Clamp-On Drill String Wiper

Abstract

A clamp-on wiper that facilitates the cleaning of external surfaces of sections of a drill string or drill pipe to remove earth, drilling mud, and other solid/liquid compounds while the drill string is being handled on a drilling platform. The pipe wiper includes a split cylinder with two halves hinged together, each with a handle. Internal to each half cylinder are a number of half circle flexible squeegees that conform to the outside diameter of the drill string when the device is closed. The device may be handled by an individual and positioned around the pipe without the need for access to the end of the drill string. The user may close and hold the pipe wiper around the pipe while the drill string is moving upward so as to wipe liquid and solid debris from the pipe as it is raised.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to tools and equipment used in oil field drilling and pipe handling operations. The present invention relates more specifically to a device that facilitates the cleaning of the external surfaces of sections of drill string or drilling pipe to remove mud, drilling mud, petroleum products, and solid/fluid mixtures of such compounds, while the drill string or pipe is being handled on a drilling rig platform.

2. Description of the Related Art

A great deal of science and technology has been devoted to exploration and drilling for fossil fuels in recent years. The high cost of petroleum exploration and drilling operations has increased the need for efficiency in the operation of drilling rigs and the like. One aspect of the drilling process that is critical to efficient exploration, drilling, and production, is the safe and timely process of operating a drilling rig and platform. The safe and efficient operation of a drilling rig or drill platform depends greatly on the personnel and equipment that are utilized.

In a typical drilling process environment, the drill string or more specifically sections of drill pipe, are constantly being placed into or being pulled from the bore hole comprising the oil or natural gas well. Although this process can be dangerous at times, its safety and efficiency depends on the care taken by the workers in the handling of equipment, and to some extent, the ability of the workers to operate within a relatively clean and clear environment.

Efforts have been made in the past to provide drilling rig components that are fixed on the rig through which the drill string passes for the purpose of cleaning or clearing the external surface of the drill string of earth, drilling mud, and other solid/liquid products from the drill string as it is removed from the bore hole. For the most part, these existing systems are fixed on the rig (i.e., are not portable or capable of being handled directly by the workers) and require that an end of the drill string (typically the bit end of the string) pass longitudinally through the cleaning system in order for the system to operate. Such fixed systems tend to be complex and require hydraulic or pneumatic manipulation at remote valves to provide for the tightening of a cleaning ring-like structure positioned completely around the drill string. The operation of such fixed systems is inefficient at best and is commonly bypassed as drill string pipe operations on the drilling platform occur quite fast and often do not allow for the rapid activation or deactivation of any of these fixed debris wiping systems.

It would be desirable therefore to have a small, handheld and hand manipulated drill string cleaner that may be placed and positioned on the drill string without the need for access to the bit end of the drill string. It would be desirable if such a device could be easily manipulated by one or two platform workers and applied to the drill string on an as needed basis that could be rapidly positioned on the drill string or rapidly removed from the drill string. It would be desirable if such a device were lightweight to the extent that it could be readily grasped and lifted with one hand to a position on the drill string, and then held in that position by two hands of a single individual.

SUMMARY OF THE INVENTION

In fulfillment of the above and further objectives, the present invention provides a clamp-on wiper device that facilitates the cleaning of the external surfaces of sections of a drill string or drill pipe to remove earth, drilling mud, petroleum products, and other solid/liquid mixtures of such compounds while the drill string or drill pipe is being handled on a drill platform. The pipe wiper includes a split cylinder with two halves hinged together and fitted with handles on each half. Internal to each half cylinder are a number of half circle flexible squeegee components that generally conform to the outside diameter of the drill string or drill pipe when the pipe wiper device is closed around the drill string. The device may be handled by a single individual who may position it around the pipe without the need for access to the end of the drill string. The drill platform worker may close and hold the pipe wiper around the pipe while the drill string is moving (typically in an upward directed) so as to wipe or clean liquid and solid debris from the pipe as it is raised.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the wiper device of the present invention shown in a partially open configuration, apart from the drill string or drill pipe.

FIG. 2 is a front angle perspective view of the wiper device of the present invention shown in a closed configuration, still apart from the drill string or drill pipe.

FIG. 3 is a rear elevational view of the wiper device of the present invention shown in a closed configuration.

FIG. 4 is a top plan view of the wiper device of the present invention shown in a closed configuration.

FIG. 5 is a top plan view of the wiper device of the present invention shown in an open configuration.

FIG. 6 is a rear elevational view of the wiper device of the present invention shown in an open configuration.

FIG. 7 is a front elevational view of the wiper device of the present invention shown in an open configuration.

FIG. 8 is a perspective view of the wiper device of the present invention shown positioned for use, closed around a section of drill string on a drilling platform.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is made first to FIG. 1 for a perspective view of the wiper device of the present invention shown in a partially open configuration apart from the drill string or drill pipe. The perspective view shown in FIG. 1 provides the orientation of the device that would be required for the placement and positioning of the wiper onto a drill string or drill pipe. Pipe wiper 10 is generally constructed of two half cylindrical shells, first half shell 12 and second half shell 14. These half cylindrical shells are connected to each other through hinge array 16. In a preferred embodiment of the invention, the two half shells 12 & 14 are constructed from a cylindrical section of large PVC pipe that is split longitudinally with the two resulting half cylinders attached one to the other with hinge array 16.

Positioned on the outside face of each of first half shell 12 and second half shell 14 are first side handle 18a and second side handle 18b (18b not shown in the view of FIG. 1). It is by way of these side handles 18a & 18b that pipe wiper 10 is handled and manipulated to position it on the drill string and to close about the drill string where it may be held in position for use.

Internal to pipe wiper 10 is an array of semi-circular squeegees, the edges of which engage the outer wall of the drill string pipe and clear the drill string pipe of earth, drilling mud, and petroleum fluids. Two such squeegees are positioned on each of the two half shells 12 & 14 with first upper squeegee 20 and first lower squeegee 24 positioned on the internal wall of first half shell 12. In a similar manner, second upper squeegee 22 and second lower squeegee 26 are positioned on the interior wall of second half shell 14.

In the preferred embodiment, each of these semi-circular squeegees 20, 22, 24 & 26 are positioned and secured in grooves cut into the walls of the first and second half shells 12 & 14. As will be seen with greater clarity below, the arrangement of the squeegees provides an interlaced structure set longitudinally within the cylindrical structure of pipe wiper 10 and longitudinally along the drill string pipe, with first upper squeegee 20 offset from second upper squeegee 22. In turn, first lower squeegee 24 is offset below second upper squeegee 22 but above second lower squeegee 26. In this manner there are actually four squeegees that operate to clean mud and debris from the pipe at four separate longitudinal levels. This staggered arrangement also provides an outlet path within the otherwise closed cylindrical pipe wiper for the fluids and mud that are cleaned from the drill string to escape. In other words, any two opposing squeegees do not directly meet between the two half shells so as to seal off a compartment into which the fluids, mud, and debris could be retained. There is always an outlet below the stacked alternating array of squeegees for the mud, fluid and debris to fall as it is being cleaned from the drill string.

In addition to the staggered longitudinal positions of the squeegees, each individual squeegee is configured with an angular overlap that prevents there being a seam region that is not cleaned from the drill string. Squeegee overlap angle θ, which is a departure from a straight radius directed from the wall of pipe wiper 10 to a central cylindrical axis, insures that there is some overlap between the edges of the squeegees that make contact with the drill string. When pipe wiper 10 is closed around the drill string, this angular overlap ensures that all surfaces of the drill string are cleaned (wiped).

In use, an operator on the drilling platform will be able to pick up pipe wiper 10 by one or both of the side handles 18a & 18b, open it into the configuration shown in FIG. 1, and reach around the drill string pipe to surround the drill string from the side, and thereafter close pipe wiper 10 so that the squeegees make contact with the outside surface of the drill string. The user may then hold pipe wiper 10 closed using side handles 18a & 18b with sufficient pressure to force the liquids, drilling mud, and other debris from the pipe as the drill string is being lifted from the hole by the drilling rig. It is not necessary that significant force be exerted by the user in order to keep the pipe wiper closed in this manner, as there is typically very little hardened debris on the drill string pipe, and the rubber squeegee components of the device operate efficiently with very little direct force. The user may, however, provide just enough leverage holding onto the side handles 18a & 18b to properly maintain pipe wiper 10 closed such that each of the squeegees is in contact with the outer surface of the drill pipe. In fact, as described in more detail below, the device is designed with squeegees that are flexible enough that as blocks or collar junctions in the drill string pass through it (see FIG. 8), there is little or no force directing the pipe wiper open.

FIG. 2 is a front angle perspective view of the wiper device of the present invention shown in a closed configuration, still apart from the drill string or drill pipe. FIG. 2 is a perspective view of pipe wiper 10 once it has been closed, such as around a section of drill pipe. Pipe wiper 10 is again shown to comprise first half shell 12 and second half shell 14, in this view closed together to form the cylindrical enclosure that holds the various squeegees. In this view, first upper squeegee 20 and second upper squeegee 22 are shown as visible from the top of pipe wiper 10. The angular overlap between these two offset squeegee layers is also seen in this view. It is further noted, however, that as material is wiped from the pipe by any individual squeegee, it is possible for such material to flow out the bottom of the device because, as mentioned above, no two squeegees completely cut off such flow, stacked as they are in alternating levels.

In FIG. 2, first side handle 18a and second side handle 18b are shown positioned as they would be held by the user once pipe wiper 10 has been closed around a section of drill string. Given the dimensions of the preferred embodiment (a ten inch section of PVC that has been split into two parts), it is apparent how the user might easily hold the device and maintain it closed by handling the first side handle 18a and second side handle 18b and drawing the two half shells 12 & 14 together.

FIG. 3 is a rear elevational view of the wiper device of the present invention shown in a closed configuration. In FIG. 3, a preferred embodiment of the hinge assembly is shown. In this rear view of pipe wiper 10, the two half shells 12 & 14 are reversed in orientation as the back side (the hinged side) of the device is shown. Likewise, the position of first side handle 18a and second side handle 18b are reversed from the previous figures. The preferred embodiment of the hinge array shown in FIG. 3 is made up of hinge components positioned on each of the two half shells 12 & 14. First half hinge array 16a is positioned on first half shell 12, while second hang hinge array 16b is positioned on second half shell 14.

In the preferred embodiment these resilient but non-metal hinge components are molded or glued into the PVC shell components in the manner shown. Each of the two sides of an individual hinge component is positioned on opposing half shells 12 & 14. In the embodiment shown in FIG. 3, there are four hinge components that make up the overall hinge array 16. The only metal component in the hinge array is preferably a hinge pin that is press-fit between the hard rubber or polyurethane hinge component elements. The arrangement of these hinge pins and hinge components is such that after manufacture, the two components remain aligned and incapable of separation without breaking the hinge.

FIG. 4 is a top plan view of the wiper device of the present invention shown in a closed configuration. In the view of FIG. 4, pipe wiper 10 is again shown to comprise first half shell 12 and second half shell 14. First half hinge array 16a and second half hinge array 16b are shown positioned on one side (the back side) of pipe wiper 10. A slight gap is shown on the opposing side (the front side), although in actual use this gap would be closed as the user draws the device around the drill string and holds it tightly closed. Contact with the drill string by the staggered level squeegees may keep the pipe wiper 10 from closing completely, depending on the outside diameter of the drill pipe. The geometry of the squeegees, with first upper squeegee 20 and second upper squeegee 22 visible in the view of FIG. 4, is such as to create a somewhat smaller internal diameter for the pipe wiper device than the outside diameter of the drill pipe. This incrementally smaller diameter will ensure some level of pressure by the squeegees against the drill pipe so as to direct fluids, mud and debris off of the pipe. Because of the angular overlap, some incomplete closure of the pipe wiper around the drill string pipe is readily accommodated.

FIG. 5 is a top plan view of the wiper device of the present invention shown in an open configuration. FIG. 5 provides the same view as FIG. 4 except that pipe wiper 10 has been opened to its full extent. Although in actual use it would seldom be necessary to fully open pipe wiper 10 in this manner, the limits of hinge array 16 are such that first half shell 12 and second half shell 14 may be opened to the extent that the internal squeegees are fully exposed. This may be beneficial for purposes of cleaning the device. Once again in this view, first upper squeegee 20 and second upper squeegee 22 are visible with the additional squeegee layers positioned immediately below these top layers. The arrangement shown in FIG. 5 may be a configuration suitable for placement of the device on the drill platform, off to the side, open and ready for use, whereby the user may simply pick up the device by either first side handle 18a or second side handle 18b.

It should be noted here that there is vertical symmetry with the device in addition to diametrical symmetry, such that there is no top or bottom to the device when in use. In other words, the user may pick up the device by either handle, bring it around the drill string without needing to pay attention to the orientation of the device or which handle is being picked up first. Any way the device is picked up in its open condition, such as that shown in FIG. 5, by either handle allows the user to place it around the drill string pipe with ease.

FIG. 6 is a rear elevational view of the wiper device of the present invention shown in an open configuration. FIG. 6 provides a further view of the fully open pipe wiper 10 disclosing, in this case, the outer surfaces of first half shell 12 and second half shell 14. In this view, first side handle 18a and second side handle 18b are shown to be centrally positioned on each half shell 12 & 14 respectively, from top to bottom and left to right. This handle placement again permits the easy use of the device by not requiring any specific orientation. First half hinge array 16a is shown on first half shell 12, and second half hinge array 16b is shown on second half shell 14.

FIG. 7 is a front elevational view of the wiper device of the present invention shown in an open configuration. FIG. 7 provides an opposing view to that shown in FIG. 6, disclosing the internal faces of first half shell 12 and second half shell 14 with pipe wiper 10 fully open, as in FIGS. 5 & 6. In this view, hinge array 16 is shown connecting the two half shells 12 & 14 together, albeit on the outside surfaces of the half shells. On the inside surfaces of the two half shells 12 & 14, the staggered levels of the four squeegee components is seen more clearly. First upper squeegee 20 is positioned on first half shell 12, in an uppermost position. Longitudinally below that position, but on second half shell 14, is second upper squeegee 22. Back on first half shell 12, first lower squeegee 24 is positioned incrementally below second upper squeegee 22. Finally, second lower squeegee 26 is positioned incrementally below first lower squeegee 24, albeit on second half shell 14. In this view of FIG. 7, it is clear how debris wiped by upper squeegee 20 may find its way out the bottom of the device without being sealed off in its flow.

Also shown in this view of FIG. 7 are first handle attachment bolt 28a and second handle attachment bolt 28b. Whereas most of the components in the pipe wiper device are capable of either being press-fit into grooves (as in the case of the squeegees) or secured by hot welding or chemical adhesives (as in the case of hinge array 16), it may be preferable to secure the side handles 18a & 18b with more rigid attachment bolts in order to strengthen the point of force exerted on the device while in use. In this case, bolts positioned through holes drilled in the walls of first half shell 12 and second half shell 14, that are secured by threads internal to first and second side handles 18a & 18b, provide just such a strong point for handling.

Reference is finally made to FIG. 8 for a perspective view of the wiper device of the present invention positioned for use, closed around a section of drill string on a drilling platform. FIG. 8 discloses the manner in which the device of the present invention is preferably used. On a typical drilling platform, a drill string extends upward to the crane and elevator components of the drilling rig where it is lifted and lowered, and of course turned, to carry out its drilling function. As pipe is put into the hole, and as pipe is lifted out of the hole, various sections of drill string are added or removed. When pipe is being removed from the hole, it is typically covered by drilling mud, mud received from the drilling process, and other petroleum fluids that are always present in such oil and gas wells. In the process of lifting the drill string up, the device of the present invention finds its best use. As shown in FIG. 8, drill string 30 is being drawn up out of the hole and drilling mud 34 and other debris are present on the outside surface. In practice, the slips shown in FIG. 8 would be removed from the rotary table, while the drill string is lifted up by the rig. It is preferable to remove the material from the outside surface of the drill string as it is drawn up and as drill string sections are removed and placed to the side in a pipe rack.

Placement of pipe wiper 10 around drill string 30 as shown closes first half shell 12 with second half shell 14. This is typically accomplished by the user handling pipe wiper 10 by first side handle 18a and second side handle 18b and drawing the pipe wiper closed in the manner described above. This may be accomplished by pulling on the two side handles as from the user positioned in the view of FIG. 8, or if necessary, pushing on the two handles. It is also possible for two individuals to collectively handle the device, as there is no need to exert significant pressure on the device for it to achieve its function.

As indicated above, the size and geometry of the device and the squeegees positioned internal to the device are such that sufficient force is exerted on drill string 30 as to wipe a majority of the drilling mud 34 from the pipe. The squeegees are flexible enough within the device, even under the force associated with closing the device around the pipe, to allow drill collar 32 and the like to pass through the device with little more force than the passage of the drill string itself. The device of the present invention is therefore fully capable of operating across the diameter of standard drill pipe as well as the diameter of any collars or blocks that connect the drill string components together.

A variety of pipe wiper sizes are anticipated even though some variation in the outer diameter of the drill pipe may be readily accommodated by a given size pipe wiper device. It is also possible to fit a given size split cylinder with different size squeegees. The split PVC cylinder or “can” may, for example, match a ten inch diameter can with a five inch diameter pipe. A four inch pipe would match with an eight inch can and a two and three-eighths to three and one-half inch pipe could match with a six inch can. An even smaller can, on the order of three to four inches, could be used with oil pump sucker rods or the like.

Although the present invention has been described in terms of the foregoing preferred embodiments, this description has been provided by way of explanation only, and is not intended to be construed as a limitation of the invention. Those skilled in the art will recognize modifications of the present invention that might accommodate specific drilling platforms and oil and gas well drilling environments and structures. Those skilled in the art will further recognize additional methods for modifying the construction of the device and the materials used in its manufacture to accommodate variations in pipe sizes. Such modifications, as to structure, orientation, geometry, and even composition and manufacture techniques, where such modifications are coincidental to the type of drilling platform being utilized, do not necessarily depart from the spirit and scope of the invention.

Claims

1. A pipe wiper device for cleaning drilling mud and other fluids and debris from the outer wall of a drill string made up of sections of drill pipe, the pipe wiper device comprising:

(a) a first half cylinder shell section having an inside wall surface, an outside wall surface, and a cylindrical height;

(b) a second half cylinder shell section having an inside wall surface, an outside wall surface, and a cylindrical height, the second half cylinder shell section hingedly connected to the first half cylinder shell section along parallel edges thereof extending along the cylindrical height of each half cylinder shell section;

(c) at least one, generally semi-circular, curved squeegee positioned on the inside wall surface of the first half cylinder shell section; and

(d) at least one, generally semi-circular, curved squeegee positioned on the inside wall surface of the second half cylinder shell section.

2. The device of claim 1 further comprising a first handle positioned on the outside wall surface of the first half cylinder shell section and a second handle positioned on the outside wall surface of the second half cylinder shell section.

3. The device of claim 1 wherein the at least one curved squeegee positioned on the inside wall surface of the first half cylinder shell section comprises two parallel curved squeegees, and the at least one curved squeegee positioned on the inside wall surface of the second half cylinder shell section comprises two parallel curved squeegees; and

wherein the positions of each of the two curved squeegees on the first half cylinder shell section are offset along the cylindrical height from each other and from the positions of the two curved squeegees on the second half cylinder shell section.

4. The device of claim 1 wherein the position of the at least one curved squeegee on the first half cylinder shell section is offset along the cylindrical height from the position of the at least one curved squeegee on the second half cylinder shell section.

5. The device of claim 4 wherein the at least one curved squeegee on the first half cylinder shell section, and the at least one curved squeegee on the second half cylinder shell section, each comprise a wiper blade of resilient material having a curved outer attachment edge, a curved inner wiper edge, and two generally straight end edges, the outer attachment edge secured to the inside wall surface of the respective half cylinder shell section, and the curved inner wiper edge having a radius of curvature generally the same as the cylindrical radius of the drill pipe being cleaned.

6. The device of claim 5 wherein the two generally straight end edges of each of the curved squeegees each extend incrementally beyond the parallel edges of the respective half cylinder shell sections, whereby when the device is closed around a drill pipe, each of the at least one curved squeegees on the first half cylindrical shell section overlaps each of the at least one curved squeegees on the second half cylindrical shell section.

7. The device of claim 5 wherein the curved outer attachment edge of each of the curved squeegees is thick relative to the inner wiper edge and comprises a generally flat surface for securement to the inside wall surface of the respective half cylinder shell section, and wherein the curved inner wiper edge of each of the curved squeegees is thin relative to the outer attachment edge and comprises a generally pointed edge for contact with the drill pipe being cleaned.

8. The device of claim 1 wherein the first and second half cylinder shell sections comprise half cylinder sections of PVC pipe material.

9. The device of claim 1 wherein the inside wall surfaces of the first and second half cylinder shell sections each further comprise a plurality of recessed channels and the at least one curved squeegee on the first half cylinder shell section, and the at least one curved squeegee on the second half cylinder shell section, are each secured within one of the plurality of recessed channels.

10. The device of claim 1 wherein the first and second half cylinder shell sections are hingedly connected together by a plurality of pin-in-cylinder hinge element pairs, with a first half of each hinge element pair secured to the first half cylinder shell section and a second half of each hinge element pair secured to the second half cylinder shell section, a pin rotationally connecting the two halves of hinge element pair.

11. The device of claim 2 wherein the handles each comprise a post secured to the outside wall surface of the respective shell section, the post extending radially outward from the outside wall surface, each handle positioned in an orientation opposing the other handle.

12. A pipe wiper device for cleaning drilling mud and other fluids and debris from the outer wall of a drill string made up of sections of drill pipe, the pipe wiper device comprising:

(a) a first half cylinder shell section having an inside wall surface, an outside wall surface, and a cylindrical height;

(b) a second half cylinder shell section having an inside wall surface, an outside wall surface, and a cylindrical height, the second half cylinder shell section hingedly connected to the first half cylinder shell section along parallel edges thereof extending along the cylindrical height of each half cylinder shell section;

(c) two generally semi-circular, curved squeegees positioned in spaced parallel arrangement on the inside wall surface of the first half cylinder shell section;

(d) two generally semi-circular, curved squeegee positioned in spaced parallel arrangement on the inside wall surface of the second half cylinder shell section, wherein the positions of the two curved squeegees on the first half cylinder shell section are offset along the cylindrical height of the device from the positions of the two curved squeegees on the second half cylinder shell section; and

(e) a first handle positioned on the outside wall surface of the first half cylinder shell section and a second handle positioned on the outside wall surface of the second half cylinder shell section.

13. The device of claim 12 wherein the two curved squeegees on the first half cylinder shell section, and the two curved squeegees on the second half cylinder shell section, each comprise a wiper blade of resilient material having a curved outer attachment edge, a curved inner wiper edge, and two generally straight end edges, the outer attachment edge secured to the inside wall surface of the respective half cylinder shell section, and the curved inner wiper edge having a radius of curvature generally the same as the cylindrical radius of the drill pipe being cleaned.

14. The device of claim 13 wherein the two generally straight end edges of each of the curved squeegees each extend incrementally beyond the parallel edges of the respective half cylinder shell sections, whereby when the device is closed around a drill pipe, each of the curved squeegees on the first half cylindrical shell section overlaps each of the curved squeegees on the second half cylindrical shell section.

15. The device of claim 13 wherein the curved outer attachment edge of each of the curved squeegees is thick relative to the inner wiper edge and comprises a generally flat surface for securement to the inside wall surface of the respective half cylinder shell section, and wherein the curved inner wiper edge of each of the curved squeegees is thin relative to the outer attachment edge and comprises a generally pointed edge for contact with the drill pipe being cleaned.

16. The device of claim 12 wherein the first and second half cylinder shell sections comprise half cylinder sections of PVC pipe material.

17. The device of claim 12 wherein the inside wall surfaces of the first and second half cylinder shell sections each further comprise two recessed channels and the two curved squeegees on the first half cylinder shell section, and the two curved squeegees on the second half cylinder shell section, are each secured within one of the recessed channels on the respective shell sections.

18. The device of claim 12 wherein the first and second half cylinder shell sections are hingedly connected together by a plurality of pin-in-cylinder hinge element pairs, with a first half of each hinge element pair secured to the first half cylinder shell section and a second half of each hinge element pair secured to the second half cylinder shell section, a pin rotationally connecting the two halves of hinge element pair.

19. The device of claim 12 wherein the handles each comprise a post secured to the outside wall surface of the respective shell section, the post extending radially outward from the outside wall surface, each handle positioned in an orientation opposing the other handle.

20. A device for cleaning the outer wall of a drill string, the device comprising:

(a) a first shell section having an inside wall surface and an outside wall surface;

(b) a second shell section having an inside wall surface and an outside wall surface, the second shell section hinged to the first shell section;

(c) at least one squeegee fixed on the inside wall surface of the first shell section; and

(d) at least one squeegee fixed on the inside wall surface of the second shell section;

wherein the first and second shell sections are positioned around the outer wall of the drill string and are closed together to force the squeegees against the drill string, and wherein the device is moved along the drill string to wipe debris from the outer wall.