US 3901331 A
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[ Aug. 26, 1975 Djurovie 1 SUPPORT CASING FOR A BORING HEAD  Inventor: Branko Djurovic, Clichy, France  Assignee: Societe Anonyme of Compagnie Francaise des Petroles, Paris, France  Filed: Dec. 3, 1973  Appl. No: 420,838
 Foreign Application Priority Data Dec. 6, 1972 France 1. 72143343  U.S. Cl. 175/171; 175/101; 175/103; 175/173; 175/258; 175/261  Int. Cl. E21B 43/01; E218 7/12  Field of Search 175/92, 101, 103, 107, l75/l7l, 173, 257, 258 260, 26l, 62,171
 References Cited UNITED STATES PATENTS 1 295 969 3/1919 Carmichael .1 175/260 2239996 4/1941 Chappell 2. 175/261 3.199.613 8/1965 Malott ct a]. 175/257 X 3,216 512 11/1965 0111616 175/171 x 3.262508 7/1966 PriCC 175 171 x 3.491342 1/1970 0611166111 et 111W. 175/171 x 3519.071 7/1970 Word 1. 175/171 x 3.552.508 1/1971 Brown 175/258 3552.509 1/1971 Brown 1 v A t w 175/2511 3,703,212 11/1972 Abrahams.... 175/171 x 3,7321143 5/1973 .lOOSSC 4. 175/101 x Primary Examiner-David H. Brown Attorney, Agem, 0r F1'rmSughrue. Rothwell, Mion, Zinn and Macpeak 13 Claims, 15 Drawing Figures PATENTED AUS 2 6 i975 PATENTEU 2 1975 SILET 5 BF 5 gig g g 5 22a 22 v g ii um fi m "Ea. .i 22
SUPPORT CASING FOR A BORING HEAD The invention relates to a support casing apparatus for a drilling head applicable to all earth boring work and in particular to under-water petroleum drilling.
The need to protect bore holes and in particular petroleum drill holes leads to the use of a casing placed in position after drilling a pre-hole. For this purpose. the first drill hole is enlarged by means of a suitable tool and then after removal of this tool the casing is lowered into the hole. All these operations are lengthy and costly. They are still more so in the case of an underwater petroleum drill hole. Moreover, when drilling is carried out in soft ground, it is not unusual for cave-ins to occur between the moment of drilling and the location of the casing, thus necessitating further work.
According to the present invention there is provided a support casing apparatus for a drilling head comprising (1) a casing wherein the head is connected to the casing by a bearing connecting means permitting free rotation of the head about its axis, (2) first means for coupling the head to a lower portion of a pipe string carrying a drilling tool to drive the head, and (3) a second coupling means located at the upper portion of the casing for rigidly attaching it to a pipe string.
It is therefore sufficient for placing the casing in position in a single operation to select a drilling head and a drilling tool, a bit for example. suitable for the soils to be encountered. The combination of the bit, the head, and the casing fixed on its orientation relative to the soil forms in itself both a drilling tool of sufficient diameter for the introduction of the casing and a pipe for protection of the drill hole in which muds and drilled soil may subsequently be raised. Thus all the intermediate operations of lowering and lifting the tool, enlarging the first drill hole, and placing the casing in position are avoided.
To facilitate the actual drilling in the case of unforeseen change of the tool without having to raise the easing fitted with its drilling head, the coupling means of the head relative to the drilling tool may be arranged so that the head is set back relative to the tool and means may be provided on the upper part of the casing to rigidly connect the latter to guide means used for recovery of the original drilling tool after the casing has been placed in position and to guiding means for coupling the upper end of the casing to the pipe string.
The present invention will be more fully understood from the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, wherein:
FIGS. la and lb are diagrammatic views. partially in axial section, of an embodiment of easing apparatus according to the invention and including means for coupling to pipe string and to a bit;
FIG. 2 is an axial section of apparatus for control of means for coupling to the pipe string;
FIG. 3 is a section along the line Ill-III of FIG. In;
FIG. 4 is a section along the line IV-IV of FIG. In;
FIG. 5 is a section along the line V-V of FIG. Ia,-
FIG. 6 is a sectional view of a detail of bearing means connecting the drilling head to the casing;
FIG. 7 is a view from below the head in the drilling position;
FIGS. 8 8s 9 are sections along the lines VIII-VIII and IXIX of FIG. 7;
FIG. 10 is a section along the line X-X of FIG. lb;
FIG. 11 is a perspective view ofa cutaway portion of a modification of the head;
FIG. 12 is a diagrammatic view of the outer portion of a bit co-operating with the head of FIG. 11;
FIG. 13 is a general view of the casing separated from the drilling tool, and
FIG. I4 is a diagrammatic representation of the well of a drilling barge.
In FIGS. la and lb, meeting along cut line I, it will be seen that casing assembly 2 comprises a pipe or casing 3 provided at its lower portion with a head 4 and a bearing means 5, a detail view of which is given in FIG. 6. At its upper portion, casing 3 is shaped to receive an assembly 6 including a first coupling means having latches 8 and a plate 27 known as a base plate and supporting a guide assembly 7 acting as guide means for the reintroduction of bit 28-for example after tool changing to recommence drilling.
The coupling means of assembly 6 may be a conventional hydraulically controlled connector. To clarify the drawing, the latches 8 of the coupling means have been shown symbolically. As the conventional mechanism may be of any known type, it will not be further described. Only control pipe 37, which is used for unlocking the coupling means, has therefore been shown in the drawing. In the absence of pressure in control pipe 37, latches 8 extend into one of a plurality of circular grooves 3a in the upper portion of easing 3 rigidly attaching assembly 6 to the casing 3.
The upper end of assembly 6 is welded along the whole of its periphery to a castillated member 9, shown in plan in FIG. 3 and from below in FIG. 4. The weld line has been shown at 40 and 41. Member 9 has a central aperture which is castellated. the castellations or splines engaging in three longitudinal grooves 420 in a threaded pipe 42. Threaded pipe 42 is attached to pipe string 45 by upper joint 38 and lower joint 26, shown in FIG. 2, so that rotation of assembly 6 locked on casing 3 relative to pipe string 45 is prevented.
The position of castellated member 9 on threaded pipe 42 is determined by a member 10, FIG. 5. having a central threaded aperture. In order to rigidly attach pipe string 45 to assembly 6, it is sufficient to screw member 10 onto threaded pipe 42 to the required height, i.e. to a height permitting latches 8 to penetrate one of the circular grooves 3a in the upper portion of easing 3 when castellated member 9 rests on member 10, and then to fix castellated member 9 on member 10.
In order to facilitate screwing of member 10 onto threaded pipe 42, a certain number of threaded holes are provided in the peripheral surface of the member 10 permitting insertion of a bar having an end threaded with the same thread as these holes. After member 10 has been brought to the selected level and the above bars have been removed castellated member 9 is attached to member 10. For this purpose. castellated member 9 is provided with three openings 9b allowing passage of the shanks of bolts 43 therethrough and into threaded holes 10b of member I0, openings 9b being of sufficient angular dimensions for at least one threaded hole 10b to be exposed to receive a bolt 43 whatever the angular position of member I0 relative to castellated member 9. The heads of the bolts 43 bear on the bases of grooves 9c bordering the openings 9b. A seal between the interior of easing 3 below castillated member 9 and the external environment is provided by annular elastic seals 44 in two circular grooves I01." in member I mating with two corresponding circular grooves M in castellatcd member 9.
The upper portion of threaded pipe 42 is connected to rod string 45 by lower joint 26, FIG. 2, which has an internal sleeve 36 normally retained by shear screws or pins 46. The internal sleeve 36 blocks a passage 26a extending control pipe 37, seals 53 ensuring the fluid tightness of the sleeve. The upper joint 38 rigidly attaches the lower joint 26 to rod string 45.
The upper portion 360 of internal sleeve 36 acts as a seat for a closure member 39 when the latter descends through rod string 45 to cause the automatic unlocking of assembly 6. When a frusto-conical portion 39a of closure member 39 rests on seat 360. the pressure inside rod string 45 increases until shear pins 46 are broken and internal sleeve 36 is driven until it comes to rest on seat 26b provided in lower joint 26. When internal sleeve 36 rests on seat 26b, internal sleeve 36 frees the passage 26:: and thus causes the pressurisation of control pipe 37 causing unlocking of latches 8 of assembly 6. This action is sufficient to disconnect assembly 6 from the upper portion of easing 3.
The lower portion of threaded pipe 42 is connected to the drilling attachment. figures Ia and lb, by a pipe string comprising a stem 11 supporting a turbine 12, the shaft 13 of which drives bit 28 through a diminisher 14.
In the embodiment illustrated, the bit 28 includes three retractable arms 15 which are also visible in FIG. I0. The double-ended arrows in FIG. I0 are intended to illustrate the retractability of the retractable arms IS. The retractable arms I are driven by the bit 28 as it rotates, permitting angular coupling of the bit 28 to the head 4 by any known means. The head 4 may be of any type and have soil attacking zones 4a, FIGS. 7 to 9, of any suitable form, for example as shown in FIGS. 8 and 9. As shown in FIG. 10, the means for coupling bit 28 to head 4 may consist of recesses 4b provided in the head 4 and of the retractable arms of bit 28 which enter these recesses.
The head is preferably mounted as shown in FIG. 6, in which the lower end of easing 3 comprises a lower housing for insertion of bearing means such as ballbearings 16 bearing directly on the upper portion of head 4 and a lateral housing for bearing means such as ball-bearings 17 retained by a ring or annular member I8. Ring I8, rigidly attached to head 4 by screws 19, ensures with seals 20 and 21. which may for example be lip seals. the fluid tightness of bearing means 5.
In the modified head 33, a portion of which is illustrated in FIG. ll. instead of the straight-edged recesses 4b of head 4, FIGS. 7 to I0, recesses 29 are provided. one of the edges 30 of which is extended by a ramp 3i and the other edge 32 of which extends up to the ramp 3i of the preceding recess 29.
Because of the relatively large number of recesses and the arrangement of the ramps. the structure of head 33 provides the advantage of being able to receive shoulders 34 of bit 35 shown in FIG. 12 and easily guiding them to the bases of recesses 29. A quick. strong. and efficient joint is thus formed, since it is sufficient for shoulders 34 to impinge either laterally on an edge 32 or vertically on a ramp 31 in order for the shoulder 34 to be guided to the base of recess 29.
When it is required to drill in an under-water environment with the above described apparatus. easing 3 is provided with its bearing means 5 and head 4 (or 33) and is lowered by means of derrick 47, FIG. 14, and rotary table 49 mounted on the upper deck 48 of the drilling barge 22. The rotary table 49 is used to form the overall casing 3 progressively by adding additional sections of easing as each section is sunk into the soil 25. The length of easing 3 may vary depending on the nature of the soil 25 in which drilling is to be carried out. Base plate 27, on which guide assembly 7 rests, may be fitted on the retractable floor plate 51 of the lower deck 50 inside wall 220. Attachment of base plate 27 to casing 3 is effected by simple application of profile 27a of plate 27 to profile 3b of casiing 3, followed by clamping, seals 52 being provided between these elements. For this purpose. the casing 3 is lowered by means of a handling pipe until profile 3b of the casing, FIG. la, reaches the level of profile 27a of base plate 27. The casing 3 is then rotated until it reaches the position shown in FIG. la, in which the base plate 27 is locked on profile 3b of the casing, and the handling pipe is raised. It will be noted that in addition to guide assembly 7, plate 27 bears arms 23, FIG. I3, at the ends of which sonar reflectors 24 are provided for facilitating access to the well head-at a tool change for example.
When casing 3, still retained by the derrick 47, has been thus equipped, the drilling attachment comprising the stem 11, the turbine 12, the shaft 13, the diminisher I4, and the bit 28 (or 35) is lowered into casing 3. Thus the bit 28 (or 35) is attached to diminisher l4 driven by turbine 12 connted to stem 11, and the drilling attachment is lowered progressively into casing 3 until the bit 28 (or 35) reaches head 4 (or 33) and effects bit head interlocking as already described, interlocking being carried out either by engaging retractable arms 15 in recesses 4b, FIG. 10, or bringing shoulders 34 into contact with the bases of recesses 29, FIG. 11. As described above, threaded pipe 42 is then placed in position. member 10 is then screwed onto the rod to act as an attachment means for castellated member 9 rigidly attached to assembly 6, which in turn is locked onto the upper portion of easing 3 after mounting of lower joint 26 and upper joint 38. It is clear that the length of the drilling attachment is such that when hit 28 (or 35) is engaged with head 4 (or 33) and member 10 has been screwed to the necessary height on threaded pipe 42, latches 8 fit into circular grooves 3a so that casing 3, the drilling attachment, and the pipe string 45 which is subsequently attached) form an assembly which can be lowered after complete opening of retractable floor plate 51 until the bit 28 (or 35) reaches the drilling location.
If the nature of the soils requires it. a plate similar to base plate 27 may optionally be lowered in advance to the actual point of drilling. and this plate may also carry sonar reflectors facilitating the start of the drilling.
When turbine 12 drives the diminisher I4 and therefore hit 28 (or 35 only head 4 (or 33) is rotated pipe string 45 and easing 3 being subjected only to a lowering motion. During this part of the drilling. the mud rises between the casing and the soil.
If for some reason or other the drilling attachment comprising elements 11 I4 and 28 needs to be raised before casing 3 has been completely sunk into the ground. it is sufficient. after having caused the retraction of retractable arms 15, where bit 28 is being used, to introduce closure member 39 into the duct of pipe string 45 to cause breakage of shear pins 46. the drop of internal sleeve 36, and the application of pressure to control pipe 37, causing the withdrawal of latches 8. Where bit 35 is used, the process is obviously analogous. The rod string may then be raised with the drilling attachment and, after possible changing of the tool, the assembly may be lowered after replacement of lower joint 26 and its internal sleeve 36. As the apparatus for guidance by sonar reflectors 24 may be of any conventional type, it has not been described, and it is evident that, although the preferred embodiment of the invention includes such means, other types of conventional guide means, such as anchor cables, could alternatively be used. When the bit reaches guide assembly 7, it is sufficient to lower the pipe string until the bit and the head interlock for assembly 6 to again be in the locking position on the upper portion of casing 3. Drilling is accomplished jointly by the bit and the head and is continued until the casing has been completely sunk in so that base plate 27 reaches its final operating position. Depending on the bit used, drilling maybe pursued immediately without raising the drilling attachment, or else the tool changed as described above.
It is evident that when drilling is shallow and the nature of the ground lends itself to it, member 10 may be dispensed with, and threaded pipe 42 may be replaced by a simple grooved rod, the castellated member 9 being rigidly attached to the said rod or otherwise. However, in other cases, die embodiment described is particularly effieient, whatever may be the soils en countered and the vibrations due to the rotation of the tool.
What we claim is:
l. A support casing apparatus for a drilling head comprising a casing, wherein the head is connected to the casing by a bearing connecting means permitting free rotation of the head about its axis, first means is provided for coupling the head to a lower portion of a rod string carrying a drilling tool to drive the head, the casing has at its upper portion second coupling means for rigidly attaching it to a pipe string, the second coupling means include a castellated member and in the pipe string includes a pipe with longitudinal grooves in which the castellations of the castellated member are engaged, the rod being attached at its lower portion to a stem supporting a turbine for driving a drilling tool and at its upper portion to a joint of the upper portion of the rod string, the said joint being provided with a sleeve controlled by a valve and with a pipe connected to and for causing unlocking of the second coupling means, such that operation of the sleeve causes release of the pipe string from the casing.
2. Apparatus as claimed in claim 1, wherein the castellated member is rigidly attached to a means for locking the castellated member on the grooved rod.
3. Drilling apparatus comprising:
a. a mobile drilling head having bearing recesses in its inner wall;
b. an immobile casing extending upwardly from said mobile drilling head;
c, a drilling bit;
d. a pipe string rigidly connected to said drilling bit and extending upwardly through said immobile casing e. means for coupling the upper portion of said immobile casing to said pipe string;
f. a plurality of retractable arms mounted on said drilling bit in a position to cooperate with corresponding bearing recesses in said mobile drilling head to rigidly connect said mobile drilling head to said drilling bit.
4. Drilling apparatus as recited in claim 3 comprising a. an annular member rigidly connected to said mobile drilling head and extending for a short distance upwardly therefrom around said casing;
b. a first ball bearing mounted in a first sealing positioned between said casing and said mobile drilling head;
c. a second ball bearing mounted in a second sealing positioned between said casing and said annular member; and
d. means of fluid communication connecting said first and second sealings.
S. Drilling apparatus as recited in claim 3 wherein said casing has at least one recess on the upper outer portion thereof for the attachment of a base plate.
6. Drilling apparatus as recited in claim 3 wherein said means for coupling the upper portion of said immobile casing to said pipe string comprise:
a. an annular assembly surrounding said casing and b. a vertical adjustment means comprising i. a threaded pipe;
ii. means for integrally connecting said threaded pipe to the upper end said pipe string;
iii. a castellated member supported by threaded pipe; and
iv. a threaded member which is threaded on said threaded pipe, attached to said castellated memher, and attached to said annular assembly.
7. Drilling apparatus as recited in claim 6 wherein said threaded pipe has longitudinal grooves to receive the castellations on said castellated member.
8. Drilling apparatus as recited in claim 6 wherein said threaded member is attached to said castellated member by means of bolts.
9. Drilling apparatus comprising:
1. a mobile drilling head having a series of consecutive recesses on the inner surface thereof, each of said consecutive recesses having a first vertical edge, an inclined ramp extending upwardly from the first vertical edge, and a second vertical edge opposing the first vertical edge and extending upwardly to the top of the inclined ramp of the adjacent recess;
2. an immobile casing extending upwardly from said mobile drilling head;
3. a drilling bit having a plurality of shoulders each of which is shaped to fit into one of the recesses in said mobile drilling head to rigidly connect said mobile drilling head to said drilling bit;
4. a pipe string rigidly connected to said drilling bit and extending upwardly through said immobile casing, and
5. means for coupling the upper portion of said immobile casing to said pipe string,
said means for coupling the upper portion of said immobile casing to said pipe string comprise:
a. an annular assembly surrounding said casing and b. a vertical adjustment means comprising i. a threaded pipe; ii. means for integrally connecting said threaded pipe to the upper end of said pipe string;
positioned between said casing and said annular member; and
d. means of fluid communication connecting said first and second sealings.
11. Drilling apparatus as recited in claim 9 wherein said threaded pipe has longitudinal grooves to receive the castellations on said castellated member.
12. Drilling apparatus as recited in claim 9 wherein said threaded member is attached to said castellated member by means of bolts.
13. Drilling apparatus as recited in claim 9 wherein said casing has at least one recess on the upper outer portion thereof for the attachment of a base plate.
DATED INVENTOR(S) I 2 3,901,331 August 26, 1975 Branko Djur ovic It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, Column 2,
Column 3, Column 4,
C olumn 5 Column 6,
[SEAL] line line
Signed and Sealed this sixteenth Day of March 1976 A ttest:
RUTH C. MASON Arresting Officer C. MARSHALL DANN (mnmissr'uner of Parents and Trademarks