Abstract:
A drill pipe mountable wellbore cleaning tool apparatus is of an improved configuration that enables attachment to a drill pipe joint having first and second connector end portions and a cylindrically shaped portion in between the connector end portions. The drill pipe joint with attached debris cleaning tool or tools is made part of a drill string. The apparatus includes a support sleeve that is mounted to the drill pipe joint in between the connector end portions. The support sleeve abuts but does not invade the integrity of the cylindrical portion. Centralizers are attached to the opposing ends of the support sleeve, with each centralizer overlapping a portion of the support sleeve. The support sleeve carries one or more debris cleaning tools in between the centralizers. These tools enable debris to be removed from a wellbore. At least one locking clamp is attached to the cylindrical portion next to a said centralizer. The locking clamp prevents the support sleeve from moving longitudinally along the drill pipe joint.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of U.S. patent application Ser. No. 13/710,644, filed on Dec. 11, 2012 (issued as U.S. Pat. No. 9,109,417 on Aug. 18, 2015), which claims benefit of U.S. Provisional Patent Application Ser. No. 61/665,110, filed Jun. 27, 2012, each of which are incorporated herein by reference and to which priority is hereby claimed. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable 
       REFERENCE TO A “MICROFICHE APPENDIX” 
       [0003]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    The present invention relates to a method and apparatus for cleaning a wellbore with specially configured drill string mounted tools. More particularly, the present invention relates to a tool apparatus that enables debris removal tools (e.g., scraper blades, brushes or magnetic members/magnets) to be mounted to the outer cylindrically shaped surface of a section or joint of a drill string/drill pipe with a specially configured locking clamp or clamps. 
         [0006]    2. General Background of the Invention 
         [0007]    The Drilling of an oil well typically requires the installation into the wellbore of steel walled casing. This casing is cemented into place to provide a gas tight seal between the overlapping casing strings and also between the casing and the formation or rock through which the well is drilled. Typical cementing practice requires the cement to be pumped from the surface area or wellhead down a string of internal tubing or down the inner most casing string and displaced through the bottom of the casing string into the casing annulus. This procedure may contaminate the inside of the casing wall or wellbore with the cement. After cementation is completed, it is often required to drill out cement and the associated cementation equipment (commonly referred to as shoe track, floats shoe, landing collar, and darts). 
         [0008]    Chemicals, solids, greases and other fluids used in the drilling process can and do adhere to the casing wall. These chemicals often mix to become a sticky and viscous substance which is largely resilient to chemical treatments and difficult to remove. As the wellbore casing is steel walled, it can and is prone to rusting and scaling. 
         [0009]    During the drilling and other downhole activities, pieces of the drilling or wellbore equipment may need to be milled. Through various other processes (purposeful or accidental), pieces or parts can be left inside the wellbore. The aforementioned situations result in contaminants being left in the wellbore, which will for the purposes of this document be referred to as debris. 
         [0010]    During the completion phase in a well lifecycle, several pieces of hardware are semi-permanently installed into the wellbore. These vary greatly in complexity and cost. Their primary function is the transportation of produced hydrocarbons (or injection from surface of other fluids) between the reservoir and the Christmas tree/wellhead (or vice versa) as well as maintaining hydrostatic control of the wellbore at all times. Completions typically include steel tubular piping to transport the fluids, at least one hydrostatic sealing device (packer) and one safety valve. More complex completions may include gauges to measure pressure and temperature at multiple points in the wellbore. Other items may include chokes, screens, valves and pumps. Advancements in downhole electronics make the placement of measuring and controlling equipment more accessible and more commonplace. 
         [0011]    Typically these components are sensitive to debris. It has been well documented that debris is a leading root cause of failure during completion operations. In response, a niche industry has developed since the late 1990s, which is focused on the removal of debris and the cleaning of the wellbore. This niche of the oil industry is known as wellbore cleanup. The wellbore cleanup operations will typically take place between the drilling and completion of the well. 
         [0012]    Generally speaking, the practice of wellbore cleanup is not new. Examples of prior art go back many years when basic embodiments of wellbore cleanup tools were developed, including scrapers, brushes, magnets, junk catchers and variations thereof. These were basic tools designed to fit a basic need, examples of which are still in use today. 
         [0013]    As advancements in drilling and completion technologies were made (particularly starting in the 1990&#39;s with the inclusion of downhole electronics, sand control, intelligent completions and extended reach drilling) improvements to the design and functionality of wellbore cleanup tools were marketed, and the practice of improving the cleanliness of oil wells prior to installation of the completion components became almost standard practice. During the wellbore cleanup operations, an assembly of tools (referred to as a bottom hole assembly or BHA) will be run into the wellbore to clean each casing section. These tools are fastened together using threaded connections located at either end of the tool. The tools or BHA are then fastened together with the drill string or work string consisting of multiple lengths of drill pipe, collars, heavy weight drill pipe, wash pipe or tubing also featuring threaded connections. These threaded connections are typically industry standard connections as defined in ANSI/API Specification 7-2 (for example 4½″ IF/NC50 or 3½″ IF/NC38) and commonly referred to as API connections. Also available are proprietary connections which are licensed from manufacturers of high strength drill pipe. Popular proprietary connections are supplied by NOV—Grant Prideco (eXtreme Torque, HI Torque, Turbo Torque), Hydrill (Wedge Thread) and others. The proprietary connections are often referred to as premium drill pipe connections and are typically used when higher mechanical strengths are required (e.g., torque, tensile strength, fatigue resistance, etc.) or when larger diameter drill pipe is preferred relating to the improvement of drilling hydraulics. For example, it is common now to use 5⅞″ OD drill pipe inside 9⅝″ casing to improve hydraulics whereas in the past it would have been more common to use 5″ drill pipe). 
         [0014]    The table below shows some examples of drill pipe and connection combinations used for a typical casing size; however, due to the many manufacturers and standards available, there may be thousands of combinations. 
         [0015]    Note: The Drill Pipe OD refers to the Pipe Body OD and not the maximum external of the component. The Tool Joints are always of larger diameter. Also the Casing Size is defined by the Nominal OD and the linear weight per foot. API  5 -CT allows for a tolerance in the diameter and ovality. Therefore the Casing ID may vary significantly. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
               
               
                   
                 Typical 
                   
                   
                   
               
               
                 Casing 
                 Nominal 
                 Drill Pipe 
                 Drill Pipe 
                 Drill Pipe 
               
               
                 Size OD 
                 Casing ID 
                 Connections 
                 OD 
                 Tool Joint OD 
               
               
                   
               
             
             
               
                 9.625″ 
                 8.374″ 8.921″ 
                 API NC50, 
                 5.0″ 
                 6.375″-6.750″ 
               
               
                   
                   
                 (4½)″ IF 
               
               
                 9.625″ 
                 8.374″ 8.921″ 
                 TT/HT/XT50 
                 5.0″ 
                 6.375″-6.750″ 
               
               
                 9.625″ 
                 8.374″ 8.921″ 
                 TT/HT/XT55 
                 5.5″ 
                 7.0″-7.375″ 
               
               
                 9.625″ 
                 8.374″ 8.921″ 
                 TT/HT/XT57 
                 5.875″ 
                 7.0″-7.375″ 
               
               
                 9.625″ 
                 8.374″ 8.921″ 
                 WT50 
                 5.0″ 
                 6.⅝″-7.0″ 
               
               
                 9.625″ 
                 8.374″ 8.921″ 
                 WT54 
                 5.5″ 
                 7″ 
               
               
                 9.625″ 
                 8.374″ 8.921″ 
                 WT56 
                 5.875″ 
                 7″-7¼″ 
               
               
                   
               
             
          
         
       
     
         [0016]    Wellbore cleanup tools come in a variety of types and brand names. However, they can be categorized generally as one of the following: a scraper, brush, magnet, junk basket, debris filter, circulation sub, drift or a combination of two or more of these. These tools shall typically consist of a tool body onto which the various components can be attached. The tool body may consist of one or more pieces, but shall in all cases include threaded drill pipe connections, either API or Premium type. The tool body is typically an integral drill string component when made up into the drill string and shall bear all the tensile, torque, fatigue and pressure loading of the drill string. The tool body is typically made of steel and customized to allow attachment of the various components in order for it to function in the manner described. 
         [0017]    Due to the many variations of drill pipe connections, the variety of casing sizes, and the many types of wellbore cleanup tools required, it would be commercially impractical for a company providing wellbore cleanup tools to stock every combination required from every customer. Therefore the practice of designing wellbore cleanup tools to cover a range of casing sizes as well as a variety of functions has become common practice, whereby the tool body can be used with interchangeable external components to cover both the size range and in some cases also to alter the function of the tool (for example from a scraper to a brush). This allows standardization of the tool body, however as the drill pipe connections are hard cut onto the tool body, a degree of standardization of the tool body connections are required. Typically this is the API drill pipe connection common to that casing size (NC50 for 9⅝″ casing or NC38 for 7″ casing). In some cases the wellbore cleanup tool manufacturer may supply the tools with premium drill pipe connections, however for commercial reasons this is usually limited to specific projects or markets where the use of the corresponding drill pipe justifies this. 
         [0018]    It is common for suppliers of wellbore cleanup tools to supply either individual tools or assemblies of tools where the individual tools have a type of drill pipe connection which is not the same as that used in the drill string. In this case it is common for the tools to be supplied with crossovers. Crossovers are typically short “subs” (joints of tubing) with differing connections at each end. For example, a XT-57 box thread can be at the top with an API NC50 pin at the bottom. This allows components of the drill string with non-interchangeable threaded end connections to be made up together into a singular integral drill string. Further to this, it is often practice to supply pup joints which are typically ten feet (10′) or less in length and have a profiled external diameter which matches the drill pipe and which fits into the drilling elevators and drill pipe slips to facilitate the installation and removal of the drill string into/from the wellbore in a timely fashion. There also exists pup-overs which are a combination of pup joint and crossover and which combines the functionality of both. 
         [0019]    Wellbore cleanup tools and drill string often have mismatching threaded connections, and the wellbore cleanup tools are usually rated to lower strengths. The lower strength of the cleanup tools in effect reduces the overall strength of the drill string, which is typically rated by the strength of its weakest link. This has become an acceptable practice provided the drilling parameters do not exceed the limitations of the weakest point. The situation can arise during the cleanup operations that high torque can be observed during rotation of the drill string which results in rotation of the string being suspended. Drill string rotation is a key function of wellbore cleanup in the removal of debris from the wellbore, the lack of which significantly impacts the efficiency and effectiveness of the wellbore cleanup. 
         [0020]    The requirement to include crossovers and pup joint into the drill string increases the number of threaded connections into the drill string which in turn increases the time and cost to deploy the drill string, increases the inspection costs and increases the likelihood of failure. The inventory of crossovers and pup joints needs to be managed, which includes storage, handling, inspections and maintenance Due to the many types of drill pipe connections and the varying sizes, and the need to maintain sufficient inventory for multiple overlapping operations, the stocking and management of these inventories is a cost prohibitive endeavor. 
       BRIEF SUMMARY OF THE INVENTION 
       [0021]    The apparatus of the present invention solves the problems confronted in the art in a simple and straightforward manner. 
         [0022]    The present invention provides an improved wellbore cleaning method and apparatus whereby wellbore cleanup tools perform the functions of a scraper, brush, magnet and wellbore filter. The tool apparatus of the present invention provides external mounting to the drill pipe cylindrical portion in between the pipe “pin” and “box” end portions and securely attached by a special method and configuration which prevents the tools from being accidentally removed during the wellbore cleanup operations. 
         [0023]    Drill pipe joints provide a solid tubular body with uniform diameter and external ‘tool joints’ (i.e., pin and box) of larger diameter which contain the threaded connections. Since the tools are mounted externally to the drill pipe, there are no tool bodies as such, and therefore there is no reduction in the drill string strength through the introduction of a tool body, crossover, pup joint, and drill pipe connection. This arrangement eliminates the need to maintain an inventory of crossovers or to have stock of tool bodies with multiple threaded connections. 
         [0024]    The wellbore cleanup tools of the present invention are designed with the principal that if one component were to fail, it would not result in the equipment coming loose from the drill pipe and being left in the wellbore. 
         [0025]    In one embodiment the tool internal components are split longitudinally and bolted together about the drill pipe. Robust external rings of single piece construction and with robust internal threads are mated to the split internal components. This external ring covers the aforementioned bolts to prevent them from loosening. The external ring is prevented from loosening by two methods. First, the thread is orientated in such a way that rotating the drill pipe in the conventional manner (clockwise) will tighten the thread due to the friction of the tool against the casing. Secondly grub screws are backed out into internal pockets and secured with springs which prevent any movement of the external ring once secured. This arrangement works positively with the resultant centrifugal forces imparted during rotation of the string. 
         [0026]    The tool designs of the present invention are modular and can be deployed individually or in any combination as required by a user or customer. The tools are mounted to the drill pipe body only radially and are free to rotate or move longitudinally along the pipe. They could not move past a tool joint (pin or box end) due to the larger external diameter. There can also be included in the present invention a locking device which consists of a set of toothed dogs, external threaded rings, and an internal split type clamp. When fully made up, the teeth grip the drill pipe, preventing any longitudinal movement. The purpose of this arrangement is to allow mounting of the locking device at any location on the drill pipe. This location may be above or below the mountable wellbore cleanup tools and be designed to limit the longitudinal movement of these tools which the drill string is being moved in the wellbore. 
         [0027]    Prior art wellbore cleanup tools typically include drill pipe connections at either end, and have particular components allowing the tools to perform their designed actions, such as a scraper, brush, magnets, junk sub, debris filter or a combination thereof. In the prior art, it is common practice to deploy several such tools screwed together end on end, and it is also common to include crossovers, due to frequent incompatibility between the wellbore cleanup tool connections and the drill pipe connections. To reduce handling time on the rig floor while picking up and laying down such equipment, the installation of pup joints and/or handling pups is also common practice. 
         [0028]    The main disadvantages to the above prior art systems are as follows:
       Drill String Integrity—a drill string can be analogized as being similar to a chain, being only as strong as its weakest link:
           Introducing connections which are not the same as the drill string compromises the mechanical integrity of that string. Most wellbore cleanup tools are designed with API connections, which are typically of lower mechanical strength than premium drill pipe connections. As such, introducing the required crossovers to the string reduces the overall strength of the string.   Many such tools include internal connections, which introduces another element of risk to overall drill string integrity. These internal connections are typically non-standard (do not conform to API).   Drill pipe connections are typically made from a high strength steel, typically of higher strength than the wellbore cleanup tools.   An important factor in prevention of fatigue failures of the drill string are bending strength ratios of the string and the connections. Adding additional wellbore cleanup tools as integral components may result in sub-optimal bending strength ratios at critical connections reducing the overall drill string integrity.   Rig Time—the daily operational costs of running a rig are one of the most significant cost impacts in drilling operations. Saving rig time reduces the overall cost of drilling a well, and those involved in this business know the importance the drilling operators place on time management.   Drilling rigs are designed generally to run drill pipe in an efficient manner. There are many examples of prior art where technology has been adapted or improved to reduce the time to handle the drill pipe on the drilling rig, including automated systems for handling the pipe, and for making and breaking connections.   Drilling rigs are generally not well adapted to running individual tools, whether they be wellbore cleanup tools or other types, as they are of non-standard lengths and shapes. With the assistance of pulleys, cranes and winches, these are manhandled onto the rig floor and made up either individually or in short pre-made sub-assemblies. This is generally a time-consuming practice and there is also an impact on the safety of the individuals running the equipment as they are exposed to manual handling of heavy equipment, pressure, dropped objects and other hazards typical of a rig floor.
 
Prior art methods of installation of prior art wellbore cleanup tools typically involve the following steps:
   
               
 
         [0037]    1. Placement or ‘layout’ of the required tools onto the ‘catwalk’ (temporary storage place for drill pipe and equipment being run into or pulled out of the wellbore) using slings, cranes, and/or forklifts. Risks include exposure to dropped objects and accidental crushing from working in proximity to heavy moving equipment. 
         [0038]    2. Installation of lifting subs or handling pups to the individual tools and/or making the tools into small sub-assemblies to reduce handling time of the rig. Risks include manual handling of heavy equipment with injuries to fingers and toes. 
         [0039]    3. Lifting the sub-assemblies and/or tools to the rig floor using the crane, tugger lines (winches) and/or forklifts. Risks include exposure to dropped objects. 
         [0040]    4. In the case that the tools are already made into a completed assembly with pup joints that are of the correct type, it may be possible to install the pup joint directly into the drill pipe elevators and by use of the crane/tugger lines and other devices lift the entire assembly and make it up into the drill string. 
         [0041]    5. More commonly the tools and sub-assemblies will be picked up individually. Typically one or more joints of drill pipe (or drill collars) will be suspended in the elevators with the lower pin connection around shoulder height on the rig floor. Alternatively a ‘lifting sub’ may be suspended in the elevators which has an external upset and a pin connection facing down typically compatible with the tools which shall be suspended from it. 
         [0042]    6. Depending on the design of the BHA and drill string, there may be either drill pipe, or drill collars suspended from the rotary table by slips. The use of either type requires specialized ‘slips’ and possibly the installation of a ‘dog collar’ (a safety device designed to catch the string should the drill collar slips fail). There may be no lower string, in which case a bit or mill will be installed at the end of the wellbore cleanup BHA. 
         [0043]    7. The sub-assemblies or tools are picked up one at a time using winches and the connections made up manually to the drill string. This is a time consuming process which involves the manual use of chain/strap wenches, pipe wenches, drill collar slips, dog collars and hammers. Each connection is also ‘torqued’ using either the semi-manual pipe tongs or using an automated unit such as a ‘mechanical rough neck’ before being lowered into the wellbore. 
         [0044]    8. This process presents a risk to personnel as it involves multiple persons working with heavy equipment in close proximity. Drill pipe tongs and associated equipment are notorious for causing injuries to fingers while being used or causing crushing injuries when being handled or swinging free. 
         [0045]    9. A further risk is accidental dropping of the string during make-up. Most tools typically come with ‘slick’ tool joints (no external upset) and are often shorter than ideal to allow safe installation of the drill collar type slips and the necessary dog collar. Drill collar slips rely on friction to suspend the drill string and are typically less reliable than drill pipe slips which suspend the string from an upset. If the drill collar were to fail and the dog collar not to hold, then the string would be dropped and free-fall into the wellbore resulting in a costly retrieval (fishing) operation. 
         [0046]    Drilling operations are often conducted in remote locations, whether on land, or at sea. Often drilling may take place in countries with limited operational support bases, requiring equipment to be transported to and from the rig over vast distances requiring the use of air, land and sea transportation. Compounding this issue, downhole oilfield equipment tends to be elongated and heavy, requiring specialized baskets to deliver the equipment to the rig site as well as special boats with large deck space. These baskets can be as long as 40 ft. Furthermore, transportation of equipment by air is expensive due to length and weight of equipment and there is typically a premium to be paid to transport such equipment. Offshore drilling rigs have limited deck space to store equipment and minimizing the use of deck space is important to efficient operations. Servicing of the equipment at a logistics base is a labor intense process and requires specialized equipment, trained operators as well as access to third party inspectors. 
         [0047]    The application of the invention in the method outlined in the following steps mitigates, eliminates or improves the problems listed above in the following manner. 
         [0048]    1. Drill String Integrity—The wellbore cleanup tools as disclosed are externally mounted and secured to the drill pipe without the use of tool bodies. The drill string integrity remains intact as there are no inclusions of additional integral components and therefore no reduction in the integrity of the drill string. 
         [0049]    2. Rig Time—The wellbore cleanup tools can be mounted to a single joint of drill pipe at the rig site. This action can be completed on the deck or catwalk away from the main area of operation. When required to be run in the hole, the single joint can be picked up to the rig floor either using the rig&#39;s automated systems or in the same manner as running a single joint from the catwalk or mouse-hole which would be the same method used when picking up single joints of drill pipe. It would also be possible to rack the joint in the derrick as part of a stand of pipe in the same manner as the other drill pipe stands are racked. 
         [0050]    3. Logistics—As the wellbore cleanup tools do not have tool bodies, and are not required to be made into sub-assemblies prior to shipping, it is possible to ship them in short containers, without the need for the elongated basket typically used to ship other types of tools. This reduces the burden on the deck space onboard the rigs, supply boats and trucks. Furthermore, it reduces the cost of air transportation as the shipping boxes are no longer required to be elongated. 
         [0051]    4. Safety—The use of this technology eliminates the need to perform single or sub-assembly pickups on the rig floor, which reduces exposure to common hazards of working on a rig floor such as finger injuries and crushing injuries while using the manual and semi-automated tools and equipment. 
         [0052]    The following method describes the general application of one embodiment of attaching a mountable wellbore cleanup tool of the present invention to a joint of drill pipe on a rig location. 
         [0053]    1. Begin with a single joint or section of drill pipe which is identical to the joints of drill pipe that comprise the drill string which is to be deployed in the wellbore. 
         [0054]    2. Attach a support sleeve, which consists of two or more mated and largely identical pieces split longitudinally, about the drill pipe. These pieces when mated shall make a complete concentric part. The support sleeve can have an internal diameter slightly larger than the external diameter of the drill pipe body to permit rotation of the support sleeve relative to the drill pipe. The internal diameter of the support sleeve can be less than the external diameter of the drill pipe tool joints, such that the support sleeve can be abutted against the tool joint to limit the longitudinal movement of the support sleeve relative to the drill pipe. 
         [0055]    3. The pieces of the support sleeve are mated using bolts, pins, hinges, or similar screw type fasteners. Depending on the configuration of the tools, either scraper, brush or magnetic elements may be attached to the support sleeve. 
         [0056]    4. Typically the fasteners which secure the support sleeve together may not be of sufficient strength alone to prevent accidental detachment of the support sleeve downhole with disastrous effect. It is therefore necessary to install a plurality of centralizer rings to the support sleeve, which are to be inserted (slide) over the ends of the drill pipe tool joints. These centralizer rings can be of singular piece construction for strength. The internal diameters of the centralizer rings can be slightly larger than the external diameter of the drill pipe tool joints. The centralizer rings can be threaded internally and mated to an external thread on the support sleeve. Alternatively they may be secured to the support sleeve using bolts, pins, or screws and a combination of these fasteners/methods. Once installed, the centralizer rings shall completely or partially cover the fasteners used to mate the support sleeve pieces (e.g. halves) to prevent them from accidentally being removed. 
         [0057]    5. To prevent the support sleeve and the assembled components from traveling longitudinally relative to the drill pipe it is necessary to install a locking clamp assembly. Once installed, the support sleeve and assembled components shall abut against the locking clamp at one end and can abut against a drill pipe tool joint at the other, thus preventing any longitudinal movement relative to the drill pipe. Alternatively, two locking clamps can be used to secure the support sleeve and assembled components. 
         [0058]    6. To install the locking clamp to the drill pipe, the split slip ring is installed about the drill pipe body. This consists of a plurality of near identical pieces which when mated together make a concentric component. The internal diameter of the split slip ring is slightly larger than the drill pipe body to allow it to be installed and moved into position. The split slip ring pieces are mated using bolts, pins, hinges or similar screw type fasteners. 
         [0059]    7. A plurality of slip segments are installed into or adjacent to the split slip ring. The slip segments have an internal profile which matches the external diameter of the drill pipe body and includes a toothed or serrated surface which engages the drill pipe body and prevents longitudinal and rotational movement once sufficient collapsing force is applied. The external profile of the slip segments is conical such that when a mated external component applies a longitudinal force, this conical section converts this force into a collapsing force using the mechanical advantage of the conic shape. 
         [0060]    8. A plurality of slip cone rings are installed over the slip segments with an internal conical mating profile to engage the slip segment. 
         [0061]    9. To complete the installation of the locking clamp, a tensioner sleeve is slid over the drill pipe tool joints and engaged by a thread to the split slip ring. This can be of singular piece construction. As the tensioner sleeve thread is tightened, it drives the slip cone rings longitudinally which in turn engage the slip segments, which in turn engage the drill pipe body. The tensioner sleeve internal diameter is slightly larger than the drill pipe tool joints to allow installation from one end. 
         [0062]    10. The drill pipe single joint complete with installed mountable wellbore cleanup tool can then be picked up to the rig floor by whatever methods are employed upon that particular rig. This may include laying the single joint on the catwalk, placing it in the mouse-hole, making it up to a stand, or racking it in the derrick. 
         [0063]    11. After completion of the wellbore cleanup operations, the installation process is reversed. The components can be stored back in their box for later operations or returned to the supply base. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0064]    For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
           [0065]      FIG. 1  is an elevation view of a normal drilling operation showing the handling of drill pipe; 
           [0066]      FIGS. 2-4  are elevation views illustrating the method of the present invention and showing the mountable wellbore cleanup tool apparatus of the present invention as part of drilling operations; 
           [0067]      FIG. 5  is a perspective view of the preferred embodiment of the apparatus of the present invention; 
           [0068]      FIG. 6  is an exploded perspective view of the preferred embodiment of the apparatus of the present invention; 
           [0069]      FIG. 7  is a partial sectional elevational view of the preferred embodiment of the apparatus of the present invention; 
           [0070]      FIG. 8  is a sectional view taken along lines E-E of  FIG. 7 ; 
           [0071]      FIG. 9  is a sectional view taken along lines F-F of  FIG. 7 ; 
           [0072]      FIG. 10  is a sectional view taken along lines G-G of  FIG. 7 ; 
           [0073]      FIG. 11  is a partial perspective view of the preferred embodiment of the present invention showing a centralizer ring; 
           [0074]      FIG. 12  is a partial exploded perspective view of the preferred embodiment of the apparatus of the present invention showing a locking clamp; 
           [0075]      FIG. 13  is a perspective view of the locking clamp of  FIG. 12 ; 
           [0076]      FIG. 14  is a sectional view of the locking clamp portion of the preferred embodiment of the apparatus of the present invention; 
           [0077]      FIG. 15  is a sectional view taken along lines A-A of  FIG. 13 ; 
           [0078]      FIG. 16  is an exploded perspective view of the preferred embodiment of the apparatus of the present invention showing the debris removing tool in the form of a mountable scraper; 
           [0079]      FIG. 17  is an exploded perspective view of the preferred embodiment of the apparatus of the present invention illustrating a mountable scraper tool; 
           [0080]      FIG. 18  is a perspective view of the mountable scraper tool of  FIGS. 15 and 16 ; 
           [0081]      FIG. 19  is a sectional view of the mountable scraper tool of  FIGS. 16 through 18 ; 
           [0082]      FIG. 20  is a sectional view taken along lines A-A of  FIG. 19 ; 
           [0083]      FIG. 21  is a sectional view taken along lines B-B of  FIG. 19 ; 
           [0084]      FIG. 22  shows a perspective view of a preferred scraper broach; 
           [0085]      FIG. 23  shows various broach arrangements; 
           [0086]      FIG. 24  is a perspective view showing a brush type broach; 
           [0087]      FIG. 25  is a sectional view showing a broach concentric ID construction; 
           [0088]      FIG. 26  is a sectional view showing a broach eccentric broach construction; 
           [0089]      FIG. 27  is an exploded perspective view of the preferred embodiment of the apparatus of the present invention showing a mountable brush tool; 
           [0090]      FIG. 28  is a perspective view of the preferred embodiment of the apparatus of the present invention showing a mountable brush tool; 
           [0091]      FIG. 29  is a sectional view of the mountable brush tool of  FIGS. 27 and 28 ; 
           [0092]      FIG. 30  is a sectional view taken along lines C-C of  FIG. 29 ; 
           [0093]      FIG. 31  is a sectional view taken along lines D-D of  FIG. 29 ; 
           [0094]      FIG. 32  is a sectional view showing an alternate embodiment where the centralizers are an integral component of the split housing; 
           [0095]      FIG. 33  is another alternate embodiment with free rotating centralizers and different locking methods; 
           [0096]      FIG. 34  is a sectional view showing an alternate centralizer that is attached with grub screws; 
           [0097]      FIG. 35  is a sectional view showing centralizers attached with a spline; 
           [0098]      FIGS. 36A-36C  are sectional views showing various secondary attachment methods; 
           [0099]      FIGS. 37A-37C  are sectional views showing various brush insert attachment methods; 
           [0100]      FIG. 38  is a sectional view showing a generic mountable well brush cleanup tool having a split housing; 
           [0101]      FIG. 39  is a sectional view showing a cleanup tool having a hinged housing; 
           [0102]      FIG. 40  is an end view showing a cleanup tool having a hinged housing; and 
           [0103]      FIG. 41  is a sectional view of a wellbore cleanup tool having a customized tool mandrel. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0104]      FIGS. 1-10  show the preferred embodiment of the apparatus of the present invention designated generally by the numeral  20  (see for example,  FIGS. 2 ,  6 ).  FIGS. 1-4  illustrate the method of the present invention. In  FIGS. 1-4 , a derrick  1  is shown having a block  2  and elevator  3 . The derrick  1  can be provided with a tugger line  4 . In  FIGS. 1-3  there is shown a rotary table with slips designated by the numeral  5 . Finger boards  6  and mouse hole  7  can be used to store individual drill pipe joints or sections  12 . A mouse hole  7  can be used to store a drill pipe joint  12  that can then be lifted using tugger line  4  as shown in  FIG. 1 . Individual joints of drill pipe  12  are stored on catwalk  9 . These joints  12  can be moved as indicated by arrows  13 ,  14  to Vee door  8  and then to the derrick platform  17 . In  FIGS. 1-4 , a wellbore  10  is shown. Drill string  11  is shown being lowered into wellbore  10 . The drill string  11  is comprised of drill pipe joints  12  connected end to end. In  FIG. 1 , the drill string  11  is supported by the rotary table with slips  5 . 
         [0105]    The tool apparatus  20  provides a tool assembly  15  which can be mounted to a standard, commercially available drill pipe joint or section  12  as will be described more fully hereinafter. In  FIG. 1 , arrows  13 ,  14  illustrate the travel of a drill pipe joint or section  12  from catwalk  9  to platform  17 .  FIGS. 2 ,  3  and  4  illustrate the travel path of a joint of drill pipe  12  fitted with tool assembly  15  as it travels from catwalk  9  ( FIG. 2 ) to the platform  17  (see  FIG. 3 ) and into the wellbore  10  (see  FIG. 4 ). In  FIG. 4 , the tool assembly  15  mounted on a drill pipe joint or section  12  is shown as part of the drill string  11 .  FIG. 3  illustrates that the tool apparatus  20  (which includes the tool assembly  15  and a joint of drill pipe  12 ) can be placed in the mouse hole  7 , or finger boards  6 , or gripped by the block  2  and elevator  3  or placed in the mouse hole  7  prior to being lowed into wellbore  10 . 
         [0106]      FIGS. 5-10  show tool assembly  15  and tool apparatus  20  in more detail. The tool apparatus  20  is shown in  FIGS. 5-10  with tool assembly  15  mounted to drill pipe joint or section  12  and more particularly to the cylindrically shaped portion  23 , which has a cylindrical outer surface  24 . Each drill pipe joint or section  12  can provide connector end portions  21 ,  22  such as a pin end portion  21  and a box end portion  22 . In between the pin end portion  21  and the box end portion  22  is cylindrical portion  23  having cylindrically shaped outer surface  24  to which tool assembly  15  is attached. 
         [0107]    In one embodiment, tool assembly  15  can be mounted to cylindrical portion  23  in between a connector end portion  21 ,  22  and a locking clamp  28  (see  FIG. 5 ). However, it should be understood that the tool assembly  15  could be mounted in between a pair of locking clamps  28  which are both spaced away from either connector end portion  21  or  22 . 
         [0108]    Tool assembly  15  provides a support sleeve  25 . The support sleeve  25  has sleeve halves  26 ,  27  (see  FIGS. 7-11 ). Centralizer rings  29  are provided at each end portion of support sleeve  25  and attached thereto with threaded connections  31 . The sleeve halves  26 ,  27  can be connected together using bolts or bolted connections  30 . In  FIG. 7 , split bearings  32  are shown attached to each end portion of support sleeve  25 . Compression springs  33  are provided in between support sleeve  25  and centralizer ring  29  at each end portion of tool assembly  15 . One or more recesses or sockets  34  are provided in between each centralizer ring  29  and support sleeve  25 . These recesses or sockets  34  are receptive of conical spring  36  and grub screw  35 . The grub screw  35  can be tightened to occupy recess or socket  34  of sleeve  25 . 
         [0109]    Once centralizer ring  29  is threaded upon the external threads  37  of support sleeve  25 , a threaded connection  31  is perfected between centralizer ring  29  and support sleeve  25 . Grub screw  35  is spring loaded using conical spring  36 . After the threaded connection  31  is perfected, the grub screw  35  can be backed out slightly to engage a correspondingly shaped recess or socket  43  on centralizer ring  29  (see  FIGS. 7 ,  11 ). The threaded connection  31  is thus perfected by engaging the external threads  37  of sleeve  25  with the internal threads  38  of centralizer ring  29 . 
         [0110]    A plurality of magnets  40  are mounted to magnet spacers  41  and magnet internal support sleeve  39 . The support sleeve  25  has minimal thickness sections  42  that cover the magnets  40  as shown in  FIG. 9 . 
         [0111]      FIGS. 13-18  show locking clamp  28  in more detail. Locking clamp  28  has a plurality of slip segments  45  that are circumferentially spaced around pipe joint  12  cylindrical portion  23 . A split cone ring  46  provides two portions that engage and surround the plurality of slip segments  45  as shown in  FIGS. 13 ,  15  and  17 . A split slip ring  47  can be a two part ring that forms a connection at interlocking connection  56  with each slip segment  45 . Thus, each slip segment  45  is installed into a mating groove of the split slip ring  47  as shown. Bolted connections or bolts  48  connect the segments  53 ,  54  of the split slip ring  47  together. Each of the segments  53 ,  54  has openings  55  that receive bolts or bolted connections  48  and internally threaded openings  60  that engage the threaded end portion of a bolt  48  as shown in  FIGS. 13-14 ,  16  and  18 . 
         [0112]    A snap ring  49  is placed in between split slip ring  47  and tensioner sleeve  50 . Annular grooves can be provided on the outside surface of split slip ring  47  and on the inside surface of tensioner sleeve  50 . In  FIG. 13 , the numeral  63  designates the annular groove on the outside surface of each segment  53 ,  54  of split slip ring  47 . In  FIG. 12 , the numeral  64  designates the annular groove  64  on the inside surface of tensioner sleeve  50 . 
         [0113]    Each of the slips or slip segments  45  has an inner toothed portion  51  that grips the cylindrical outer surface  24  of cylindrical portion  23  of drill pipe joint  12 . A gap  52  is provided in between each of the slip segments  45  (see  FIG. 12 ). A threaded connection  57  is formed between the external threads  58  of split slip ring  47  and the internal threads  59  of tensioner sleeve  50 . Correspondingly shaped and sized annular shoulders are provided on split cone ring  46  and tensioner sleeve  50 . In  FIG. 14 , split cone ring  46  has annular shoulder  61 . Tensioner sleeve  50  has annular shoulder  62 . 
         [0114]      FIGS. 16-22  show a scraper or broach tool designated generally by the numeral  65 .  FIG. 22  shows perspective views of a scraper broach  70 . As with the preferred embodiment, the scraper tool  65  provides a support sleeve  66  which can be a split support sleeve having sleeve halves  67 ,  68 . External split bearings  69  attach to the support sleeve  66  as shown in  FIGS. 22 and 25 . Centralizer rings  29  connect to the support sleeve  66  with threaded connections as with the preferred embodiment. The support sleeve  66  thus provides external thread  71  (see  FIG. 17 ). The centralizer rings  29  provide internal threads  38  (see  FIG. 11 ). A scraper or broach  70  is a cleaning member that attaches to the outer surface of support sleeve  66 , being held in position by the centralizer rings  29  which overlap it as seen in  FIGS. 22 and 25 . C-rings  72  are provided in between support sleeve  66  and centralizers  29  as shown. Also provided between centralizer rings  29  and support sleeve  66  are spring support ring  78  and compression spring  75 . As with the preferred embodiment, grub screws  35  and conical springs  36  can be used to complete the connection between the centralizer ring  29  and support sleeve  66 . External split bearings  69  form an interlocking connection with support sleeve  66  at interlocking connection  76 . Snap ring  77  can be placed in between external split bearing  69  and centralizer  29 . 
         [0115]    Pins  74  attaches to sleeve  66  and to broach or scraper  70  as shown in  FIGS. 19 through 22 . Pins  74  attached to corresponding holes  93  on scraper broach  70 . Pins  74  are attached to the support sleeve  66  by welding and become an integral part of the support sleeve  66 . 
         [0116]      FIGS. 22-26  show various scraper and brush type broaches. In  FIG. 24 , three different configurations of longitudinal cuts are shown for a broach  89 . These can include helical longitudinal cut  90 , straight longitudinal cut  91  and tortuous longitudinal cut  92 .  FIG. 24  shows a brush type broach  89 .  FIG. 25  illustrates a concentric ID for the broach  89  whereas  FIG. 26  shows an eccentric ID for the broach  89 . In  FIG. 22 , the broach  89  is shown having a mating hole  93  for a pin  74 , scraper teeth  94  and helical bypass grooves  95 . The longitudinal cut  90  is shown in  FIG. 22 . However, it should be understood that the  FIG. 22  configuration could have the straight longitudinal cut  91  or the tortuous longitudinal cut  92  of  FIG. 23 . 
         [0117]      FIGS. 27-31  show a brush tool  80  that can be used to brush the wellbore. Brush tool  80  provides a support sleeve  81  that has a helical split  87  as shown in  FIG. 27 . Support sleeve  81  has split bearings  82  at its end portion (see  FIG. 29 ). Each end portion of support sleeve  81  has external threaded sections  86  for forming a connection with a centralizer ring  29  as with the earlier embodiments (see  FIG. 27 ). Grub screws  35  and conical springs  36  can be used to form a connection between the support sleeve  81  and centralizer ring s  29  as shown in  FIGS. 23 and 25 . Compression spring  83  is placed in between centralizer ring  29  and sleeve  81  at interlocking connection  88  which can be in the form of correspondingly shaped annular shoulders provided on both the sleeve  81  and centralizer  29 . Compression spring  83  is provided in between the annual shoulders at the interlocking connection  88  as shown in  FIG. 29 . 
         [0118]    A plurality of brush segments  84  are mounted to support sleeve  81  at provided mating grooves  85  (see  FIGS. 28 and 29 ). 
         [0119]      FIG. 32  provides a sectional view of a wellbore cleaning tool having integral centralizers which are non-rotating. The well cleaning tool  96  of  FIG. 32  is shown mounted to drill pipe section  12 . The well cleaning tool  96  provides a split housing or split support sleeve  97  having integral centralizers  98 . Cleaning members  99 , such as a brush, scraper and/or magnet are mounted to the split housing or support sleeve  97 . External rings  100  are provided. The split housing or split support sleeve  97  is placed on drill pipe  12  in between locking clamps  28 . 
         [0120]      FIG. 33  shows an additional embodiment of the apparatus of the present invention which provides free rotating centralizers or centralizer rings  103 . Well cleaning tool  101  has a split housing  102  to which is affixed cleaning members  104 . Bolted connections  30  can be used to secure the halves of the split housing together as with the preferred and other embodiments. The centralizer rings  103  engage the outer surface of the split housing  102  and are held in position with a locking ring  105  or  106 . The locking ring  105  is a threaded type that engages threads provided on the split housing  102 . The locking ring  106  is a lock wire type. Cleaning members  99 , such as a brush, scraper and/or magnet are mounted to the split housing or support sleeve  97 . 
         [0121]      FIG. 34  shows a well cleaning tool designated generally by the numeral  110 . The well cleaning tool  110  provides centralizers that are attached with grub screws  35 . In  FIG. 34 , split housing  111  carries cleaning members  112 . External rings  113  are secured to split housing  111  using grub screws  35  and conical springs  36 . Split housing  111  can provide a recess or socket portion  114  that aligns generally with the recessed or socket portion  115  on external ring  113 . The aligned recesses or sockets  114 ,  115  can be occupied with a grub screw  35  and conical spring  36 . 
         [0122]      FIG. 35  shows a well cleaning tool  116  wherein centralizers are attached with a spline. In  FIG. 35  there is provided well cleaning tool  116  which has a split housing  117  that carries a plurality of cleaning members  118 . External centralizer rings  119  are attached to split housing  117  with splines  120 . Locking clamps  28  are placed on either side of split housing  117  to maintain its position upon drill pipe joint  12 . 
         [0123]      FIGS. 36A through 36C  show a well cleaning tool  121  with various secondary attachment methods.  FIG. 36A  shows a version of the secondary attachment method of the external ring to the slip housing using grub screws.  FIG. 36B  shows a version of the secondary attachment method of the external ring to the slip housing using a snap ring.  FIG. 36C  shows a secondary attachment method of the external ring to the slip housing using a locking ring and lock wire. In  FIGS. 36A ,  36 B, and  36 C there are seen split housing  123 , external rings  122 , cleaning members  124  and locking clamps  28 . Bolted connections  30  are also shown for holding the locking clamp  28  to the drill pipe  12  as well as for securing the split housing  123  to the drill pipe  12 . 
         [0124]    In  FIG. 36A , the secondary attachment method is in the form of grub screws  35 . The grub screws  35  can be provided with conical springs  36 . 
         [0125]    In  FIG. 36B , the secondary attachment method of the external ring  122  to the slip housing  123  using a snap ring  125 . 
         [0126]    In  FIG. 36C , the second method of attaching the external ring to the slip housing uses a locking ring and lock wire  126 . 
         [0127]      FIGS. 37A through 37C  show various brush insert and attachment methods on a well cleaning tool  130 . In  FIG. 37A , a dove tail groove and crimped style brush insert is shown designated as  131 . In  FIG. 37B , a crimped bullet style brush insert is designated by the numeral  132 . In  FIG. 37C , a stuffed style brush insert is shown, designated by the numeral  133 . In each of the  FIGS. 37A ,  37 B, there can also be seen locking clamp  28 , a split housing  134  and external centralizer rings  135 . It should be understood that any of the brush inserts of  FIGS. 37A ,  37 B,  37 C can be used with any embodiment of the brush tool. 
         [0128]      FIG. 38  shows a generic mountable wellbore cleaning tool designated by the numeral  140 . The well cleaning tool  140  provides a split housing  141 , cleaning member or members  142 , external rings  143 , locking clamps  28  and bolts or bolted connections  30 . 
         [0129]      FIGS. 39 and 40  show the well cleaning tool that provides a hinged housing. Well cleaning tool  145  is attached to a section of drill pipe  12  using split housing  146  that includes a pair of halves  147 ,  148 . The split housing halves  147 ,  148  are pivotally attached at hinge  149  and are connectable using bolted connections  30 . As with other embodiments, the well cleaning tool  145  provides cleaning members  150 , external rings  151 , bolted connections  30 , and locking clamps  28 . 
         [0130]      FIG. 41  shows a well cleaning tool  155  that is shown attached to a customized tool mandrel  156 . In  FIG. 50  there is provided tool mandrel  156  holding split housing  157 . Shown on split housing  157  are cleaning members  158  and external rings  159 . 
         [0131]    The following is a list of Reference Numerals used in the present invention: 
         [0000]    
       
         
               
             
               
               
             
               
               
             
           
               
                   
               
               
                 LIST OF REFERENCE NUMERALS: 
               
             
          
           
               
                 REFERENCE NUMBER 
                 DESCRIPTION 
               
               
                   
               
             
          
           
               
                 1 
                 derrick 
               
               
                 2 
                 block 
               
               
                 3 
                 elevator 
               
               
                 4 
                 tugger line 
               
               
                 5 
                 rotary table with slips 
               
               
                 6 
                 finger boards 
               
               
                 7 
                 mouse hole 
               
               
                 8 
                 Vee door 
               
               
                 9 
                 catwalk 
               
               
                 10 
                 wellbore 
               
               
                 11 
                 drill string 
               
               
                 12 
                 drill pipe joint/section 
               
               
                 13 
                 arrow 
               
               
                 14 
                 arrow 
               
               
                 15 
                 tool assembly 
               
               
                 16 
                 arrow 
               
               
                 17 
                 platform 
               
               
                 18 
                 arrow 
               
               
                 19 
                 arrow 
               
               
                 20 
                 tool apparatus 
               
               
                 21 
                 pin end portion/connector end portion 
               
               
                 22 
                 box end portion/connector end portion 
               
               
                 23 
                 cylindrical portion/connector end portion 
               
               
                 24 
                 cylindrical outer surface 
               
               
                 25 
                 support sleeve 
               
               
                 26 
                 sleeve half 
               
               
                 27 
                 sleeve half 
               
               
                 28 
                 locking clamp 
               
               
                 29 
                 centralizer ring 
               
               
                 30 
                 bolt/bolted connection 
               
               
                 31 
                 threaded connection 
               
               
                 32 
                 split bearing 
               
               
                 33 
                 compression spring 
               
               
                 34 
                 recess/socket 
               
               
                 35 
                 grub screw 
               
               
                 36 
                 conical spring 
               
               
                 37 
                 external threads 
               
               
                 38 
                 internal threads 
               
               
                 39 
                 magnet internal support sleeve 
               
               
                 40 
                 magnet 
               
               
                 41 
                 magnet spacer 
               
               
                 42 
                 minimal thickness section 
               
               
                 43 
                 socket/recess/bolt hole 
               
               
                 44 
                 bypass slot 
               
               
                 45 
                 slip segment 
               
               
                 46 
                 split cone ring 
               
               
                 47 
                 split slip ring 
               
               
                 48 
                 bolt/bolted connection 
               
               
                 49 
                 snap ring 
               
               
                 50 
                 tensioner sleeve 
               
               
                 51 
                 toothed portion 
               
               
                 52 
                 gap 
               
               
                 53 
                 segment 
               
               
                 54 
                 segment 
               
               
                 55 
                 opening 
               
               
                 56 
                 interlocking connection 
               
               
                 57 
                 threaded connection 
               
               
                 58 
                 external threads 
               
               
                 59 
                 internal threads 
               
               
                 60 
                 internally threaded opening 
               
               
                 61 
                 annular shoulder 
               
               
                 62 
                 annular shoulder 
               
               
                 63 
                 annular groove 
               
               
                 64 
                 annular groove 
               
               
                 65 
                 scraper tool 
               
               
                 66 
                 support sleeve 
               
               
                 67 
                 sleeve half 
               
               
                 68 
                 sleeve half 
               
               
                 69 
                 external split bearing 
               
               
                 70 
                 scraper/broach 
               
               
                 71 
                 external thread 
               
               
                 72 
                 C-ring 
               
               
                 73 
                 split bearing 
               
               
                 74 
                 pin 
               
               
                 75 
                 compression spring 
               
               
                 76 
                 interlocking connection 
               
               
                 77 
                 snap ring 
               
               
                 78 
                 spring support ring 
               
               
                 79 
                 annular end portion 
               
               
                 80 
                 brush tool 
               
               
                 81 
                 support sleeve 
               
               
                 82 
                 split bearing 
               
               
                 83 
                 compression spring 
               
               
                 84 
                 brush segment 
               
               
                 85 
                 mating groove 
               
               
                 86 
                 external thread 
               
               
                 87 
                 helical split 
               
               
                 88 
                 interlocking connection 
               
               
                 89 
                 broach 
               
               
                 90 
                 helical longitudinal cut 
               
               
                 91 
                 straight longitudinal cut 
               
               
                 92 
                 tortuous longitudinal cut 
               
               
                 93 
                 hole 
               
               
                 94 
                 scraper teeth 
               
               
                 95 
                 helical bypass groove 
               
               
                 96 
                 well cleaning tool 
               
               
                 97 
                 split housing/support sleeve 
               
               
                 98 
                 integral centralizer 
               
               
                 99 
                 cleaning member 
               
               
                 100 
                 external ring 
               
               
                 101 
                 well cleaning tool 
               
               
                 102 
                 split housing 
               
               
                 103 
                 centralizer ring 
               
               
                 104 
                 cleaning member 
               
               
                 105 
                 locking ring, threaded type 
               
               
                 106 
                 locking ring, lock wire type 
               
               
                 110 
                 well cleaning tool 
               
               
                 111 
                 split housing 
               
               
                 112 
                 cleaning member 
               
               
                 113 
                 external ring 
               
               
                 114 
                 recess/socket 
               
               
                 115 
                 recess/socket 
               
               
                 116 
                 well cleaning tool 
               
               
                 117 
                 split housing 
               
               
                 118 
                 cleaning member 
               
               
                 119 
                 external centralizer ring 
               
               
                 120 
                 spline 
               
               
                 121 
                 well cleaning tool 
               
               
                 122 
                 external ring 
               
               
                 123 
                 split housing 
               
               
                 124 
                 cleaning member 
               
               
                 125 
                 snap ring 
               
               
                 126 
                 locking ring/lock wire 
               
               
                 130 
                 well cleaning tool 
               
               
                 131 
                 dovetailed and crimped style brush insert 
               
               
                 132 
                 bullet style brush insert 
               
               
                 133 
                 stuffed style brush insert 
               
               
                 134 
                 split housing 
               
               
                 135 
                 external centralizer ring 
               
               
                 140 
                 well cleaning tool 
               
               
                 141 
                 split housing 
               
               
                 142 
                 cleaning member 
               
               
                 143 
                 external ring 
               
               
                 145 
                 well cleaning tool 
               
               
                 146 
                 split housing 
               
               
                 147 
                 half 
               
               
                 148 
                 half 
               
               
                 149 
                 hinge 
               
               
                 150 
                 cleaning member 
               
               
                 151 
                 external ring 
               
               
                 155 
                 well cleaning tool 
               
               
                 156 
                 tool mandrel 
               
               
                 157 
                 split housing 
               
               
                 158 
                 cleaning member 
               
               
                 159 
                 external ring 
               
               
                   
               
             
          
         
       
     
         [0132]    The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.