 20 is retracted to allow passage through the cellar deck opening 19 of the BOP. After the BOP has been sufficiently lowered to clear the cellar deck opening 19, a second pair of door arms 40 are engaged to the first set of arms 50 that previously supported the BOPS. The interconnection of the two sets of

arms

40 and 50 is accomplished by inserting pins in the holes 40c and 50g while the door is in the retracted position. The door 20 is then manipulated again to an extended position with the now engaged second set of arms 40 that are spaced apart sufficiently to provide clearance for the riser and to support a riser spider 37 which will support the riser and BOP connected to it. The riser spider 37 is then installed around the riser and supported by the second set of arms 40. The riser is then set in it. The running tool (not shown) is then released and pulled up sufficiently to provide clearance for the next joint of riser. The fork lift device 31 is moved to the riser pipe section storage area and another riser pipe section is picked up vertically and transported in a vertical condition to the cellar opening 19 where it is lowered and coupled to the riser joint setting in the riser spider. The running too] (not shown) attached to the traveling block 16 and is lowered through the rotary table 18 to attach to the connected riser pipe section. After connection with the running tool, the assembled stack is picked up sufficiently to release the spider and then is lowered until the riser pipe section is in position to be supported by the riser spider which is supported by the door section 40. The door section 40 then supports the depending stack by support of the riser pipe section by the

door sections

40 and 50 coupled to one another.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from the invention in its broader aspects; and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. In an offshore drilling system on location in a body of water, a method for manipulating riser pipe sections between a stored condition of individual sections in a storage area in a drilling rig and an operational condition of sections coupled to one another to define a riser string where said riser string extends downwardly from the drilling rig toward the floor under the water, said method comprising the steps of coupling the draw works of a drilling rig to the riser string and lifting the riser string through an opening in a riser storage floor until at least the upper end of said riser string is below the rotary table on the rig floor and at least one riser section is above the riser storage floor,

releasably supporting the riser string at said opening in said riser storage floor, releasably coupling a horizontally movable transfer means to the upper end of a riser section just below the rotary table, disconnecting the draw works from the riser string and disconnecting such riser pipe section from the riser string at a location above said opening, raising such uncoupled riser pipe section on the horizontal transfer means to clear the end of the supported riser string and transferring such uncoupled riser pipe section in a horizontal direction while in a vertical condition to a storage area on the same level, at such storage area, lowering such uncoupled riser pipe section with respect to the horizontal transfer means into a storage position on a pipe rack, and

securing such uncoupled riser pipe section to said pipe rack.

2. The method as defined in claim 1 snd further including the performance of the following steps while a riser pipe section is being moved to the storage area,

coupling the draw works of the drilling rig to the supported riser string immediately following the initiation of the transfer of an uncoupled riser pipe section to the storage area, releasing the support of said riser string at said opening and lifting the riser string through said opening to position at the next riser section in the riser string above the riser storage floor, and

releasably supporting the riser string at said opening in said riser storage floor.

3. In an offshore drilling system on location in a body of water, a method for manipulating riser pipe sections between a stored condition of individual sections in a storage area in a drilling rig and an operational condition of sections coupled to one another to define a riser string where said riser string extends downwardly from the drilling rig toward the floor under the water, said method comprising the steps of moving a riser pipe section from a storage area to a location below a draw works,

coupling the draw works to such riser pipe section and raising the riser pipe section into the drilling rig,

moving a blow out preventer from a storage area to a location below the draw works,

supporting the blow out preventer at the opening in a riser pipe storage floor, and lowering the raised riser pipe section to said blow out preventer,

coupling said riser pipe section to said blow out preventer,

coupling the blow out preventer to the riser pipe sec tion, releasing the support for the blow out preventer and lowering the riser pipe section and blow out preventer through the opening in the riser storage floor until at the upper end of said riser pipe section is just above the riser storage floor,

releasably supporting the riser pipe section at said opening in said riser storage floor,

releasably coupling a horizontally movable transfer means to the upper end of another riser section, disconnecting the draw works from the riser pipe section, and connecting such other riser pipe section to the riser section in the opening to define a riser string depending from said opening,

coupling the draw works to said riser string, releasing the support at said opening and lowering said riser string to a location where the upper end of the riser string is just above said opening, and

releasably securing such riser string in said opening.

4. The method as defined in claim 3 and further including the performance of the following steps while the riser pipe string is lowered through said opening, the steps of coupling a horizontally movable transfer means to a pipe section in a storage area on the riser storage floor and transferring such pipe section toward said opening while said pipe string is being lowered through said opening.

Claims

1. In an offshore drilling system on location in a body of water, a method for manipulating riser pipe sections between a stored condition of individual sections in a storage area in a drilling rig and an operational condition of sections coupled to one another to define a riser string where said riser string extends downwardly from the drilling rig toward the floor under the water, said method comprising the steps of coupling the draw works of a drilling rig to the riser string and lifting the riser string through an opening in a riser storage floor until at least the upper end of said riser string is below the rotary table on the rig floor and at least one riser section is above the riser storage floor, releasably supporting the riser string at said opening in said riser storage floor, releasably coupling a horizontally movable transfer means to the upper end of a riser section just below the rotary table, disconnecting the draw works from the riser string and disconnecting such riser pipe section from the riser string at a location above said opening, raising such uncoupled riser pipe section on the horizontal transfer means to clear the end of the supported riser string and transferring such uncoupled riser pipe section in a horizontal direction while in a vertical condition to a storage area on the same level, at such storage area, lowering such uncoupled riser pipe section with respect to the horizontal transfer means into a storage position on a pipe rack, and securing such uncoupled riser pipe section to said pipe rack.

2. The method as defined in claim 1 snd further including the performance of the following steps while a riser pipe section is being moved to the storage area, coupling the draw works of the drilling rig to the supported riser string immediately following the initiation of the transfer of an uncoupled riser pipe section to the storage area, releasing the support of said riser string at said opening and lifting the riser string through said opening to position at the next riser section in the riser string above the riser storage floor, and releasably supporting the riser string at said opening in said riser storage floor.

3. In an offshore drilling sysTem on location in a body of water, a method for manipulating riser pipe sections between a stored condition of individual sections in a storage area in a drilling rig and an operational condition of sections coupled to one another to define a riser string where said riser string extends downwardly from the drilling rig toward the floor under the water, said method comprising the steps of moving a riser pipe section from a storage area to a location below a draw works, coupling the draw works to such riser pipe section and raising the riser pipe section into the drilling rig, moving a blow out preventer from a storage area to a location below the draw works, supporting the blow out preventer at the opening in a riser pipe storage floor, and lowering the raised riser pipe section to said blow out preventer, coupling said riser pipe section to said blow out preventer, coupling the blow out preventer to the riser pipe section, releasing the support for the blow out preventer and lowering the riser pipe section and blow out preventer through the opening in the riser storage floor until at the upper end of said riser pipe section is just above the riser storage floor, releasably supporting the riser pipe section at said opening in said riser storage floor, releasably coupling a horizontally movable transfer means to the upper end of another riser section, disconnecting the draw works from the riser pipe section, and connecting such other riser pipe section to the riser section in the opening to define a riser string depending from said opening, coupling the draw works to said riser string, releasing the support at said opening and lowering said riser string to a location where the upper end of the riser string is just above said opening, and releasably securing such riser string in said opening.