1. Field of the Invention
The present invention relates to a system for performing earth borehole operations and, more particularly, to a hybrid system for conducting both jointed pipe and coiled tubing (CT) operations.
2. Description of Prior Art
The use of coiled tubing (CT) technology in oil and gas drilling and servicing has become more and more common in the last few years. In CT technology, a continuous pipe wound on a spool is straightened and injected into a well using a CT injector. CT technology can be used for both drilling and servicing, e.g., workovers.
The advantages offered by the use of CT technology, including economy of time and cost are well known. As compared with jointed-pipe technology wherein typically 30-45 foot straight sections of pipe are threadedly connected one section at a time while drilling the wellbore, CT technology allows the continuous deployment of pipe while drilling the well, significantly reducing the frequency with which such drilling must be suspended to allow additional sections of pipe to be connected. This results in less connection time, and as a result, an efficiency of both cost and time.
However, the adoption of CT technology in drilling has been less widespread than originally anticipated as a result of certain problems inherent in using CT in a drilling application. For example, because CT tends to be less robust than jointed-pipe for surface-level drilling, it is often necessary to drill a surface hole using jointed-pipe, cement casing into the surface hole, and then switch over to CT drilling. Additionally, when difficult formations such as gravel are encountered down-hole, it may be necessary to switch from CT drilling to jointed-pipe drilling until drilling through the formation is complete, and then switch back to CT drilling to continue drilling the well. Similarly, when it is necessary to perform drill stem testing to assess conditions downhole, it may again be necessary to switch from CT drilling to jointed-pipe drilling and then back again. Finally, a switch back to jointed pipe operations is necessary to run casing into the drilled well. In short, in CT drilling operations it is generally necessary for customers and crew to switch back and forth between a CT drilling rig and a jointed-pipe conventional drilling rig, a process which results in significant down-time as one rig is moved out of the way, and the other rig put in place.
Another disadvantage of CT drilling is the time consuming process of assembling a (bottom-hole-assembly (BHA)—the components at the end of the CT for drilling, testing, well servicing, etc.), and connecting the BHA to the end of the CT. Presently, this step is performed manually through the use of rotary tables and make-up/breakout equipment. In some instances, top drives are used but the CT injector and the top drive must be moved out of each others way, i.e., they cannot both be in line with the borehole. Not only does this process result in costly downtime, but it can also present safety hazards to the workers as they are required to manipulate heavy components manually.
To address the problems above associated with the use of CT technology and provide for selective and rapid switching from the use of a CT injector to a top drive operation, certain so-called “universal” or “hybrid” rigs have been developed. Typical examples of the universal rigs, i.e., a rig which utilizes a single mast to perform both top drive and CT operations, the top drive and the CT injector being generally at all times operatively connected to the mast, are shown in United States Patent Publication 2004/0206551; and U.S. Pat. Nos. 6,003,598, and 6,609,565. Thus, in U.S. Publication 2004/0206551 there is disclosed a rig adapted to perform earth borehole operations using both CT and/or jointed-pipes, the CT injector and a top drive being mounted on the same mast, the CT injector being selectively moveable between a first position wherein the CT injector is in line with the mast of the rig and hence the earth borehole and a second position wherein the CT injector is out of line with the mast and hence the earth borehole.
In all of the systems disclosed in the aforementioned patents and publications, the reel of CT and the CT injector are on or are carried by the same carrier. Heretofore in CT operations particularly drilling, well depth has been limited to about 2200 meters because of governmental regulations regarding the weight and/or height of loads moving on highways. A CT injector can weigh from 2,500 to 39,000 lbs or more depending upon its size. As to the CT itself, 2200 meters of 3½″ CT, including the reel upon which it is wound can weigh up to 100,000 lbs. Thus, because of governmental regulations regarding weight that can be transported on highways, reels of 3½″ CT exceeding about 2200 meters cannot be transported on most highways since the combined weight of the CT and the CT injector would exceed the weight limitations. Clearly it is possible to transport greater lengths of smaller diameter, e.g., 2⅞″ CT. However, particularly in using CT to conduct drilling operations at depths of about 2200 meters, the hydraulics of fluid flow, e.g., flow of drilling mud, dictate that the CT be 3½″ or greater in diameter.
In copending U.S. patent application Ser. No. 11/300,842 filed Dec. 15, 2005 for a System, Method and Apparatus for Conducting Earth Borehole Operations, incorporated herein by reference for all purposes, one solution to overcoming height and weight problems vis-à-vis traveling on regulated roads/highways and the like is disclosed.
In one aspect, the present invention provides a system for use in conducting earth borehole operations, the system comprising a first support or carrier; a mast mounted on the first support; a second support or carrier; a skid carried on the second support; a CT injector carried on the skid, the skid being movable from the second carrier to the first carrier such that the CT injector is supported or carried on the first carrier, the CT carrier being movable from a first, transport position or mode, to a second, operational position or mode wherein the CT injector can insert or withdraw CT into and out of a wellbore; and a reel of CT for supplying CT to the CT injector.
In the following description, the terms “carrier,” “support,” “substructure” may be used interchangeably as referring to any structure, be it fixed or movable, in the form of a trailer, skid, framework, etc., and which can carry or support a load, e.g., a CT injector, a mast with or without a top drive, a reel of CT or for that matter any other piece of equipment commonly used in hybrid rigs of the type under consideration. The word “skid” as used herein refers to any platform, framework or other type structure which can support a load as described above and which is capable of being moved from a first position or location to a second position or location by sliding movement, rolling movement, etc.
Referring then to
Shown adjacent substructure 10 is a mast, indicated generally as 20, mast 20 being carried on a wheeled carrier comprising a front semi-trailer 22 and a rear booster trailer 24, both of trailers 22 and 24 being of the wheeled variety as shown and pulled by a tractor (not shown). Thus, mast 20 can be moved over highways and other terrain to a desired drilling site. Mast 20 is connected via a winch line 26 to the winch (not shown) of a winch truck (not shown) or some other hydraulic or mechanical system whereby mast 20 can be moved onto substructure 10 as described hereafter.
Turning now to
With reference to
Referring now to
Attached to skid 48 is a frame, shown generally as 60, frame 60 comprising mirror image spaced frame members, only one of which is shown, frame 60 having a generally vertical strut 62, an angled brace 64 and a cross member 66, cross member 66 being connected to strut 62 by an elbow 68. CT injector 50 is connected to frame members 60 by means of first and second booms 70, booms 70 like frame members 60 being spaced apart (see
A hydraulic cylinder 100 has one end pivotally attached as at 102 to CT injector 50. Hydraulic cylinder 100 is held in the position shown in
Turning now to
Turning now to
As can be further seen from
In the embodiment shown in
Referring now to
Referring now to
As can be seen, there is a movable stand shown generally as 400 having a top 402 which forms a cradle or a support surface, the stand having four vertical legs only two of which, 404 and 406, are shown. As best seen with reference to
In the position shown in
Referring now to
As can be seen from the above description, the hybrid system of the present invention provides numerous advantages over prior art systems. For one, since the coil of CT, the CT injector and the mast can all be on separate, wheeled carriers if desired, the system can be more easily moved along regulated highways without exceeding weight restrictions. Thus, the system of the present invention is ideal for conducting CT drilling operations in wells as deep as 3,000 to 4,000 meters.
In the description above, reference has been made to CT injector 50 resting on skid 48. It is to be understood, as noted above, that skid 48 can comprise any structure which is movable, e.g., from trailer 40 to first support 10, and which has a surface, framework or the like to support CT injector 50. In point of fact, support 10 is usually of the skid form having a framework as shown and which provides working platforms for rig personnel as well as a support or carrier for mast 20 and skid 48. Thus, support 10 can be winched onto a trailer for transport to a desired site. Accordingly, skid is in no manner intended to be limited to a sliding structure but rather to a movable structure which has the capability of supporting a load, e.g., CT injector 50.
In the description above, the word “surface” has been used in referring to various structural elements of the hybrid system of the present invention. The word “surface” as used herein is intended to include not only a planar or substantially planar surfaces but any system or structure which can be comprised of beams or other support members which can cooperatively act to provide a support, be it a platform or the like, upon which a load, e.g., skid 48, can rest.
In the description above, the terms “operatively attached” or “operatively connected to” or similar terms employing the word “operatively” may have been employed. Those terms are intended to mean, for example, that if Component A is being described as operatively attached to Component B, Component A may be directly attached to Component B or can be attached to Component B via Component C, the net result being that Component A and Component B are interconnected in such a way that both Component A and Component B can perform in their intended manner. For example, if it is stated that the CT injector is operatively attached to the frame on the skid, the connotation is that the CT injector is interconnected to the frame, directly or by some intermediate component which permits the CT injector to, in this case, be moved between various positions with the frame as a supporting member.
It will be understood that while not shown, the various trailers, carriers, etc., would have, to the extent necessary, power sources such as motors, generators, hydraulic systems and the like, as is conventionally used in conducting earth borehole operations of the type under consideration, i.e., drilling, completion and/or workover of oil and gas wells or for that matter any type of earth borehole, e.g., water well, wells or boreholes used in mining, etc.
The foregoing description and examples illustrate selected embodiments of the present invention. In light thereof, variations and modifications will be suggested to one skilled in the art, all of which are in the spirit and purview of this invention.
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Number | Date | Country | |
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20070209791 A1 | Sep 2007 | US |