US 3247914 A
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Description (OCR text may contain errors)
2 Sheets-Sheet 1 Filed Oct. 2 1962 INVENTOR L/OH/V 52 196K April 26, 1966 J. SLACK 3,247,914
COMPLETION OF WELLS Filed Oct. 2, 1962 2 Sheets-Sheet 2 ATTORNEYS United States Patent 3,247,914 COMPLETIQN 0F WELLS John dlaclr, Houston, Tex., assignor to Gray Tool Company, Houston, Tom, a corporation of Texas Filed @ct. 2, 1962, Ser. No. 227,779
9 (Claims. (Cl. l75'7) This invention has reference to well completion, and contemplates a new and improved method and structure for protecting well casing heads, includes tubing heads and the first joint connection between the head and the casing when drilling or other similar operations are to take place.
Once a well casing head is set on the casing pipe, the well is prepared for subsequent drilling through control equipment carried above the casing head. In such instances, the upper end of the casing is commonly threaded to the lower interior end of the passage through the casing head. When the drilling equipment is lowered through the casing head, damage may be done to the casing head passage and particularly the seating bowl or surface which subsequently supports and seals with a hanger. In order to minimize'this damage and insure that the drilling equipment is concentric within the casing head so that the drill bit, for example, does not score the bowl, various protectors have been devised which normally extend upwardly from the bowl and which must usually be retrieved by special equipment connected to their upper ends. Such prior art protectors for easing head bowls and the like, while intended to serve the purposes mentioned, do not afford any worthwhile protection for the first joint connection between the casing head and the upper end of the casing. Moreover, the protectors in the prior art are oftentimes of complex and expensive construction and difi'icult to retrieve in the field after the drilling is completed and removal is desired.
Moreover, due to the construction and short length of prior art protectors of this character, difiiculty has been encountered in passing them through the control equipment above the casing head; and, jamming, occasioned by longitudinal tilting of the protector, has resulted. The protector of the present invention is slipped upwardly over the drill collars just before the drilling bit is attached, and as hereinafter described, it may be removed by the simple operation of elevating the drilling bit through the casing head and the control equipment.
According to the present invention, there is provided a new and improved method for protecting both the casing head bowl and the first joint below, there being provided a protector of substantial length which has a tapered exterior upper surface which seats in the bowl to protect the same. This protector is of a substantial length, sufficient to extend below this first joint where the most severe wear usually occurs. In order to handle the protector, the same is constructed and arranged to be rested or supported by the lowermost end of the drilling equipment, i.e. the drill bit; and, when the drilling string is lowered through the casing head, the protector is carried with the equipment on the drill bit until it reaches the casing head bowl. Downward movement of the protector is then stopped by the casing head bowl and the drilling equipment is moved downwardly for drilling purposes. When so positioned for support on the casing head bowl, the protector extends a substantial length below this first joint to thereby absorb the wear from the drill string while tripping and drilling; and, due to its long length, the protector has an enhanced wear capacity. When drilling operations are completed and the drilling equipment is to be raised, the protector is lifted out of the bowl by the upwardly-moving drill bit so that separate removal equipment is effectively obviated and the first casing joint as well as the casing head bowl have been protected during this drilling operation.
3,2473% Patented Apr. 26, 1966 Also provided by this invention is a casing head protector of newand improved construction which is operative in cooperation with a casing head assembly and associated drilling equipment to protect the well assembly in an efiicient manner.
These and still further objects, advantages, and novel features of the present invention will become evident in the specification and claims when taken in connection with the accompanying drawings.
In the drawings:
FIGURE 1 is an elevation section view of the casing head with the protector in place during drilling operations; and,
FIGURES 2 through 4 are elevation section views of the sequence of assembling the protector for support to the casing head to protect the casing bowl and the first joint therebelow.
In these figures the control equipment is omitted, but it will be understood that suitable full opening blowout preventors and master drilling valves may be mounted if desired, the protector being of a size to pass through this equipment, while permitting the control equipment to be opened and closed as necessary, to maintain mechanical control of the well. It will be understood that the invention may be used in association with other equipment and practices for drilling and completing wells, for instance, as disclosed and referred to in Watts and Hill Patent 2,766,829.
Referring first to FIGURE 1, there is shown a casing head 10 having a longitudinal passage 12 therethrough. The casing head is of conventional construction, including the side outlets l4 and 16 and an upwardly tapered bowl 18 which is adapted to support casing hangers and a casing string at a subsequent stage of completing the well. The casing 10 has an enlarged, interiorly-threaded portion Ztl at the lower end of the passage 12, this threaded portion Ztl receiving the upper threaded end of a casing pipe 22 which has already been supported in the well and cemented in place in a conventional manner.
There is provided a protector 24 of generally cylindrical construction which is operative to protect both the casing head bowl l8 and the first joint defined by the threaded engagement of the casing pipe 22 with the lower portion 20 of the casing head, as will now be explained. The protector 24 has an enlarged exterior portion 26 at its upper end which is of a diameter D only slightly less than the interior diameter of the casing head passage 22 at this region. This enlarged portion 26 merges at its lower end with a downwardly and inwardly inclined tapered portion 28 which corresponds to the configuration of the tapered casing bowl 18 so that the protector 14 can move no lower than the tapered bowl 1% and is adapted to be temporarily supported thereby. Next, the protector has a lower portion 3t) of substantial length, extending well below the first joint described above and which is of an outside diameter D less than the inside diameter of the casing pipe 22.
The protector 24 has an interior diameter D which will pass all the parts on the drill string except the drill bit at the lower end, to be explained. Suitable openings 32 diametrically opposed, are formed in the upper portion 26 of the protector 24, extending between the interior and the exterior of the protector 24. These openings 32 are upwardly inclined to a slight degree and may be engaged by an appropriate tool to remove the protector other than with the bit in case this should be necessary. Also, the protector 24, when positioned as shown in FIGURE 1, terminates at its upper extent slightly below the side outlets 14 and 16 so that drilling mud may be circulated during drilling. The bottom end 34 of the protector 24 is smoothly curved so as to rest on the upper end of the drill bit in an eflicient manner as when the mating upper surally inwardly of this exterior diameter.
face of the drill bit is irregularly curved. Suitable full opening control equipment 36 is flanged 'to the upper end of the casing head as is the usual practice during such drilling operations.
Referring now to FIGURES 2 through 4, the sequence of handling the protector 24 will be discussed. In FIG- URE 2, the protector 24 is positioned immediately above the casing head and is supported by a drill bit 38 at the lower end of a drill string 48 so that the protector 24 is in generally concentric relationship with the drilling string 40 as this assembly is lowered into the casing head It A rotary table and the related equipment (not shown) is positioned above the casing head, as is conventional practice in the art.
FIGURE 3 shows the drill bit 38 carrying the protector 24 within the passage 12 of the casing head It) slightly above the bowl 18.
In FIGURE 4, the protector 2-4 with its tapered portion 28, is seated on the bowl 18 of the casing head 10 as the drilling assembly continues downwardly within the well for drilling operations. When so positioned, it is evident that the tripping and drilling operation will not cause adverse damage either to the bowl 18 or the first joint due to the impact of the drilling string 40 at this region.
Moreover, as the assembly is initially placed into the casing head, the diameter D relative to the exterior diameter of the drill bit 38 is such that the diameter D is slightly in excess of the drill bit 38 so that the drill bit is spaced radi- This relationship minimizes'the tendency of the drill bit 38 to strike the interior surfaces of the passage 12 and the casing pipe 22. Also, by virtue of the snug but sliding fit between the upper portion 26 of the protector and the adjacent passage 12, the tendency of the protector 24 to tilt in a longitudinal direction is effectively obviated.
Subsequently, when the drilling has been completed and the drilling string 46 and its drill bit 38 are raised to the surface of the ground, the upper end of the drill bit 38 will again engage the bottom end 34 of the protector 24 and carry the protector 24 upwardly and out of the casing head 10 without any other retrieval equipment being necessary.
It will be observed that the protector is of such length that it will not cock nor jam when it is being elevated through the control equipment, and the same is true when the protector is being lowered through the control equipment.
While we have shown a casing head having a tapered bowl to receive a tapered surface on the protector, it will be understood that the term bowl would include any other engaging surface on a casing or tubing head to receive a hanger or other supporting means.
From the foregoing descritpion of the various embodi ments of this invention, it is evident that the objects of this invention, together with many practical advantages are successfully achieved. While preferred embodiments of my invention have been described, numerous further modifications may be made without departing from the scope of this invention. For instances, the protector could be carried on and above any other tool which is inserted into a well for manipulation therein under circumstances where a protector would be useful.
Therefore, it is to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted in an illustrative and not in a limiting sense.
What is claimed is:
1. Method of well composition comprising the steps of:
(A) mounting a casing head to the upper end of a casing to define thereby a first joint, the casing head having a bowl for receiving a hanger assembly;
(B) aligning a drilling string with a drill bit or the like at its lower end above the casing head;
(C) positioning a protector about the drilling string with its lower end supported by the drill bit, the protector having an upper portion thereof arranged for engagement with the casing head bowl and a lower portion arranged to'extend downwardly through said casing head; (D) lowering said drilling equipment through said casing head to thereby carry said protector downwardly on said drill bit for support by said casing bowl, but allowing further downward movement of said drilling string for drilling or similar operations;
(E) and then performing the drilling or similar operations while said protector thereby prevents damage to said casing head bowl.
2. Method defined in claim 1 including the step of raising the drill bit out of the Well, the drill bit carrying the protector upwardly from its position within the casing head.
3. Method of well completion comprising the steps of:
(A) mounting a casing head to the upper end of a casing to define thereby a first joint the casing head having a bowl for receiving a hanger assembly;
(B) positioning a protector about the drilling string,
the protector having an upper portion thereof arranged for engagement with the casing head bowl and a lower portion arranged to extend downwardly through said casing head;
(C) passing a drilling string with a drill bit at its lower end through said casing head, the drilling string carrying the protector;
(D) engaging the protector with the casing head as the drill bit is moved through the casing head so that the protector prevents damage to the casing head bowl and the first joint;
(E) and continuing the downward movement of the drill bit below the protector for drilling operations.
4. Method defined in claim 3 including the step of lifting the protector out of the casing head by raising the drilling string after completion of the drilling operations.
5. For use in well completion equipment including a casing head having support means and a casing secured to the lower end of the casing head to define thereby a first joint: a protector of generally tubular construction, said protector having an upper portion of enlarged outer diameter operative to be supported by said casing head on said support means, and a lower portion having an exterior diameter sufiicient to pass through said casing head below said support means, the longitudinal distance between the upper and lower extent of said lower portion being greater than the longitudinal distance between said joint and the lower extent of said support means, the interior diameter of said protector being of a size to pass a drilling string except for a drill bit, whereby said protector may be lowered via a drill bit into a supported position relative to said casing head to protect said support means and said first joint during drilling operations.
6. In combination: a casing head having a seat for receiving a hanger assembly and having side outlets; said head having means at its lower end to connect with and suspend a well casing; a generally tubular protector operative for support on a drilling bit or the like in surrounding relationship to a drill string, said protector having an upper portion of enlarged exterior diameter operative to be supported on the seat of said casing head; and a lower portion of an exterior diameter sufiicient to pass through said casing head below said seat, said lower portion being of a length suflicient to extend to said connecting means, whereby said protector may be lowered upon a drilling bit or the like into a supported position relative to said casing head to protect said seat and said connecting means.
7. The combination defined in claim 6 wherein said protector is of such substantial length and upper exterior diameter to prevent axial tilting of said protector when it is lowered through control equipment on said casing head said upper exterior diameter being of a size to provide a snug sliding fit between the protector exterior and said control equipment.
8. The combination defined in claim 7 wherein said casing head seat is of tapered configuration, and including a tapered portion about the exterior of said protector between said upper and lower portions operative for generally coextensive engagement with said seat.
9. The combination defined in claim 7 wherein the upper portion of said protector is. constructed and arranged to prevent obstruction of said side outlets when said protector is supported by said casing head bowl.
References Cited by the Examiner UNITED STATES PATENTS Hansen.
Bauer et a1 16688 X Meredith et a1 16646 X Gibson et a1 175--7 Haeber et al 16675 CHARLES E. OCONNELL, Primary Examiner.