CROSS REFERENCE TO RELATED APPLICATIONS
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This application claims priority based on U.S. Provisional Patent Application No. 61/150,709 filed Feb. 2, 2009.
1. FIELD OF THE INVENTION
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The invention disclosed and claimed herein relates to apparatus (commonly called a “pipe wiper”) for stripping excess drilling fluid (commonly called “drilling mud” or simply “mud”) from the exterior of pipe or tubing (commonly called “drill string”) used to drill and/or complete earth-bores (“hole” or “well”) as said pipe or tubing is being removed (“pulled”) from the earth-bore (“hole” or “well”).
2. GENERAL BACKGROUND
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During drilling or completion of an earth-bore (“hole” or “well”) some form of drilling fluid (“mud”) is typically used for a variety of reasons, to lubricate and cool the drill bit, to circulate drill cuttings to the surface, provide a fluid pressure to keep the well from blowing out and other reasons. In many cases the mud contains ingredients which are hazardous to personnel and constitute environmental pollutants, is viscous and tends to cling to pipe or tubing being pulled from the earth-bore.
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During the course of drilling an earth-bore it is common to for the pipe or tubing to require removal from and reinsertion into the hole for several reasons, including but not limited to changing worn bits. When pulling pipe or tubing from the hole, mud clinging to the exterior of the pipe or tubing presents a problem. If allowed to fall on the work-floor of the drill rig can present a slip hazard. If allowed to remain on the pipe or tubing as it is lifted and/or stored vertically in the derrick can, particularly in windy weather blow off the pipe and injure the eyes of skin or personnel or blow off of the drilling rig and pollute the environment. In addition thereto mud which is allowed to fall on the floor of the rig, where it must be washed from, not only consumes unnecessary time and labor but the mud become diluted, may no longer be usable, constitute a disposal problem and require new mud to be purchased. For these reasons and others it is desirable to remove at least a majority of the mud clinging to the exterior of drill pipe or tubing off as it is being pulled from the hole.
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Because of the need to remove at least a majority of mud from the exterior of drill pipe or tubing prior to the time the drill pipe or tubing comes up through the work-floor of the drilling rig a number of prior devices and/or techniques have been developed.
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One way previously developed to “strip” or “wipe” mud from exterior of pipe or tubing as it was being from an earth-bore (“hole” or “well”) containing drilling mud (“mud”) was to is to place a circular piece of rubber (or other elastic material) having a centrally disposed hole (commonly called a “donut”) around the exterior of pipe or tubing and below the work-floor of the drilling rig. As pipe or tubing was lifted the donut would rise with the pipe or tubing until the donut contacted the bottom of the rotary table or other part of the bottom of the work-floor of the drilling rig. At that point the donut was unable to rise further as pipe or tubing was pulled further upward and started stripping mud from the exterior of the pipe or tubing. As the donut is made of elastic material, the larger diameter (“upset”) tool joints were able to pass through the donut.
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There are, however, certain limitations to use of a donut pipe-wiper. One is installation of the donut. If the donut is cut radially installation is facilitated but then the donut cannot grip the pipe tightly. If on the other hand the donut is not cut, then installation on the pipe is difficult. In either case, drilling mud is usually abrasive and tends to rapidly enlarge the hole of the donut, making it less effective or require replacement. Because of these, and other problems, associated with donut-like pipe wipers it is not uncommon to see drilling rigs running with loose, ineffective donut wipers or running without any form of pipe wiper.
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Another type of pipe wiper disclosed in prior art is that of “surrounding framework” design, such as seen in U.S. Pat. No. 5,842,252. In general wipers of this design are characterized by surrounding framework which included two movable, blade-carrying assemblies, each of which blade-carrying assemblies was moved by a pair of hydraulic or pneumatic cylinders the base of which was attached to said surrounding framework.
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While pipe-wipers of the “surrounding framework” design were generally effective wiping pipe there were certain disadvantages attendant to their usage. Pipe wipers of said design are typically large, heavy, bulky, complex and expensive. They were typically too large to install from the work-floor of the drilling rig (through the opening in the work-floor created by removal of the master bushing from the rotary table of the work-floor). On the other hand they were difficult, if not impossible, to install from the side in the limited amount of space between the bottom of the work-floor and the pollution pan (“drip pan”) of the drilling rig. Due to this type of pipe wipers utilization of a surrounding framework they could not be installed with pipe suspended from the work-floor of the drilling rig. If this type of wiper became worn or damaged they were difficult to access, remove, repair and install a repaired or new unit. Because of these limitations it is not uncommon to see drilling rigs running with ineffective, inoperative pipe wipers of this type of design or being operated without any form of pipe wiper.
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The invention disclosed and claimed herein seeks to address the above mentioned limitations of previous pipe wipers. An object of the disclosed invention is to provide a pipe wiper which is small and light enough be installed from the work-floor of a drilling rig. Another object of the invention is to provide a pipe wiper of which may be installed with pipe or tubing hanging through the work-floor of the drilling rig. Another object of the disclosed invention is to reduce the complexity, weight, expense of frames, cylinders, hoses and the like, making the unit more facile and less expensive to install, use and maintain. A further object of the invention is to make it easy to place in and take out from under the rotary table, thus keeping it out of the way during drilling. Yet another object of the invention is to provide a simple split design that can be installed, removed and/or more easily maintained even if there is drill pipe in the hole.
3. SUMMARY OF THE INVENTION
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This invention discloses a mechanized pipe wiper that utilizes a pair of opposing wiper elements, one of which is slidably disposed in a pair channels formed in the other. The wiper elements are moved toward (“closed”) and apart from (“opened”) each other by only two air cylinders. When closed the wiper elements surround the exterior of the pipe or tubing When opened the wiper elements allowed for the pipe or tubing to be rotated or large items to be run through the pipe wiper. By removal two pins, one attaching each air cylinder, the pipe wiper can be split into two “halves” which can be easily installed around pipe in the hole.
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The disclosed invention utilizes the fixed actuator assembly to hold the base of the air cylinders and contains a channel in which the sliding actuator assembly is slidably disposed, eliminating the need for a surrounding frame. Also, because of the simple, robust design of the disclosed invention, a housing is also not needed. The disclosed invention can be installed and removed, either for installation or maintenance, from the work-floor of the drilling rig simply by putting it through the opening created by removal of the master bushing from the rotary table of the work-floor.
4. BRIEF DESCRIPTION OF THE DRAWINGS
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For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which, like parts are given like reference numerals, and wherein:
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FIG. 1 is a cross section of the drill pipe being pulled from the hole with the disclosed invention under the rotary table;
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FIG. 2 is a plan view of the drill pipe being pulled from the hole with the disclosed invention under the rotary table;
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FIG. 3 is a plan view of the disclosed invention in the open position;
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FIG. 4 is a cross section view of certain components of the disclosed invention in the open position;
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FIG. 5 is a plan view of certain components the disclosed invention in the closed position;
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FIG. 6 is a cross section view of certain components of the disclosed invention in the closed position;
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FIG. 7 is a cross section view of the disclosed invention being placed through the rotary table of a drilling rig;
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FIG. 8 is a plan view of the disclosed invention being placed through the rotary table of a drilling rig;
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FIG. 9 is a plan view of a wiper element of the disclosed invention;
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FIG. 10 is an elevation view of a wiper element of the disclosed invention;
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FIG. 11 is a plan view of certain components the fixed actuator assembly of the disclosed invention;
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FIG. 12 is an end elevation view of certain components of the fixed actuator assembly of the disclosed invention as would be seen from the pipe.
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FIG. 13 is a plan view of the sliding actuator assembly of the disclosed invention;
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FIG. 14 is a plan view of the clamp of the disclosed invention.
5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
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While the present invention will be described with reference to preferred embodiments, it will be understood by those who are skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. It is therefore intended that the present invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments and legal equivalents thereof.
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Looking at FIG. 1, drill pipe (20) is being wiped as it is pulled from the hole through the rotary table (22) and master bushings/slips (21) while the disclosed invention (23) disposed below rotary table (22) and is stripping and wiping the mud (25) from the exterior of drill pipe (20). The pipe wiper of the invention (23) may be held in place by any flexible means, such as chains, wire or other type of suitable rope which holds the pipe wiper (23) in a generally horizontal position below rotary table (22), allows sufficient lateral movement for the pipe wiper (23) to move laterally as the pipe or tubing may wobble, but limits rotational movement of pipe wiper (23) about the pipe (20) and prevents the pipe wiper (23) from falling to the well-head of the earth-bore.
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Looking now at FIG. 2, we are looking down on the drill pipe (20) and rotary table (22). Disclosed invention (23) is below rotary table (22), and master bushing (21).
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FIG. 3 is a plan view of the disclosed invention (23) in the open position with slide assemblies (15) removed (so that air cylinder components (30 & 39) may be more readily seen). The body of air cylinders (30) are attached to fixed actuator assembly (32) of the disclosed invention by straps, bolts, welding and other means known to those skilled in the art for attaching air cylinders to structural components. Sliding actuator assembly (38) is connected to the air cylinder rod (39) by means of a clevis (40) and pin (36). Air cylinders (30) moves sliding actuator assembly (38) of the disclosed invention between open and closed positions.
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Both the fixed actuator assembly (32) and the sliding actuator assembly (38) are equipped with a wiper element (33), which will made of semi-rigid material which is durable, non-sticking and soft enough not to damage the exterior of pipe. High density polyurethane and other thermoplastics of similar characteristics are preferred materials for wiper elements (33). Each wiper element (33) has a hemispherical opening (34) located at the center of the wiper element (33) for encircling one-half of the outer circumference of drill pipe (20). The wiper elements (33) have edges (35) which taper towards hemispherical opening (34) for guiding drill pipe (20) to hemispherical openings (34) of each wiper element (33) as the pipe-wiper of the disclosed invention is closing on drill pipe (20).
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Each wiper element (33) is secured to a respective base (47 or 57, seen in FIGS. 4 and 6) by clamp (46). Both clamp (46) and wiper elements (33) may have mating holes (50) through which to place bolts, screws, rivets or other fastening means (48) for attaching one clamp (46) to base (47) of fixed actuator assembly (32) and attaching another clamp (46) to base (57) of sliding actuator assembly (38).
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In FIG. 4, we see the side view of the disclosed invention (23) without the air cylinders (30) or slide assemblies (15) for better viewing of the actuator assemblies (32 and 38) of the invention herein disclosed.
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In FIG. 5. we see the disclosed invention (23) in the closed position with slide assemblies (15) removed (so that air cylinder components (30 & 39) may be more readily seen). Air cylinders (30), pull the wiper elements (33) of the fixed actuator assembly (32) and the sliding actuator assembly (38) against drill pipe (20). Hemispherical opening (34) encircle the circumference of drill pipe (20).
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FIG. 6 is a side view of the disclosed invention in the closed position without the air cylinders (30) or slide assemblies (15) for better viewing of the actuator assemblies (32 and 38) of said invention.
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FIG. 7 is a cross section view of the disclosed invention (23) being lowered through the rotary table (22). Master bushings (21) may be removed to make a larger opening for the for the disclosed invention (23) to be lowered through rotary table (22).
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FIG. 8 shows a plan view of the disclosed invention (23) being lowered through the rotary table (22).
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FIG. 9 is a plan view of the wiper element (33). Two wiper elements (33) are required, one for fixed actuator assembly (32) and another for sliding actuator assembly (38). Wiper elements (33) may have holes (50) to permit the placement of bolts, screws, rivets or other fastening means (48) therethrough.
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FIG. 10 is a elevation view of the side of wiper element (33).
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FIG. 11 is a plan view of the fixed actuator assembly (32). Wiper element (33) is mounted and held in place by a clamp (46) which is attached to fixed base (47) by bolts, screws, rivets or other fastening means (48). Holes (50) are provided in clamp (46) and in wiper element (33) The body of air cylinders (30), not shown in this view, are mounted to flanges (17) attached by bolts, screws, rivets or other fastening means to the sides of fixed base (47) extending laterally outside of fixed base (47). In the preferred embodiment of the invention flanges (17) will have a vertical portion (better seen in FIG. 12) to facilitate attachment to fixed base (47) and prevent contact between slidable assembly (38) and air cylinder (30).
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Also shown in FIG. 12 are slide assemblies (15). As is shown slide assemblies (15) have a portion which over-hangs a portion of fixed actuator assembly (32) forming a channel between clamp (46) of fixed actuator assembly (32) and the bottom of the over-hanging portion of the slide assemblies (15). In said channel sliding actuator assembly (38) is free to move longitudinally over fixed actuator assembly (32) but is constrained from moving vertically or laterally.
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FIG. 13 is a plan view of the sliding actuator assembly (38) where the clamp (46) is placed on top of the sliding actuator assembly (38) for clamping wiper element (33) to the sliding base (57). Bolts, screws, rivets or other fastening means (48) pull clamp (56) through wiper element (33) to the sliding base (57). Holes (58) are for putting pin (36) through clevis (40) of air cylinder rod (39).
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FIG. 14 is a plan view of clamp (46) with holes (50) used to clamp the wiper element (33) to the fixed base (47) of fixed actuator assembly (32) or the sliding base (57) of the sliding base assembly (38).
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In the embodiment of the pipe wiper (23) disclosed above sliding actuator assembly (38) is shown slidably disposed over fixed actuator assembly (32). More specifically the bottom of sliding base (57) is shown slidably abutting the top of fixed base (47). In this embodiment it is necessary to restrain sliding actuator assembly (38) from being lifted from fixed actuator assembly (32) when pipe wiper (23) is closed against pipe or tubing (20) and pipe or tubing (20) is being lifted (in order to pull pipe or tubing (20) from the earth-bore). slide assemblies (15) are provided on each side of fixed actuator assembly (32) for such purpose. In preferred embodiment of the invention slide assemblies constitute a length of “angle-iron” (or other similarly shaped piece of aluminum or other suitable metal) one angle of which is attached to the side of fixed actuator assembly (32) and the other angle of which projects horizontally towards the longitudinal axis of fixed actuator assembly (32), thereby forming a channel between the top of clamp (46) of fixed actuator assemble (32) and the bottom of slide assembly (15) in which sliding actuator assembly (38) can slide over fixed actuator assembly (32) without becoming disengaged.
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However sliding actuator assembly (38) may be easily disengaged from fixed actuator assembly (32) if desired. By removing pins (36) from clevises (40) sliding actuator assembly (38) may be slid out of the ends of the channel between the top of clamp (46) of fixed actuator assembly (32) and the bottom of slide assembly (15). This effectively splits the pipe wiper of the invention into two halves, each of which is open, may be fitted around pipe or tubing (20) and connected back together by using pins (36) to attach cylinder rods (39) back to clevises (40), thereby much facilitating installation or removal of the pipe wiper (23) of the present invention as compared to pipe wipers of previous design.
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Those skilled in the art will recognize that there is actually no right side or down with the invention (23) disclosed herein, the fixed actuator assembly (32) could be on the top of sliding actuator assembly (38) rather than the reverse as shown specifically disclosed herein, said disclosure intending to be illustrative of the principals of the invention rather than exhaustive of every embodiment of the inventive concept disclosed herein.
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Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in any limiting sense.
