Well Casing Thread Protector

1. Field Of The Invention

The apparatus of the present invention relates to oil well tubing, for example, drilling pipe or production casing. More particularly, the present invention relates to an apparatus for engaging the external threads of well casing so as to protect the threads from contact with obstacles while the pipe is being handled.

2. General Background

Protection of the threads of oil well tubing, more particularly, drill pipe or production casing, is a serious and recurring problem in the industry. For purposes of this application, reference to "casing" will encompass any length of tubing used in the drilling or production of oil or gas wells. Casing must be connectedly engaged end to end by threaded connections which must be very secure and be able to protect against leakage of oil or gas under extremely high pressures. Therefore, casing threads are machined to very precise tolerances. However, because the 30 to 60 foot lengths of casing must be handled by machine and moved from racks to be connected to other lengths of casing, it is very difficult to avoid the threaded pin end of the pipe from striking against foreign objects, and the damage to the threads occurring. Of course the slightest deformation of the threads could result in thread malfunctioning.

There have been several patents issued in the art on thread protectors, which patents are addressed in the accompanying prior art statement provided herewith. In addition, one of the co-inventors of the present application has file applications on earlier embodiments, which bear Ser. Nos. 572,266, filed on Aug. 27, 1990, now abandoned, and U.S. application Ser. No. 827,402, filed Jan. 29, 1992, presently pending, both applications incorporated by reference herein. In this application, a co-inventor, Terry Hill, has developed improvements to the current pending application, which improvements greatly simplify and improve the operation of the earlier embodiments.

The present invention solves the problems in the art, and provides improvements over earlier embodiments of the invention, in a simple and straightforward manner. What is provided is a casing thread protector which includes a body member molded of flexible material with resilient and memory characteristics, such as urethane or some other similar material, having a central opening into which a pin end of a length of casing will fit, the body member molded in a slightly open position by having a continuous slot formed in its side wall, to accommodate the casing. A strap is set within a channel formed around the annular wall of the body member, the strap having a locking member at its first opposing end, and an adjustment screw, so that the strap can be adjusted to various locking tightness. Upon sliding the pin end of the casing in the central opening, the locking member is moved to the closed position, tightening the body member around the pin end, so that the threads are completely encircled by the body member. Further, there is provided a recess wherein the locking member is resting, to provide alignment of the body member around the pipe member.

Therefore, it is principal object of the present invention to provide a flexible, resilient protector constructed preferably of urethane, for pipe threads which can easily be secured around and removed from the end of the pipe;

It is a further principal object of the present invention to provide a pipe thread protector which would have a high degree of memory/resilency, formed to be open sufficiently to easily place around the pin end of a casing member, and locked in place with a removable strap and locking member, so that upon unlocking the protector, the protector returns to its normal open position;

It is a further object of the present invention to provide an improved thread protector which provides a molded body member and a removable locking member, so that the locking member can easily be interchanged if damaged;

It is a further object of the present invention to provide a thread protector that can be molded in various sizes, and which provides a locking member which can be easily engaged and disengaged to secure the protector around the length of casing; and

It is a further object of the present invention to provide an improved casing thread protector which, whether in the locked or unlocked position, provides protection of the locking mechanism within the recessed channel formed in the body member.

For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals, and wherein:

FIG. 1 illustrates an overall perspective view of the preferred embodiment of the apparatus of the present invention;

FIG. 2 illustrates a view of the apparatus secured to a length of drill pipe or casing;

FIG. 3 illustrates an overall perspective view of the preferred embodiment of the apparatus secured to the end of a length of pipe or casing;

FIGS. 4 and 5 illustrate side representational views of the apparatus apart from and surrounding a length of pipe, respectively;

FIGS. 6 and 7 illustrate the locking mechanism of the apparatus in the open and closed positions respectively;

FIG. 8 illustrates the adjustment mechanism of the apparatus of the present invention; and

FIG. 9 illustrates is cross-section a length of pipe secured within the apparatus.

FIGS. 1 through 9 illustrate the preferred embodiment of the present invention by the numeral 10. As illustrated more particularly in FIGS. 1 apparatus, or pipe thread protector 10 comprises generally a molded body portion 12, which would be molded in one piece from a hard, resilient neoprene rubber or the like material, so that the member will take contact with foreign objects, and protect the casing end when in place. The body member 12 is formed as a circular member, having a central opening 14 therethrough, through which the casing end 15 would be slidably positioned. On the interior of the central opening 14 there is formed a circular shoulder 16 (See FIG. 9) defining a stop member which the end 17 of the casing 18 would abut up against when positioned properly within opening 14. In order to enlarge the opening 14 while casing 18 is being engaged therein, there is a slot 20 formed through the body member to provide a means to allow that the opening 14 in body member 12 be slightly larger than the diameter of a casing member 18 for facilitating engagement of member 12 therein. Other features of the body member 12 itself includes a beveled edge 22, which is positioned so that, as seen in FIG. 2, when a length of casing is moved via dragging along the ground, and body member is locked around the end 17 of casing 18, that the beveled edge 22 provides the primary surface contact with the ground 23. Further, body member 12 includes a continuous channel 25 in its outer wall 27 through which the means to lock member 12 around the end 17 of casing 18, the structure and function of which will be discussed next.

Turning now to a discussion of the locking means 30 of body member 12, reference is made to FIGS. 1 through 7. The improved locking means 30 includes a simplified embodiment over the embodiment disclosed in the earlier applications. In this improved embodiment, locking means 30 comprises a flexible, fabric belt member 32, constructed of a high tensile-strength fabric, the width of belt 32 being slightly narrower than channel 15, so that strap 32 fits well into channel 25 as illustrated. Structurally, strap 32 is two strap members 34, 36, joined at a first end via an adjustment screw means 38. As seen in FIG. 8), this means comprises a first and second attachment brackets 39, 41 to each of which the ends of strap members 34, 36 attach. Each bracket 39, 41 are secured together via adjustment screw 43, as illustrated, so tightening or loosening screw 43 would slightly adjust the length of strap 32, the reason to be discussed further. The second adjoining ends 40,42 of straps 34,36 define the means by which strap 32 is positioned between engaged and disengaged around body member 12.

Turning now to FIGS. 6 and 7, this means comprises a locking mechanism 50, of the type generally known for locking opposing ends of straps on boots or the like. The mechanism 50 would provide a first bracket 51 to which strap 36 is attached, and a second bracket 53, to which strap 34 is attached. There would be a handle member 52 connecting the two brackets 51, 53, so that rotation of handle member in the direction of arrow 55, as seen in FIG. 7, move the ends of straps 34, 36 into locked positions around body 12, and when rotated in the direction of arrow 57, in FIG. 6, loosens the straps 34, 36 into the unlock position. When the handle 52 is locked as seen in FIGS. 3 and 6, the tension of the straps tightening around body member 12 closes slot 20 formed in the body 12 from its normally open position as seen in FIGS. 1 and 4, to the closed position around casing end 15 as seen in FIGS. 3 and 5, and the end of the casing 18 is secured within circular opening 14. When closed, the handle member 52 is secured in the down position as seen in FIG. 3, so that the handle member 52 is fully positioned within channel 25 and below the side walls 24 of channel 25. Therefore, should the apparatus strike the ground, no part of the locking mechanism 50, including handle 52, would make contact with a foreign object, which may cause inadvertent opening of the body member 12. Likewise, when the handle member is moved to the open position, as seen in FIGS. 1 and 4, the body member 12 returns to its naturally slightly open position as seen in FIG. 4, so that the slot 20 is reopened. This causes the straps 34, 36 to tighten around the body member 12, and in doing so, place sufficient tension on handle 52 to lay it down in the open position in channel 25, as seen in FIG. 1. In the closed position, the locking mechanism is positioned within channel 25 and would not make contact with foreign objects if inadvertently dropped.

As illustrated, channel 25 further provides a recessed area 61, which is of a formation to accommodate the metal brackets 51, 53, to which handle member 52 is attached, as illustrated in FIG. 1. This recessed area 61 allows that the locking mechanism 50, and likewise straps 34, 36, be positioned directly in alignment within channel 25, and therefore, the abutting edges of slot 20 meet squarely when the buckle member 52 closes strap 34, 36 around body member 12. Likewise the channel 25 is provided with a second recessed area 63 where the attachment brackets 39, 41 are positioned, the width of the recessed area 63, as with recessed area 61, being machined so that the brackets 39, 41 are positioned precisely with area 63, and brackets 51, 53 are positioned precisely within recessed area 61. Therefore, when the straps are being locked into place the position of the locking brackets and adjustment brackets within slots 61, 63 are such as that the locking means does not rotate freely around the wall of the member 12, and the straps are stationary despite the force of the locking mechanism which would tend to move the straps within the channel 25.

In summary, FIGS. 4 and 5 illustrate representation views of the apparatus accommodating a length of casing 18. As illustrated in FIG. 4, the apparatus includes slot 20 along its width, so that it is molded normally in the slightly open position to easily accommodate the end of the casing, as seen set in place against shoulder 16 in FIG. 9. When the end 15 is engaged within opening 14 of apparatus 10, the locking mechanism 50 is locked into the position as seen in FIG. 3, and the slot 20, which was slightly open, is pulled closed and the body of apparatus 10 engages securely around the threaded end 15 of casing 18. When the apparatus is unlocked as seen in FIG. 8, body 12 returns to its natural open position as seen in FIG. 1, and the casing can easily be retrieved therefrom. As was stated earlier, because the body member is normally open, the locking straps 34, 36 around its exterior are always pulled taut around the body, and therefore, even in the open position, locking mechanism 50 is engaged in such a manner that no part of the locking mechanism extends beyond the height of the walls 24 of channel 25 formed in the wall of body 12 where locking straps 34, 36 are set in place.

The use of the simplified and improved strap and buckle arrangement as described provides a simplified closure and opening mechanism for the apparatus over both the prior art and the earlier embodiments as described in the pending application. There is no longer a needed to fold the strap upon itself, weave it thorough the closure buckle. A simple forward and backward motion of the handle locks and unlocks the body member around the casing. That is, when the handle means is in the locked position, a flip of the handle will have it move past the centerline of travel. The memory feature of the urethane will cause the body to return to the open position, and, in effect, the handle will travel to the unlocked position, without further urging. This will provide that the handle is housed within channel 25 at all times during use of the apparatus. Furthermore, the closure strap is totally disconnected from the body member at all times. If the strap, for some reason, malfunctions, it may easily removed, and another strap set in place.

pipe thread protector 10

body portion 12

central opening 14

pipe end 15

circular shoulder 16

casing 18

slot 20

beveled edge 22

ground 23

sidewalls 24

channel 25

outer wall 27

locking means 30

belt member 32

strap members 34, 36

screw means 38

adjustment brackets 39, 41

screw 43

locking mechanism 50

handle member 52

first bracket 51

second bracket 53

arrow 55

arrow 57

recessed area 61

recessed area 63

Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.