Patent Application
20190112880
The present invention relates to a guided telescoping system for a snubbing or drilling assembly providing an integrated guiding and support structure.
Snubbing is the act of putting drillpipe or other rigid tubing into a wellbore when pressure is contained in the well. Snubbing is necessary when tubing, with or without one or more tools on it, needs to be run into a live well which is at high pressure.
There are two main forces that must be overcome in snubbing: the well pressure and the frictional resistance of the blow-out preventer (BOP) through which the drillpipe or tubing is being moved. These pressures can be extreme and will cause several stresses on the drillpipe or tubing as they are inserted into the well bore, including axial stress (compression or tensile), radial stress (burst and collapse), hoop (shear), and torque (rotational stress). For the safety of the site and workers, jackplate guides or tubing guides are used to help mitigate some of these extreme pressures experienced by the drillpipe or tubing. Current pipe guiding apparatuses in typical snubbing units make use of one or several telescoping tubes positioned between stationary and traveling snubbing slips.
In a typical snubbing operation, the drillstring or tubing string is made up by connecting multiple threaded drillpipe or tubing joints together and snubbing them into the wellbore.
A typical snubbing assembly comprises a gin pole mast that is raised and lowered to pick up joints of tubing or drillpipe and position them for making up the drillstring; a work basket at the top of the snubbing assembly, supported on several work basket support beams that extend down to the rig floor; a rotary jackplate, travelling slips and rotary jackplate motor, a hydraulic assembly including hydraulic cylinders, guide tubes, a set of stationary slips near the rig floor, and a blowout preventer (BOP).
A tong unit is typically also used with the snubbing unit, and is located in the work basket, either loose or mounted on a hinged arm that this clamped to a side of the work basket. In order to make up or break out a joint of tubing, the tong is manually moved and positioned around the tubing joint by an operator, then actuated to grip and torque the joint into or out of threading with a next joint. The moving, positioning and operation of the tong is a common problem area in snubbing operations, leading to either injury of operators or poor positioning leading to damage to the tubing joint during a makeup or break out attempt.
The rotary jackplate and travelling slips are typically supported and moved by the hydraulic cylinders. In this sense, in addition to extending and retracting to lift and lower the jackplate and travelling slips, the hydraulic cylinders must also provide anti-rotation resistance and support to the assembly. Hydraulic cylinders are limited to certain load limits that determine how much a cylinder can be extended or retracted in operation, depending on the loads needed to be supported and moved by the cylinders. As a result of these additional rotational, torqueing and compressive forces on the hydraulic cylinders, hydraulic cylinders in snubbing units commonly reach their load limits far short of a full stroke length. Therefore multiple strokes are required to full snub a length of pipe into the well.
In some embodiments, to relieve some stress on the hydraulic cylinders, additional jackplate supports extending down to the rig floor are added to the assembly to prevent rotation of the jackplates and the snubbing assembly as the drillpipe is threaded and snubbed into the wellbore. The jackplate guide tubes reduce potential cylinder damage while rotational force is applied to the cylinder rods, but require additional space and assembly time.
Snubbing assemblies are traditionally assembled in a number of stages and parts, due to the number of components involved. Firstly the rotary jackplate and motor are connected to one another and then lifted and bolted onto the hydraulic cylinders and/or jackplate guiding tubes. The jackplate structure is next lifted and bolted onto the workbasket, which has been previously affixed to its working basket support beams and to the gin pole mast. The tubing guide and hydraulic cylinders are affixed to the work basket as well.
Erecting snubbing assemblies is therefore time consuming and complex. Transportation by truck requires at least two semi-trailers to carry all of the equipment to site and the number of steps needed for assembly requires multiple operators, adding cost and time to snubbing operations. Multiple components and multiple assembly personal also increase risks to workplace safety.
A number of attempts have been made to improve snubbing processes. US Patent Application 20120006565 teaches pipe guide apparatus for guiding a pipe during snubbing and includes a stationary pipe guide and a travelling pipe guide each define a pipe opening and has a flexibly resilient guide member having an opening with a diameter closely matching the outside diameter of the pipe being snubbed.
US Patent Application 20080053661 teaches a method of guiding tubing for hydraulic jacks that includes multiple guide plates attached to the hydraulic jack rods and a lateral support section to prevent buckling. U.S. Pat. No. 8,333,238 teaches a snubbing unit where the support frame comprises a work platform. The support frame consists of top, bottom and side plates with an opening for the tubing and is connected directly to the blow out preventer. U.S. Pat. No. 7,117,948 teaches a snubbing unit for running and retrieving a string of tubing into a well under pressure selectively operates in a standalone mode and a rig assist mode. The unit has a lower frame for mounting during the stand alone mode on a snubber blowout preventer. Stationary weight supporting slips and snubbing slips are carried by the lower frame during the stand alone mode.
U.S. Pat. No. 5,115,861 describes a method to support tubing during snubbing where there are upper and lower horizontal beams which vertical support legs between the beams. US Patent Application 20130126186 teaches a method for a wellbore tubular handling system having support plates attached to the snubbing device.
However, there still remains a need for guided jackplate assemblies for snubbing units that are more fully supported and allow for longer snubbing stroke length. There is also a need to simplify assembly of snubbing systems to save time, labour and costs, and to make assembly safer.
A pipe guiding system is provided for use with a snubbing assembly. The system comprises a work basket supported on one or more work basket supports; a travelling jackplate having travelling slips and supported on the one or more work basket supports; one or more hydraulic cylinders and a tubing guide. The work basket supports, travelling jackplate, travelling slips, one or more hydraulic cylinders and tubing guide form a singular, integral jackplate guiding unit.
A method is further provided for assembling a pipe guiding system. The method comprises the steps of assembling a singular, jackplate guiding unit to a work basket; and assembling the work basket and the singular integral jackplate guiding unit to a gin pole mast, The jackplate guiding unit comprises one or more work basket supports, a travelling jackplate, one or more hydraulic cylinders and a tubing guide.
It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
A further, detailed, description of the invention, briefly described above, will follow by reference to the following drawings of specific embodiments of the invention. The drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings:
The drawing is not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features.
The description that follows and the embodiments described therein are provided by way of illustration of an example, or examples, of particular embodiments of the principles of various aspects of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention in its various aspects.
With reference to the Figures, the present invention comprises a guided telescoping drilling system 2 for snubbing rigs. The system 2 is used with a telescopic ginpole mast 4 with means (not shown) for picking up a drill pipe or tubing joint and raising it into an opening 6 within a work basket 8. The work basket 8 is supported by telescoping work basket supports 10.
In a unique and novel design of one embodiment of the present invention illustrated in
The present invention further uniquely comprises an all-in-one jackplate guiding unit 14 consisting of the work basket 8, work basket support 10, jackplate supports 10, a jackplate 12 and associated travelling slips 18, hydraulic cylinders 20 and an extendable tubing guide 16 which are integrally built as a single jackplate guiding unit 14. The jackplate guiding unit 14 is serves a number of purposes including preventing the jackplate 12 from torqueing or buckling under the extreme forces during snubbing processes.
By combining supporting the jackplate 12, motor and traveling slips 18 on the work basket supports 10 and by creating an all-in-one jackplate guiding unit 14, assembling the full snubbing assembly 2 is made simpler, safer and quicker.
The work basket supports/jackplate supports 10 are telescopic to allow travel up and down of the work basket 8 relative to the jack plate 12, as seen in the differing position of the work basket 8 relative the jackplate 12 between
The combination is a faster and more compact to rig-up. Furthermore, the compact design reduces the number of trucks needed to bring the equipment to the wellbore site, less personnel are required for assembly, and with fewer assembly steps, risks are reduced and the rigging process becomes safer.
The hydraulic cylinders 20 serve to raise and lower, the jackplate 12, with the travelling slips 18, as the drill pipe is fed into or raised out of the wellbore. The drill pipe is snubbed inside the extendable tubing guide 16, which prevents buckling or bending of the joint of tubing or drillpipe as it is moved axially downwardly in snubbing.
As previously noted, the rotary jackplate 12, with travelling slips 18 and motor (not shown) provide rotational movement and torque forces during drill string snubbing. The jackplate guiding unit 14 and particularly the unitary work basket supports/jackplate supports 10 reduce torqueing strain on the hydraulic cylinders. The work basket supports/jackplate supports 10 also support axial loads of the jackplate 12 as it carries tubing sections and snubs them into the wellbore or pulls them out of a wellbore.
The support provided by the work basket supports 10 not only provides for stability to the jackplate 12 but it also allows for more sustained snubbing action, without needing to relieve rotational forces for fear of the assembly twisting. Since axial and rotational loads in the present invention are supported by the work basket supports 10, the hydraulic cylinders 20 are under reduced load and stress, and in particular, lessens torque stresses. This in turn allows the hydraulic cylinders 20 to extend and retract further before reaching their load limits. The longer stroke achievable by the hydraulic cylinders 20, while the jackplate applies rotational torque to the tubing string, means that a longer section of tubing can be snubbed in one stroke before stopping, griping the tubing in the stationary slips, raising the jackplate 12, reseting the travelling slips 18 and snubbing again, thus making snubbing operations faster. The same would be true, in reverse, for pulling tubing out of the ground.
Furthermore, by modifying known snubbing elements and arrangements into a unified guiding system 14 rather than separate tubing guide module and jackplate guide module, there is less chance of error in assembly.
While the above description focuses primarily on snubbing a drillstring into a wellbore by gripping and then making up and lowering a joint of tubing or drill pipe down into the wellbore, it would be well understood by a person of skill in the art that the present systems and methods are equally applicable to pulling a drillstring or tubing string out of a wellbore. In such cases, the jackplate 12 with motor and travelling slips 18 is telescopically lowered on the unified jackplate guiding unit 14 to grip an upper end of a drill pipe or joint of tubing and raised to raise the string out of the ground, where it is broken out from the drill string or tubing string by rotation, picked up by the gin pole mast 4 and lowered to the rig floor.
In both snubbing a drillstring into the ground and pulling a drillstring out of the ground, the snubbing assembly 2 must always control the forces acting on the drillstring. When the drillstring is not long and the weight of the drill string is less than the wellbore pressure, axial downwards force is required to force the drill string into the wellbore during snubbing and also to ensure that the drill pipe or joint of tubing does not spring up and out of the wellbore when being broken out. In such cases, the work basket supports 10 serve to support the jackplate guiding unit 14 and allow the hydraulic cylinder to retract and snub into the well with the necessary axial force and torque. When the drillstring is long enough and the weight of the drill string is greater than the wellbore pressure then sufficient assembly strength and gripping is required to hold the drill string at the mouth of the wellbore and not allow the string to fall down the well.
In a preferred embodiment, the present work basket 8 is also laterally extendable to enlarge the working surface of the work basket and provide more floor space for operators. In this embodiment, the work basket 8 can be laterally reduced to meet load and sizing requirements for shipment via truck as part of the unified jackplate guiding unit 14, and can then be laterally extended once mounted at the wellbore. More preferably, the work basket 8 is extended by hydraulic means.
In a further preferred embodiment, the present work basket is built with a lower riser for housing and holding the jackplate when the hydraulic cylinders are extended. This lower riser ensure that the jackplate, travelling slips and auxiliary equipment are positioned at such a height that an operator can easily reach to makeup or breakout the tubing sections, without the need to work at a height above the operator's head.
In a second embodiment of the present invention, illustrated in
In the second embodiment, the work basket 8A is provided with an integrated, fixed tong unit 24 that is more preferably located just below a floor of the work basket 8A and is fixed in position to the fixed riser 10A. By providing an integrated tong 24 that is already fixed into positon for making up and breaking out operations, the operation of making up and breaking out becomes more automated. There are less moving parts in the work basket 8A, leading to less chance for operator injury. Furthermore, by fixing the position of the tong 24, the drillpipe or tubing joint need only be lowered into place by the ginpole 4A, leading to more precise positioning of the joints for makeup and breakout. In the present invention, the tong unit 24 may move somewhat vertically within the riser 10A, said movement being controlled by the hydraulic cylinders 20.
The integrated tong 24 can be any standard tong well known in the art for makeup and breakout purposes and can particularly include any standard tongs known for use on snubbing rigs. Alternatively, the tong may be specially design to fit and operate on the riser 10A. Since the integrated tong 24 controls and manages all of the torqueing load for makeup and breakout operations, there is no need to especially design the fixed riser 10A to carry or handle any additional loads. However, customizations to the fixed riser 10A for optimal operation within the present arrangement would be understood by a person of skill in the art as being encompassed by the scope of the present invention.
In this embodiment of the present invention, the work basket 8A is fixed to the fixed riser 10A and does not raise or lower. More preferably, the height of the fixed riser 10A is selected such that the work basket 8A, with the integrated tong 24 positioned just below it, are at a fixed height that is higher than the full extension of the jackplate 12A. This ensures that the workbasket 8A and tong 24 extending thereblow are always clear of the travelling jackplate 12A as it is raised and lowered for snubbing operations. Most preferably, the fixed riser 10A is supported on a lower work floor 28, said lower work floor 28 corresponding to a lowest-most height of the jackplate 12A when it is lowered. The lower work floor 28, may optionally further provide a platform from which operators can inspect and maneuver parts of the snubbing unit at the level of the lower work floor 28. The hydraulic cylinders 20A support the jackplate 12A to the rig floor.
The fixed riser 10A of the present invention, while serving as the fixed support for the work basket 8A, still also serves as a support for the jackplate 12A. With reference to
The fixed riser 10A further preferably provides, on an outer surface thereof, means for moving equipment, controls, instrumentation and/or one or more operators vertically along the snubbing unit 2. There is often a desire to inspect the drillpipe or parts of the snubbing unit below the workbasket 8A, or a need to get measurements or images from these areas. In the present invention, in a preferred embodiment, Alternatively, the elevator unit 32 may take the form of a smaller sized work basket in which an operator may stand, together with controls or instrumentation. In a further preferred embodiment, the smaller work basket format of the elevator unit 32 may comprise a control console from which the operator may take measurements, take images, and control operations of the snubbing unit and parts thereof, in addition to making a visual inspection. Operation of the elevator unit 32 in its small work basket form may be controlled by the operator within the small work basket, optionally via the control console or by other elevator operating means, to raise and lower the elevator unit 32 along the rails 26.
As an alternatively arrangement to a fixed riser 10A to keep the jackplate 12A from hitting the integral tong 24, it is also possible to mount the integral tong 24 on a raisable and lowerable platform (not shown) that is vertically moveably connected to the work basket 8A such that the raisable and lowerable platform can be raised up in to the work basket 8A to avoid contact with jackplate 12A and lowerable to a tong operating position
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2017/000100 | 4/26/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62327592 | Apr 2016 | US |
