US3199613A

US3199613A - Method and apparatus for drilling an underwater well

Info

Publication number: US3199613A
Application number: US226797A
Authority: US
Inventors: Raymond A Malott; Glenn D Johnson
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1962-09-28
Filing date: 1962-09-28
Publication date: 1965-08-10
Anticipated expiration: 1982-08-10

Description

Aug. 10, 1965 METHOD AND R. A. MALOTT ETAL 3,199,613

APPARATUS FOR DRILLING AN UNDERWATER WELL Filed Sept. 28, 1962 4 Sheets-Sheet l FIG. I FIG. 2

INVENTORS:

R. A. MALOTT G. D. JOHNSON THEIR AGENT 1965 R. A. MALOTT ETAL 3,199,613

METHOD AND APPARATUS FOR DRILLING AN UNDERWATER WELL Filed Sept. 28, 1962 4 Sheets-Sheet 2 INVENTORS:

R. A. MA LOTT G. D. JOHNS ON M H-i cwz THEIR AGENT Aug. 10, 1965 MALOTT ETAL 3,199,613

METHOD AND APPARATUS FOR DRILLING AN UNDERWATER WELL Filed Sept. 28, 1962 4 Sheets-Sheet 3 3 r- I I} r :F

-47 37 o O O O 3 Q 0 o O "30 39 I 4-35 Q I 57? 5'65 gfl64 56 6 so 1? 34 I J 53 FIG. 9 5| INVENTORSI T FIG. 7 R A MALO T G. D. JOHNSON THEIR AGENT 1965 R. A. MALOTT ETAL 3,199,613

METHOD AND APPARATUS FOR DRILLING AN UNDERWATER WELL 28, 1962 4 Sheets-Sheet 4 Filed Sept.

T w T 0 m Q I I M H I. MI: M m u 'm G ll F m A D w T R G Q N E V N I Y B H M M 2 Q V 4 2 a Q $QI I 4T A... V VAk A/K B M .10. NA

THEIR AGENT FIG. I2

United States Patent 3,199,d13 P/iETl-lfil) AND APPARATUS FGR DRl-LLING AN UNDERWATER WELL Raymond A. Malott, Fullerton, and Glenn D. Johnson, Downey, Calif., assignors to Shell Gil tlompany, New York, N.Y., a corporation of Delaware Filed Sept. 23, 1952, Ser. No. 226,797 Qlaims. (til. 175-5) This invention relates to underwater drilling of oil and gas wells and pertains more particularly to methods and apparatus for re-establishing contact with an underwater well after changing a bit during drilling operations or :hen installing in the well a conductor, foundation pipe, or other large-diameter well casing.

During recent years, the continued search for oil has resulted in developing methods and apparatus for drilling underwater wells at locations where the water may range from 100 to 1500 feet or more in depth. In these locations it is customary to position the wellhead at a considerable distance below the surface of the water, preferably on the ocean floor, so that it is not a hazard to the navigation of ships in the area. One method of drilling and completing wells underwater in this manner is described in copending patent application, Serial No. 830,538, filed July 30, 1959, and entitled Underwater Well Completion Method.

One of the most important operations in the drilling of an underwater well is that of starting the well and installing the conductor or foundation pipe in th ocean floor. This operation may be carried out in any one of several ways, two of which are described in US. Patent 2,929,610 which issued March 20, 1966 to H. Stratton, and US. 2,891,770 which issued June 23, 1959 to R. P. Bauer et al. In one method a drill bit drills a hole in the ocean floor slightly larger in diameter than the diameter of the well conductor or foundation pipe which is subsequently slipped down along the drill pipe and into the hole during which time drilling fluid is pumped down the drill pipe and up the outside of the foundation pipe. In another method, a hole is flushed in the ocean floor for the well conductor or foundation pipe by pumping fluid down through the conductor, allowing it to jet out the lower end thereof to wash a hole in the ocean floor into which the conductor pipe is progressively lowered. The conductor pipe is then held in the hole until the surrounding earth has had time to settle in around the outside of the pipe and anchored firmly in the hole. In certain locations, the above-described methods of starting to drill a well in the ocean floor and posi' tioning a well conductor or foundation pipe therein are unsatisfactory because of the soil conditions of the ocean floor or the drilling conditions in general. In some areas it is necessary to change a drill bit prior to installing the well conductor or foundation pipe. In employing one of the presently known methods or starting a well in the ocean floor, it is impossible to change a bit at the end of the drill string since contact would be lost with the hole in the ocean floor when the drill string and is bit were withdrawn to the vessel at the surface of the ocean in order to change the bit. Contact between the vessel and the hole in the ocean floor would also be lost in the event that it was necessary to withdraw the drill string from the hole during a severe storm.

It is therefore a primary object of the present invention to provide a method for establishing contact between a vessel floating on the surface of the ocean and a hole or well in the ocean floor.

A further object of the present invention is to provide a method and apparatus for starting the drilling of an underwater well with the drill bit and subsequently chang- 3,19%,613 Fatented Aug. 10, 1965 ing the drill bit to a new one of the same size or one of another size without losing contact between the hole and the ocean floor and the vessel on the surface of the ocean.

Another object of the present invention is to provide apparatus for guiding well drilling equipment or tubular members from a vessel on the surface of the body of water to a well or a well foundation pipe sunk in the ocean floor so that well drilling operations may be continued after the original hole has been drilled or after the foundation pipe has been installed therein.

It is a further object of the present invention to provide a method and apparatus for guiding the lower end of a pipe string suspended from the vessel into contact with an underwater wellhead for work-over operations.

These and other objects of this invent-ion will be understood from the following description taken with reference to the drawing, wherein:

FIGURES 1 through 4 are diagrammatic views taken in longitudinal projection illustrating a floating vessel positioned over a drilling location during the sequential steps of starting a well, withdrawing the drill string back to the vessel, lowering a pipe string from the vessel to a point adjacent the ocean floor, and reestablishing contact between the vessel and the well in the ocean floor by 10- cating the well and inserting at least the lower end of the pipe string in the well.

FlGURE 5 is a diagrammatic view taken in longitudinal cross section illustrating the lowering of an auxiliary drill bit into the lower end of a pipe string or drill string;

FIGURE 6 is a diagrammatic view taken in longitudinal projection illustrating a floating vessel positioned at a drilling location with a pipe string depending from the vessel and establishing contact with an underwater wellhead.

FIGURE 7 is a view taken partially in longitudinal cross section illustrating a television camera observation unit positioned in the lower end of a drill string and extending through an opening in the bit thereof;

FIGURE 3 is a cross sectional view taken along the line 88 of FIGURE 7;

FIGURE 9 is a view taken in partial longitudinal cross section illustrating the lower end of the drill string of FIGURE 7 with the axial opening through the bit being provided with an auxiliary or pilot bit;

FIGURE 10 is a longitudinal view taken partially in cross section of the lower end of a pipe string illustrated as being provided with a valved jet port through the side wall thereof and means for orienting an observation unit in the bore thereof;

FIGURE 11 is a longitudinal view taken partially in cross section of the pipe string of FIGURE 9 with an observation unit positioned therein and latched to a fishing tool; and

FlGURE 12 is a diagrammatic view taken in longitudinal projection of another form of well-locating apparatus.

Referring to FIGURE 1 of the drawing, the drilling vessel, barge or platform 11, of any suitable floating or floatable type, is illustrated as floating on the surface of a body of water 12 while being substantially fixedly positioned over a preselected well location by suitable vessel-positioning means well known to the art, or by being anchored to the ocean floor 13 by

anchor lines

14 and 15 running to anchors (not shown). Equipment of this type may be used when carrying on well-drilling operations or well work-over operations in watervarying from about feet to 1500 feet or more in depth. The drilling vessel 11 is equipped with a suitable derrick 16 containing a fall line system 17 which'includes a suitable hoist 18, traveling block 19, and suitable hook and swivel or other connector means 20 adapted to be connected to the top of a drill pipe 21 during well drilling operations and being adapted to circulate a drilling fluid therethrough in a manner well known to the art. The vessel 11 is also provided with other auxiliary equipment needed during well drilling operations, such for example as a rotary table 22 positioned on the operating deck, a hinged slip and spider assembly, etc. The derrick 16 is positioned over a drilling slot or well 23 which extends vertically through the barge in a conventional manner. When using equipment of the present invention, a slot 23 in the vessel 11 may be either centrally located or extend in from one edge. Alternatively, drilling operations may be carried out over the side of the vessel without the use of a slot. For example, the drilling vessel may be provided with a deck portion which overhangs the hull of the vessel.

In drilling a well in accordance with the method of the present invention while using the apparatus described, a drilling vessel is positioned at a selected offshore location and a drill string including a bit secured to the lower end thereof is lowered from the vessel into contact with the formation beneath the body of water. A hole or well is formed in the formation, as by drilling, while advancing the drill string thereinto. After the hole has been drilled to a desired depth, the drill string is withdrawn from the hole and back to the vessel. A pipe string having an axial opening in the lower end thereof is then made up at the vessel and lowered from the vessel to a position near the formation beneath the body of water. A well-locating device preferably in the form of an observation unit, for example a television camera, is lowered through the pipe string to the lower end thereof so that it is in register with the opening in the lower end. The pipe string, or at least its lower end together with the television camera is moved substantially laterally relative to the formation to locate the top of the hole drilled in the formation so that the lower end of the pipe string can be positioned in register thereabove. Alternatively, if the lower end of the pipe string is close to the hole or well in the formation when it is originally lowered, it may be sufi'icient merely to rotate an element of or the entire camera means at the end of the pipe or the pipe itself in order to find the hole. After locating the hole, at least the lower end of the pipe is positioned in the hole after which the television camera is withdrawn back to the vessel. The pipe string extending between the vessel and the ocean floor is used as a guide string along which a foundation pipe or well casing may be guided into a well. If further drilling is to be continued, a drill bit may be lowered through the pipe string to convert the pipe string to a drill string. In such a case the drill bit would be either an auxilary or a core-type bit which would replace the observation unit in the bottom of the pipe string.

The drill string 21 (FIGURE 1) preferably includes a conventional telescoping joint 24 in its length to compensate for the rise and fall of the vessel 11 relative to the drill string 21. The drill string 21 also includes a drill bit 25 at its lower end which is provided with an axial vertical opening26 (FIGURE 5) therethrough in which a pilot bit 27 or a core bit and core barrel (not shown) may be latched in a suitable manner well known to the art. As shown in FIGURE 9, the auxiliary bit 27 is in the form of a removable rock bit having cutting cones 28 and fluid circulation ports 29. The drilling assembly of FIGURE 9 includes a bit housing or sub 30 threadedly secured to the lower end of the drill string 21. The lower end of the housing or sub 30 is provided with a cutter head 31 having a plurality of cutter elements 32 rotatably mounted thereon. The inner surface of the housing or sub 30 is provided with latching recesses 33 and a shoulder 34 on which the body 35 of the auxiliary bit 27 is adapted to be seated. The auxiliary bit body 35 is provided with spring-loaded outwardly-extendible latches or dogs 36 adapted to latch in recesses 33 on the inner wall of the sub 39. The latches 36 are connected, as by linkage members 37, to a stem 38 which is normally urged downwardly by a spring 39 so that the latches 3d are urged outwardly. The top of the stem 38 is in the form of a fishing head 40 adapted to be engaged by any suitable type of fishing tool 41 (FIGURE 5) for Withdrawing the bit from the lower end of the pipe string or drill string 21 or for inserting it into the lower end thereof.

In originally drilling the first portion of the well or hole 42 (FIGURE 1) in the ocean floor, the drill bit 25 may be of any type and not one that necessarily has a removable auxiliary bit secured to it. After drilling the hole 42 to the desired depth as shown in FIGURE 1, the drill string 21 and the bit 25 is removed from the hole (FIGURE 2) and withdrawn to the vessel. This operation takes place in the event that the drill bit 25 has become dull and must be changed or in the event that it is desired to lower a Well conductor or foundation pipe into the hole 42 in the ocean floor before proceeding with further drilling.

In the event that further drilling of the hole 42 is to be carried out, a pipe string 43 (FIGURE 3) is made up at the vessel 11 which may be similar or identical to the drill string 21 with the exception that, instead of having any type of bit 25 attached to the lower end thereof, a bit housing or sub 36 would be secured thereto. In well operations it is well known that a pipe string or drill string is made up by threadedly connecting together several short (say, 30 feet) sections of pipe together to make a pipe string of the desired length. Several of the bottom sections of pipe may be thick-walled pipe in the form of drill collars, if desired. With the lower end of the pipe string 43 positioned near the ocean floor 13, as illustrated in FIGURE 3, a well-detacting device in the form of a television camera, for example, is dropped through the pipe string or lowered therethrough on a cable.

The television camera represented in FIGURE 3 by numeral 44-, is shown in greater detail in FIGURE 7. One form of the television well-finding assembly comprises a body member 45 having outwardly-extending latches 46, linkage members 47 and a spring-loaded stem 48 similar to

elements

36, 27 and 38 on the removable drill bit body 45 of FIGURE 9. Thus, an upward pull on the cable 5-9 secured to the top of the stem 48 will cause the latches 46 to be retracted from the recesses 33 in the sub 3% so that the television assembly can be withdrawn from its seated position on shoulder 34.

In order to allow use of the apparatus of the present invention in pipe strings of relatively small diameter, the body of the television assembly is provided with a television camera 59 which is preferably arranged in a vertical or downwardly-directed position above a vertically-directed recess 51 in the lower end of the body member 45. The lower end of the body member 45 may be tapered, as at 52, to facilitate entry of the apparatus in a well or in the top of a pipe already positioned in the well. Although the downwardly-directed television camera may be used satisfactorily to find a hole or well bored in the ocean floor, the well-finding apparatus of the present invention is made more versatile by the mounting of a mirror 53 below the television camera 5%. The mirror 53 is preferably mounted for movement in a vertical plant about a horizontal axis by pivot pin 54. The position of the pivot pin 54 and of the mirror 53 attached thereto may be selectively changed by any suitable remotely-controlled operator, such for example as a Selsyn motor 55 (FIGURE 8) carried by the body member 45. A control cable 56 from the Selsyn 55 extends through the body member 45 and may be connected to the leads or control cable 57 which is adapted to transmit current to and signals from the televisions camera 50. The cable 57 in turn passes 29 through an enlarged portion of the stem 43 as a weight bar 58 and then upwardly to a point where it forms part of the cable 49 which is preferably both a load-supporting and signal and current-transmitting cable.

In order to illuminate the area below the elevision camera the body member 55 is provided with suitable light means, such for example as a downwardly-directed iiood light 59 having a current lead 60. Additionally, the downwardly-extending portion of the body member 45 may be provided with the one or more annular or helically-shaped light sources 61 which are positioned in a recess 62 in the outer wall of the body member 45. The back of the recess 51 in the lower portion of the body member 45 is shaped in a manner such that the mirror 53 fits flush against it when in a vertical position, thus giving an unobstructed view from the television camera 59 in a vertical direction. The use of a variable angle mirror 53 is more advantageous in locating a structure such as a wellhead positioned above the ocean floor than in locating merely a hole in the ocean floor.

To facilitate movement of the lower end of a depending pipe string, the lower end of the pipe string is provided with an outwardly-directed unidirectional port through which fluid may be discharged. As shown in FIGURE 7 this port 63 may be contained in the television assembly body member 45. It is preferably directed in a direction opposite to that in which the mirror 53 is looking when the mirror is used. The upper end of the port 63 is in communication through chamber 64 and flow passage 65 with the interior 66 of the pipe string 43. Thus, fluid being pumped down under pressure through the pipe strin 43 will be jetted out through the port 63 causing the lower end of the pipe string 43 to move laterally through the water, as shown in FIGURE 3, until it has assumed a position in register with the hole 42. After the pipe string 43 (FIGURE 3) ,is in register with the top of hole 42 in the ocean floor 13, it is moved downwardly into the hole until at least the lower end of the pipe string is in the hole 4-2. When the lower end of the pipe string 43 has assumed this position, as shown in FIGURE 4, the television assembly in withdrawn out of the pipe string by an upward pull on the cable 49 (FIGURE '7). After the television assembly has been withdrawn from the bottom of the pipe string, an auxiliary bit 27 (FIGURE 5) may be 1 wered on a wire line 65 into position at the bottom of the drill string. In soft formations the drilling operations may be carried out without the use of the auxiliary bit 2? bein; positioned in place. Gne suitable type of drill bit for use with the present invention is a Reed Roller Bit Company BR wire-line retractible core cutter and drill bit assembly illustrated on pages 423-74 of the 1962-63 Composite Catalog of Oil Field Equipment and Services.

When the pipe string 43 is positioned in the hole 42 in the ocean floor i3 as shown in FIGURE 4, with the television assembly withdrawn from the lower end of the pipe string, the pipe string may be used as a guide along which a well conductor or foundation pipe 5'7 (FIGURE '6) may be lowered and guided into the hole 42 where it may be cemented, if desired. As shown in FIGURE 6 the well conductor or foundation pipe 67 is provided with a funnel-shaped top 63 and a base plate 59 adapted to rest on the ocean floor 13. To re-estaolish a connection between the vessel 11 on the surface or" the water 12 and the foundation pipe 67, the upper end of the pipe string 4-3 is suspended from the vessel either from the rotary table 22 or a connector unit 213 such as a power swivel which is well known to the art. Whatever the manner of suspension of the pipe, the upper end of the pipe 43 is connected by a hose "ill to a suit-able pump '71, such as a mud pump positioned on the vessel 11. If the vessel 11 is not directly over the foundation pipe 67 one method of moving the lower end of the pi e string 43 is to start pumping fluid down the pipe 4-3 and out the horizontally disposed port 63 in the lower end thereof so that it is jetted substantially horizontally, as at 72. The jet action will cause the lower end of pipe 43 to bend away from its normally vertical suspended position since an elongated pipe, say 300 feet long, of small diameter is relatively flexible. The lateral distance that the lower end of the pipe 43 moves can be varied by varying the pump pressure at the vessel. At the same time the upper end of the pipe can be slowly rotated from the vessel, as by securing it in the rotary table 22 and slowly moving the rotary table until the television assembly 44 in the lower end of the pipe string 43 has had a chance to scan a circular area of the ocean floor beneath the vessel 11. In the event that the foundation pipe 67 (FIGURE 6) is not found on the first circle scanned by the television assembly 4 the pump pressure can be increased .to increase the jetting action at 72 causing the lower end of the pipe to be deflected a greater distance from its vertical position so that when it is rotated at the top the television assembly will sweep a larger concentric area than the previous area scanned. In this manner the well or well head is located.

In the event that the pipe string 43 was to be used only to act as a guide to insert a foundation pipe in the ocean iioor, it may not of necessity be provided with the bit housing or sub 3 -1). Instead the lower end of the drill pipe 43 could be in the form shown in FIGURES l0 and 11 of the drawing. Thus, in FIGURE 10 the lower end of the pipe string 4-3 is shown as being provided with a port 73 in the side wall thereof that is horizontally directed. It is normally closed by a sleeve valve '74 normally held in an upward position by compression spring 75. The lower end of the pi e 43 may be provided with a suitable aligning means which may be in the form of a short pipe section 76 having a sloping shoulder 77 tapering from a point at one side down to an orienting notch 78 at the bottom. Thus, in dropping a television or other assembly down through the pipe string 43 or lowering it by means of a fishing head 41 as shown in FIGURE 10, an outwardly extending lug or pin 79 on the outer surface of the television body member 86 will contact the shoulder 77 at any point and slide down along the shoul der into notch 78 to the positionillustrated in FIGURE 11. The orienting means with the aligning notch 73 is employed in the event that it is desired to position the tiltable mirror 5'3 of the television assembly so that it is aimed in the opposite direction from the jet port 73 in the wall of the pipe string 43. When the television unit 84 of FIGURE 11 is seated in place, a flange 81 rests on top of valve 74 pressing it downwardly to compress spring '75 and open port 73 so that fiuid being pumped down pipe string 43 will be discharged and jetted out the port '73.

While the method of the present invention has been descr bed with regard to using television apparatus for 10- eating a well or hole in the ocean fioor, it is to be understood that other well locating devices well known to the art could also be used. Thus, after drilling a well to a desired depth and removing the auxiliary bit 27 i from the end of the drill string or pipe string 4-3 as shown in FIGURE 5, any suitable well-marking device could be dropped down through the pipe string 43 and out the lower end thereof and into the borehole &2. As shown diagrammatically in FIGURE 12, a seismic energy generating source 82, known as a transponder, could be dropped through the pipe string 43 being pulled therethrough by a weight 83 which would rest on the bottom of the borehole 42 and be connected to thetransponder 82 by an anchor line 34 substantially equal to the depth of the well. With the transponder in a buoyant container it would be positioned over the mouth of the well.

In locating an .underwaterwell having a transponder 82 .1 positioned in such a manner, the television assemblyC (FIGURE 10) would be replaced bya suitable logging instrument well known to, the art having a' transmitter and receiver unit. The transmitter unit may be in the form of a spark gap adapted to emit a seismic signal while the receiver would be any suitable type of pressure detector, hydrophone, crystal detector, etc. The transmitter and receiver would be connected by means of a cable similar to 49 (FIGURE 7) running up to the vessel.

- When a seismic impulse is transmitted by the transmitter 83 it is picked up by the receiver 84 and by the transponder 82 triggering the transponder to put out a similar seismic signal. The time interval between the signals coming from the transponder 82 and the transmitter 83 are measured and the pipe string 43 is moved in any suitable manner to a new position. Movement of the pipe 43 is continued until the time delay between the signals received from the transponder 82 and the transmitter 33 reaches Zero at which time the lower end of the pipe 43 is over the transponder 82 in the mouth of the well 42. The pipe 43 can then be lowered into the well. When drilling operations were resumed the transponder 82 and its anchor 83 would be ground up by the bit. The transmitter 83 and the receiver 84 would be mounted on the body member similar to element 8% in FIG- URE 10.

The electrical leads carried by the weight-supporting and signal and current-transmitting cable 49 (FIGURE 7) are connected at the surface to a suitable indicating device, recorder, viewing screen, etc. 85, depending upon the type of well-findin g unit being employed in the lower end of the pipe string to locate the well. While the television assembly of FIGURE 7 has been described with regard to having a mirror 53 mounted on a horizontal axis below the television camera 50, it is to be understood that the television well-finding assembly may be used without the mirror. Additionally, a wider range of vision for the television camera 50 may be obtained by cutting away the body member 45 below the television camera t Also, instead of mounting the mirror 53 in a horizontal pivot, a mirror placed at a fixed angle, say 30 degrees from the vertical, may be positioned below the television camera and rotated on a vertical axis to scan the ocean floor to the side of the lower end of the pipe.

We claim as our invention:

1. A method of locating and establishing contact with an underwater well from a vessel on the surface of a bod of water, said method comprising 1 (a) positioning a drilling vessel at a selected offshore location (b) making up at the vessel a pipe string having an axial opening in the lower end thereof,

(c) lowering the lower end of said pipe string from said vessel to a position near the ocean floor beneath said body of water,

(d) lowering down through said pipe string and positioning in the lower end of said pipe string well finding means operatively connected to indicating means on said vessel (e) moving said pipe string and said well finding means means to scan the ocean floor and locate the top of the well drilled in said ocean floor and to position the lower end of the pipe string in register thereabove, and

- (f) lowering said pipe string until at least the lower end thereof is in the Well.

2. A method of locating establishing contact with an underwater well from a vessel on the surface of a body of Water, said method comprising (a) positioning a drilling vessel at a selected offshore location (b) making up at the vessel a pipe string having an axial opening in the lower end thereof,

(0) lowering the lower end of said pipe string from he ocean floor beneath (d) lowering through said pipe string and a register with the opening in the lower end thereof television camera means operatively connected to viewing ,means on said vessel,

(e) moving said pipe string and said camera means to scan the ocean floor while observing said viewing means on said vessel to locate the top of the well drilled in said ocean floor and position the lower end of the pipe string in register thereabove,

(f) lOWeTing said pipe string until at least the lower end thereof is in the well, and

(g) withdrawing said camera means back to the vessel.

3. A method of drilling an underwater well from a vessel on the surface of a body of water, said method comprising (a) positioning a drilling vessel at a selected offshore location (b) lowering from said vessel into contact with the ocean floor beneath the body of water the lower end of a drill string including a bit secured to the lower open end thereof,

(c) forming a hole in said ocean floor while advancing said drill string thereinto,

(d) Withdrawing said drill string to said vessel,

(e) making up at the vessel a pipe string having an axial opening in the lower end thereof,

(f) lowering said pipe string from said vessel to a position near the ocean floor beneath said body of water,

(g) lowering through said pipe string and in register with the opening in the lower end thereof television camera means operatively connected to viewing means on said vessel,

(h) moving said pipe string and said camera means to scan the ocean floor to locate the top of the hole drilled in said ocean floor and position the lower end of the pipe string in register thereabove,

(i) lowering said pipe string until at least the lower end thereof is in the hole, and

(j) withdrawing said camera means back to the vessel.

4. The method of claim 3 including the steps of (k) subsequently lowering a drill bit through said pipe string and partially out the opening in the lower end thereof,

(1) securing said drill bit to the lower end of the pipe string, and

(m) continuing drilling of the hole in the ocean floor.

5. The method of claim 1 wherein the pipe moving step includes the step of moving at least the lower end of said pipe string together with said well-finding means to scan the surface of the underwater ocean floor to locate the hole drilled therein.

6. The method of claim 5 wherein said pipe string is rotated from the upper end thereof.

7. The method of claim 5 wherein the lower end of the pipe string is displaced laterally from a normally vertical depending position.

8. The method of claim 7 including the step of at least partially rotating the upper end of said pipe string to cause the lower end thereof to move through an arc.

9. The method of claim 7 including the steps of pumping a fluid under pressure from said vessel down said pipe string and discharging said fluid laterally from the lower end of said pipe string in one direction.

10. Apparatus for locating and establishing contact between a vessel on the surface of the ocean and a hole in the ocean floor, said apparatus comprising a pipe string depending from said vessel with the lower end of the pipe string near the ocean floor,

means on said vessel for suspending said pipe string near its upper end,

television mean carried at least partially within said pipe string at the lower end thereof and television receiving means carried on said vessel for viewing the area around thelower end of thepipe string,

1 acabl-extending from said'television means upwardly through said pipe string to the television receiving means on the vessel at the surface, and means for moving said pipe string relative to said ocean.

11. The apparatus of claim 10 including latch means for latching said television means within said lower end of said pipe string, one portion of said latch means being carried by the inner Wall of said pipe string and a cooperating portion of said latch means being carried outwardly by said television means.

12. The apparatus of claim 11 wherein one portion of said latch means comprises latching recess means in the inner Wall of said pipe string and the other portion of said latch means comprises radially extensible latch elements of a size to engage said latching recess means.

13. The apparatus of claim 10 including means closing of the lower end of said pipe string and a substantially laterally-directed fluid discharge port carried near the lower end of said pipe string and in communication with the bore thereof whereby fluid pumped down said pipe as string may be jetted therefrom.

M. The apparatus of claim 13 including pump means carried on the vessel and connected to the upper end of said pipe string for pumping fluid therethrough.

15. The apparatus of claim 14 including pipe rotating means carried by said vessel and operatively engaging said depending pipe string for rotating said pipe string.

References Cited by the Examiner UNITED STATES PATENTS CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner.

Claims

1. A METHOD OF LOCATING AND ESTABLISHING CONTACT WITH AN UNDERWATER WELL FROM A VESSEL ON THE SURFACE OF A BODY OF WATER, SAID METHOD COMPRISING (A) POSITIONING A DRILLING VESSEL AT A SELECTED OFFSHORE LOCATION (B) MAKING UP AT THE VESSEL A PIPE STRING HAVING AN AXIAL OPENING IN THE LOWER END THEREOF, (C) LOWERING THE LOWER END OF SAID PIPE STRING FROM SAID VESSEL TO A POSITION NEAR THE OCEAN FLOOR BENEATH SAID BODY OF WATER, (D) LOWERING DOWN THROUGH SAID PIPE STRING AND POSITIONING IN THE LOWER END OF SAID PIPE STRING WELL FINDING MEANS OPERATIVELY CONNECTED TO INDICATING MEANS ON SAID VESSEL (E) MOVING SAID PIPE STRING AND SAID WELL FINDING MEANS MENS TO SCAN THE OCEAN FLOOR AND LOCATE THE TOP OF THE WELL DRILLED IN SAID OCEAN FLOOR AND TO POSITION THE LOWER END OF THE PIPE STRING IN REGISTER THEREABOVE, AND (F) LOWERING SAID PIPE STRING UNTIL AT LEAST THE LOWER END THEREOF IS IN THE WELL.

10. APPARATUS FOR LOCATING AND ESTABLISHING CONTACT BETWEEN A VESSEL ON THE SURFACE OF THE OCEAN AND A HOLE IN THE OCEAN FLOOR, SAID APPARATUS COMPRISING A PIPE STRING DEPENDING FROM SAID VESSEL WITH THE LOWER END OF THE PIPE STRING NEAR THE OCEAN FLOOR, MEANS ON SAID VESSEL FOR SUEPENDING SAID PIPE STRING NEAR ITS UPPER END, TELEVISION MEAN CARRIED AT LEAST PARTIALLY WITHIN SAID PIPE STRING AT THE LOWER END THEREOF AND TELEVISION RECEIVING MEANS CARRIED ON SAID VESSEL FOR VIEWING THE AREA AROUND THE LOWER END OF THE PIPE STRING, A CABLE EXTENDING FROM SAID TELEVISION MEANS UPWARDLY THROUGH SAID PIPE STRING TO THE TELEVISION RECEIVING MEANS ON THE VESSEL AT THE SURFACE, AND MEANS FOR MOVING SAID PIPE STRING RELATIVE TO SAID OCEAN.