JPS6364594B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved jack mechanism that can be placed in a well drilling rig and used to lower a casing string into a well drilled by the rig. This jack is particularly desirable for use in deep wells where the casing string is too heavy to be suspended and supported by moving blocks and other conventional equipment on the rig. This jack is placed at the location in the rig where the rotary table was located during drilling, and is located in the center of the well in order to operate the two gripping units in a relatively vertical direction to successively lower the casing. It includes a piston-cylinder mechanism located on either side of the axis.

The present invention provides an improvement over the general type of jack mentioned above, and particularly in several respects, it reduces the load forces exerted by the lowered weight to the ground at the location where the rig is located, using a minimum structure. and preferably without exerting said forces on the rig frame structure itself;
It relates to a method of lowering and transmitting. These results are accomplished in large part by utilizing the cylinder of the piston-cylinder mechanism driving the jack as a load-bearing member for transmitting the force due to the load to an underground supported base. These piston-cylinder mechanisms have lower portions extending perpendicularly on either side of the central axis of the well, preferably on both diametrical sides with respect to this axis, and supported on the base. The first pipe gripping structure is supported by the upper part of the piston-cylinder mechanism in such a relationship that the force loads exerted therefrom are transmitted downwardly through the cylinder, and thus The gripping structure is supported directly from the base via these cylinders. A piston cooperating with the cylinder has a rod projecting upwardly beyond the cylinder, and a second pipe gripping unit is supported by the piston and has two rods for releasably gripping, supporting and lowering the casing. There are 2 gripping units
each supported by two upper structures. In assembling the jack, the two cylinders are inserted through openings in the positioning template, which acts to hold the cylinders in a predetermined spaced relationship.

These and other features and objects of the invention will become apparent from the following description of representative embodiments of the invention, which are illustrated in the accompanying drawings.

In FIG. 2, a frame well drilling rig is shown generally at 10. The well drilling rig 10 is
a mast or excavation tower 11 that projects upward;
The horizontal floor 12 of the rig is spaced upward from the ground 13 at the lower end of the tower 11, and the horizontal floor 12 and the mast 1
1 and a lower structure 14 supporting the same. Drill·
A tensioning device 15 is used to raise and lower a moving block 17 suspending strings and other equipment into the well.
acts via cable 16. FIG. 2 shows the rig after actually drilling a well underground, and at this time the jack 19 in which the present invention was implemented
0 string is placed in the rig to lower into the well.

FIG. 1 shows the rig during drilling operations, where a conventional rotary table 21 is placed in a central recess or central opening 22 in the floor 12 of the rig, with the rotary table extending across the underside of the recess 22. It is supported by a pair of parallel beams 23 extending from one side to the other. beam 23
may be identical shaped beams as shown,
These are located on either side of the vertical axis of the rig and well and are connected to the rig substructure 14 at both ends. The rotary table 21 operates via a conventional master bushing, schematically indicated as 25, and a square bushing, which drives a non-circular kelly 26 and its connecting drilling pipe 27 in rotation about an axis 24. , well drilling will be carried out.

The jack 19 may have sufficient load handling capacity, including the rig frame structure consisting of the mast 11 and the support structure 14, the tensioning device, the operating line 16, the crown block 28, and the moving block 1.
7 and other related equipment exceeds the load handling capacity. For example, the tensioning equipment, rig frame structure, and associated equipment for suspending the drill string 27 are capable of supporting and driving drill strings weighing up to 500 tons. Such load handling capacity appears to be sufficient to support the drill string to the desired depth, but does not support the greater weight of the string of casing 20 required to line a hole of the same depth. I cannot support it.
Therefore, the jack 19 has a considerably greater load handling capacity than, for example, a tensioning device, e.g. the ability to support loads of up to 1000 tons, thus making it possible to use rigs with heavier load carrying capacity during drilling operations. However, even the rig described above can lower very heavy casings into the ground.

Referring to FIG. 3, the jack 19 consists of a jack containing two representative identical piston-cylinder mechanisms 29, which are supported at their lower ends on a base 30, which is supported from the ground plane. be done.

A concrete foundation 31 is placed in a hole or recess 32 (Figure 2) drilled in the ground to help accommodate the heavy loads of the casing string.
Two horizontal metal plates 33 are placed on the upper surface of this foundation at ground level, and these metal plates 33
The base 30 can be engaged with and supported by the base 30. The casing 20 extends downwardly between the piston-cylinder mechanisms 29 and further through a blowout preventer 34 mounted at the top of the well.

The base 30 preferably takes the form of a rigid structure assembled from a number of metal parts, suitably bolted or otherwise secured, on either side of the casing and well axis. form two similar upwardly projecting portions 35 and 36. Upper projecting portions 35 and 36 are part 3
7 and 38 (Fig. 7),
Portions 37 and 38 are located just above the ground, and also below the lateral projecting portion 40 of the lowest blowout preventer.
It is located below the . base 30
The tops of the upwardly projecting portions 35 and 36 may take the form of a horizontal metal plate 39 on which the pistons are mounted.
A cylinder mechanism 29 is installed.

The two piston-cylinder mechanisms 29 may be identical and extend vertically along two vertical parallel axes 40 and 41, which axes 40 and 41 are the main axes of the rig and well. 24 and equally spaced diametrically on both sides of this principal axis. Each piston-cylinder mechanism 2
The cylinder 42 of 9 has a tubular side wall 43 which is cylindrical on the inside and outside about the axis 40 or 41 and whose lower end is closed by a horizontal bottom wall 44 . The horizontal bottom wall 44 engages with the side wall 42 and is fixed thereto by welding or the like, and is placed on the upper side of the corresponding upper plate 39 of the base 30. The lower end of the cylinder 42 is restrained from horizontal movement from a predetermined position on the base structure by a plurality of positioning lugs or positioning fingers 45, which are welded to the plate 39 and project upwardly therefrom. At this time, the positioning finger 45 engages with the outer surface of the lower end portion at a circumferentially spaced position. That is, finger 45
A socket structure is formed by the cylinder 4.
The lower end of 2 is insertable into the socket structure in a positioning relationship. As shown in Figure 7, 4
Two lugs 45 may be equally spaced around each cylinder 42. The upper ends of these lugs 45 may be provided with cam surfaces 46 which slope downwardly as they proceed radially inwardly toward axis 40 or 41, thereby causing the cylinder to move downwardly within the socket structure. When the cylinder is guided to the center position.

Piston 47 of each piston-cylinder mechanism 29
is slidably engaged with the cylinder 42 and is aligned with the axis 4
It can reciprocate up and down along 0 or 41. Piston 47 is piston rod 48
and a piston rod 48 projects upwardly through an upper end 49 of cylinder 42 in sealing relation. Pressurized working fluid is selectively supplied to the upper or lower end of the cylinder via a working fluid supply 51 to the conduit schematically shown as 50 under the control of an operator on the floor 12 of the rig; This is accomplished by actuating control elements in panel 52, typically through a suitable pilot valve assembly. By forcing pressurized working fluid out of the lower end of the cylinder and injecting pressurized working fluid into its upper end, the piston moves downwardly relative to the cylinder, whereas by reversing the working fluid line connections, the piston moves downwardly relative to the cylinder. Move upward.
During the downward movement of the piston, it is preferable to adjust the flow rate of the working fluid discharged from the lower side of the piston by changing the opening degrees of two adjustable choke valves 53. In this case, the casing 20 is also controlled by the jack 20. It is possible to accurately and reliably control the descending speed when descending.

The upper ends of both cylinders 42 are positioned in a desired mutually spaced relationship by downwardly passing through a cylinder positioning and locking frame or template 54. The template 54 can be made from essentially flat metal plate members which are secured by suitable welding or the like as shown in FIGS. 3 and 6. This template or frame 54 consists of two similar parallel spaced apart rigid metal strips 55 which are rigidly connected by transverse connecting members 56, thereby
Two spaced apart, typically rectangular openings 57 are formed. The openings 57 are sized to snugly accommodate the cylinder 42 while maintaining the axes 40 and 41 in the proper spacing. Frame or template 5
4 is also formed with a rectangular central opening 58 between the two rectangular openings 57, which is dimensioned to extend downwardly through the extension of the casing 20.
Prior to inserting the piston-cylinder mechanism 29 downward into the central opening 22 in the floor 12 of the rig, the frame 54 is placed on the upper side of the two horizontal flanges of the rotary table support beam 23 so that the piston-cylinder mechanism is inserted into the opening. 57 downwardly.

The cylinder 42 carries a number of connecting brackets or lugs 59 equally spaced around its outer surface above the level of the stereotaxic template 54 , with a number of typically U-shaped links 61 connecting the horizontal pins 60 . It is pivotally connected to the eye lug 59. Screw 161 extends vertically through the opening in link 61 and template 54 . The screw 161 can be provided with a head bearing downwardly against the link and a nut bearing upwardly against the template, thereby holding the cylinder against the template and preventing upward movement of the cylinder. be done. However, cylinder 42
can move slightly downward relative to the template due to the vertical spacing shown between link 61 and template 54. This is because during such downward movement of the cylinder, the screw can move downwardly through the insertion opening of the template and relative to the template.

Template 54 is held in a fixed position by attaching it to beam 23, such as with a number of L-shaped clamps or fasteners 123. The clamp 123 extends through the opening in the template 54 and its lower end is bent under the flange of the beam 23, against which the clamp 123 is tightened by a threaded connection with a nut at its upper end.

Each cylinder 42 carries an annular flange 62 directly above the connecting lug 59 . The flange 62 can be formed as a rigid ring of metal or the like welded to its outside. Above the flange 62, the cylinder 42 supports a first upper transverse support structure 63, which
A first casing gripping unit 64 is carried on top. The upper end of piston rod 48 similarly carries a second upper support structure 65 for vertically actuating the same. A second gripping unit 66 is carried on the support structure 65 . The support structure 65 may typically have an external shape as shown in the plan view of FIG. Also,
As shown in FIG. 4, support structure 65 includes upper and lower rigid metal horizontal plates 67 secured by vertically extending members 68 that extend through unit 65 and along axis 24. It is shaped to form a relatively large central vertical aperture 69 centered thereon, and on either side of the aperture 69 two smaller apertures 70 centered on the cylinder axes 40 and 4.
will be provided. The aperture 70 is dimensioned to accurately accommodate and snugly fit the reduced diameter end of the piston rod 48 with the annular shoulder of the piston rod 48 on the upper side. It faces toward the bottom and engages the lower plate 67 of the unit 65, so that it is supported from the piston rod. A retaining ring 73, housed in a groove in the upper end of the piston rod, engages the upper plate 67 around the opening 70, thereby locking the unit 65 to the piston rod for upward and downward movement together. It's becoming like that. The gripping unit 66 has a lower horizontal side surface 74 which engages the upper horizontal side surface of the upper plate 67 of the support structure 65, with the unit 66 being secured to the upper plate 67 and extending along the circumference. It is centered with respect to the axis 24 by being accommodated between a number of evenly spaced positioning lugs 75 (typically four lugs).
The lug 75 is preferably provided with a camming surface 76 which slopes downwardly as it progresses radially inwardly, thereby centering the unit 66 on the support structure 65.

The support structure 63 to which the cylinder is mounted is constructed essentially the same as the structure 65 described above, and includes a relatively large central opening 77 and two smaller openings 78 located on diametrically opposite sides. but the opening 78 is sufficiently larger than the corresponding opening 70 in the upper structure 65 so that the cylinder 4
2 is accommodated in the correct position.
The gripping unit 64 is attached to the upper horizontal plate 79 of the structure 63.
and is positioned by a lug 175 which corresponds to the lug 75 already mentioned for structure 65.

The two gripping units 64 and 66 are identical and of the known type with wedge-shaped slides for releasably gripping and supporting the casing. The upper part of the gripping unit 66 is the eighth
Illustrated schematically in the figure, it includes an outer annular rigid body 80 provided with a downwardly tapered inner sliding surface 81 engageable with a wedge-shaped sliding member 82, thereby As the slide member 82 moves downwardly relative to the annular rigid body 80, the cam action guides the slide member inwardly into gripping engagement with the casing. The inner surface 83 of the slide member 82 is formed with gripping dies or teeth 84 which are adapted to bite into the surface of the casing and provide effective support thereto. The sliding member 82 is suspended by a ring 85, and the sliding member is connected to the ring 85 by a link 86, so that when the sliding member is moved up and down, the link 86 moves radially inwardly and outwardly. Can move. Such up-and-down movement is accomplished by a number of circumferentially spaced piston-cylinder mechanisms 87, the cylinders being connected to the rigid body 80 and the pistons being connected to the ring 85. Needless to say, when the sliding member is in the operating position shown in solid lines in FIG.
In the retracted position, shown in dashed lines in the figure, the casing is free to move downwards relative to the sliding member.

To briefly summarize and explain the operating cycle of the illustrated apparatus, it is assumed that the rig is initially in the state of FIG. That is, in that state, the rotary table 21 is placed in the recess 22 of the floor 12 of the rig, and at this time the rotary table 21 is placed in the kelly 26.
and the drill string connected thereto, at the same time the drill string is suspended by the moving block 17 and gradually lowered under the control of the tensioning device 15. The rig frame structure, tensioning equipment, moving blocks, lines 16, etc. typically have a maximum load handling capacity of 500 tons, and the total weight of the drill string at maximum hole depth is well within this limit. . If the weight of the casing to be lowered into the borehole exceeds this limit, the rotary table 21 is removed from the rig and the rig 19 is placed in the rig as shown in FIG. This jack typically has a load handling capacity of up to 1000 tons and is therefore sufficient to support very heavy casings. Figures 9-11 schematically illustrate several steps in installing the jack into the rig.
The first step is to position the cylinder positioning frame or template 54 into the rig by lowering the template 54 into the recess 22 in the floor of the rig and positioning the beam 23 as shown in FIG. the support position on the upper side and then with the element 123 the template 5
4 to the beam 23. After positioning and locking the template 54 in this way, the two piston-cylinder mechanisms 2
9 is lowered from a position above the floor of the rig along the respective axes 40 and 41 to a supporting position on the base 30, the lower end of the cylinder being inserted into the socket structure formed by the lug 45. be accommodated. The insertion position of such a piston-cylinder mechanism is illustrated in FIG.

The next step is to attach the first upper support structure 63 to the first
The piston-cylinder mechanism is moved downward from the broken line position shown in FIG. The lower side of the lower plate 88 engages the horizontal upper side of the flange 62 around the front opening 78, whereby the support structure 63 is effectively supported via the cylinder 42. The gripping unit 64 can then be positioned on the structure 63 and the second upper support structure 65 can be moved downwardly from the dashed line position in FIG. 11 to the solid line position in the figure, where the piston The upper end of the rod is received within the opening 70 of the structure 65, and the structure 65 is effectively supported and vertically movable by the piston rod and is supported by the piston rod by a ring 73. - Held on rod 48. The upper gripping unit 66 can then be placed on the structure 65 to put the jack into operation.

Each length or each section of the casing 20 is
As shown, it can be lowered along axis 24 by a moving block to a position where it connects to another string of casings suspended in the well. During the lowering of a length of casing pipe in this manner, the casing string already placed in the well is gripped by the gripping unit 64, and the casing section to be added is removed as shown in FIG. It is lowered by the upper gripping unit 66 as shown in FIG. During or after connecting the casing compartment to the string, the piston
The cylinder mechanism 29 is actuated to raise its piston, the upper support unit 65, and the gripping unit 66 mounted thereon to the position indicated by the dashed line in FIG. 2, at which time the sliding member of the gripping unit is released. The unit 66 is then able to effectively grip and support the casing string by actuating the sliding member. The lower gripping unit 64 is then released by upward actuation of its sliding member, so that the casing string is free to move downward under the control of the jack 19. Such downward movement is accomplished by actuating a valve control in panel 52 to expel pressurized fluid from the lower end of cylinder 42 and to allow pressurized fluid to flow into the upper end of each cylinder, in this case the lower end. The discharge of pressurized fluid from the piston is regulated by the choke valve 53 to lower the piston and its associated components at a controlled variable flow rate that satisfies the prevailing operating conditions.
After the upper gripping unit 66 and its support structure 65 have been lowered to the solid line position shown in FIG. 2, the sliding members of the lowering gripping unit 64 are actuated to grip the casing string again. At the same time, the sliding member of the upper unit 66 is released, and this release causes the unit to return upward to the position shown by the dashed line, and the lowering operation is repeated.
In this way, the casing is attached to the gripping unit 66
The casing string is lowered step by step by repeating the ascending and descending movements of the structure 65 and the structure 65, in which case the casing string is suspended by the unit 64 during the ascending motion of the unit 66, and During its downward movement it is suspended by the unit 66.

When the weight of the casing string is suspended by the gripping unit 64 during jacking, the entire load of the string is transferred from the unit 64 and its support structure 63 to the side wall 43 of the cylinder 42 of the piston-cylinder mechanism 29. It is transmitted downward through the support base 30, the concrete foundation below it, and the ground. When the upper gripping unit 66 is supporting a string, the force of the load is similarly transmitted downwardly via the piston-cylinder mechanism.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway view of a drilling rig during well drilling. FIG. 2 shows the rig of FIG. 1 with the rotary table removed and the jack of the present invention placed inside. FIG. 3 is a partially exploded enlarged view of the jack in FIG. 2. FIG. 4 is a partial side view taken along line 4--4 of FIG. FIG. 5 is a plan view taken along line 5--5 of FIG. Figures 6 and 7 are line 6- in Figure 3.
FIG. 6 is a horizontal cross-sectional view taken along lines 6 and 7-7. Figure 8 shows one of the slip-type gripping units, line 8 in Figure 5.
A longitudinal cross-sectional view along -8 is abbreviated. Figure 9, 1st
Figures 0 and 11 are diagrams showing the steps in assembling the jack on the rig. 10... Rig, 11... Mast, 19... Jacket, 20... Casing, 24... Center axis line,
27... Casing string, 29... Piston-cylinder mechanism, 30... Base structure, 42
...Cylinder, 43...Cylinder wall, 47...
Piston, 63...Other units, 65...Casing support unit.

Claims (1)

[Claims] 1. A jack used in a well drilling rig having an upwardly protruding mast, wherein the jack, after drilling a well with the rig, leaves the mast in its drilling position and lowers the load-bearing capacity of the mast. is operable to lower a heavy casing string into the well, said jack comprising a cylinder and a piston on each side of the central axis of the well and two casing support units, one of the casing support units being operable to lower a heavy casing string into the well; is supported by said piston and is operable by said piston to move upwardly and downwardly, without transmitting the forces due to the load of the casing through said mast used for excavation; A jack, characterized in that the casing unit is supported by the upper part of the cylinder from the base structure at the lower end of the cylinder through the cylinder wall.