US3243001A

US3243001A - Rotary well drilling device

Info

Publication number: US3243001A
Application number: US331158A
Authority: US
Inventors: Renic P Vincent
Original assignee: Pan American Petroleum Corp
Current assignee: Pan American Petroleum Corp
Priority date: 1963-12-17
Filing date: 1963-12-17
Publication date: 1966-03-29
Anticipated expiration: 1983-03-29

Description

March 29, 1966 R. P. VINCENT ROTARY WELL DRILLING DEVICE 4 Sheets-Sheet 1 Filed Dec. 17, 1963 RENIC F. VINCENT INVENTOR.

ATTORNE Y March 29, 1966 R. P. VINCENT ROTARY WELL DRILLING DEVICE 4 Sheets-Sheet 2 Filed Dec. 17, 1963 FIG. 6

RENIC P. VINCENT INVENTOR.

ATTORNEY March 29, 1966 Filed Dec. 1'7, 1963 R. P. VINCENT ROTARY WELL DRILLING DEVICE 4 Sheets-Sheet 3 RENIC R VINCENT INVENTOR,

ATTORNEY March 29, 1966 v c 3,243,001

ROTARY WELL DRILLING DEVICE Filed Dec. 17, 1963 4 Sheets-Sheet 4 36 FIG.IOA F|G.|OB

\ INVENTOR.

RENIC P. VINCENT FIG-IO 8Y2! ATTORNEY.

United States Patent Delaware Filed Dec. 17, 1963, Ser. No. 331,153 16 Claims. (Cl. 175-73) This application is a continuation-in-part of my application for Letters Patent of the United States, S.N. 159,630, filed December 15, 1961, now abandoned.

My invention concerns a tool for use in drilling wells by the rotary method. The tool controls the path of the drill. It utilizes the pressure of the drilling fluid to operate fluid motors which position the drill stem relative to the axis of the hole to guide the drill bit in the desired direction. The flow of high-pressure drilling fluid is diverted to appropriate fluid motors by a unique pendulum and valve arrangement.

Rotary drilling rate is greatly handicapped in some areas owing to the presence of geological formations which cause the drill bit to veer from the vertical. Such areas are commonly referred to as crooked hole country. Several methods have been used to reduce the amount of hole deviation. For one thing, the amount of weight on the bit has been reduced by keeping a greater than normal portion of the drill string in tension. This decreases compressive forces and bending in the drill pipe. It has the disadvantage that the drilling rate drops appreciably when the weight on the bit is decreased. A method which is frequently used is that of placing additional drill collars and stabilizers in the lower end of the drill string to increase the stiffness of the drill string, and to take advantage of the greater vertical force resulting from the greater concentration of weight near the bit. These methods are successful to some extent; however, they do not permit full utilization of the available weight on bit when drilling in crooked hole country."

On some occasions it is desirable to drill wells which are not vertical. In marine locations, several wells are sometimes drilled from a single platform with the wells angling out in different directions from the platform. Also, where an oil-bearing formation is near the shore, the wells are sometimes drilled with the rig on the land and the well curved so that the oil zone is penetrated below the water-covered area. Directional drilling is also used near salt domes to reach an oil-bearing structure at the flank of the dome without having to drill through the salt plug.

It is therefore an object of my invention to provide a rotary drilling tool which will maintain the drill bit on a desired course. In one embodiment of my invention it is an object to provide a straight hole drilling tool which will reduce the tendency of the bit to drill off vertical. Another embodiment of my invention has for its object the provision of a directional drilling tool which will force the bit to drill at a desired deviation from vertical. It is a further object to utilize a portion of the hydraulic power in the drilling fluid to guide the bit along the desired path. Another object is to provide a valve system in this drilling tool which is substantially unaffected by normal rotary speeds of the drill pipe and by fluid flow through the tool.

My invention will be described by reference to the following drawings which illustrate various embodiments for reducing deviation from vertical and for directional drilling.

FIGURE 1 is a view, in cross section, showing the arrangement of the various components of the tool.

FIGURE 2 is a sectional View at 22 in FIGURE 1, illustrating the valve suspension element.

See

FIGURE 3 is a sectional view of the upper portion of the valve assembly, taken along line 3-3 in FIGURE 1.

FIGURE 4 shows the lower portion of the valve assembly at line 44 in FIGURE 1.

FIGURE 5, a sectional view along 5-5 in FIGURE 1, shows one embodiment of the pistons which force the bit toward a vertical alignment when the hole drifts off vertical.

FIGURE 6 shows a preferred design for ports in the drilling fluid distribution system.

FIGURE 7 further illustrates the ports of FIGURE 6, and their associated flow control equipment when the tool is positioned at a substantial deviation from vertical.

FIGURE 8 is a sectional view of a portion of the tool arranged for directional drilling.

FIGURE 9, a sectional view at 99 in FIGURE 8, illustrates one of the plates which can be used in the directional drilling tool.

FIGURE 10 illustrates a vertical section of a portion of the tool showing a preferred piston arrangement.

FIGURE 10A is an enlarged fragmentary section illustrating means attaching the bearing member to the end of the piston shown in FIGURE 10.

FIGURE 10B is a surface view of the outboard end of the fragmentary section of FIGURE 10A.

FIGURE 11 is a sectional view taken at line 1111 of the tool of FIGURE 10.

Referring to the above figures for a description of the apparatus, pendulum 13 in housing 11 is supported on pliant cable 16. Perforated plate 18, seated between couplings 2G and 21, anchors the cable and supports the pendulum. At the lower end of the pendulum, ring 14 connected to the pendulum by supports 15, is suspended a short distance above bottom 34 of housing 11.

Ports

25, 25 and 25" provide fluid access from housing 11 to conduits 27, 27 and 27" extending through the bottom of the housing. Orifices 26, 26 and 26" in the lower ends of the conduits provide a pressure drop when fluid is flowing through the conduits.

Cylinders

28, 28 and 28 extend from the conduits, through the axis of the tool to the opposite side of the housing. Piston 29 is shown in cylinder 28 in FIGURE 1. Similar pistons are in

cylinders

28 and 28". A force transmitting member, such as push rod 30, transmits the movement of piston 29 to sleeve 12 surrounding the housing. As shown in FIGURES 1, 5 and 8, each push rod is mounted in a recess in the outboard end of each piston. Each recess has a rounded bottom, and the inboard end of each push rod is rounded to fit the bottom of the recess so that the push rod may rotate and prevent seizure with the inside of the sleeve. Each rod is inserted into a recess and ex tends outwardly toward the inside wall of sleeve 12 so that fluid pressure in the cylinder causes the piston and push rod to move outwardly against the sleeve. The length of the push rods in their respective recesses are such, in respect of the clearance between housing 11 and sleeve 12, that the push rods are maintained in place even though no fluid is flowing through the tool. The recesses may be tapered slightly toward the bottom, if desired, to permit a slight movement of the push rods therein. As shown in FIGURES 10 and 11, an arrangement utilizing a diaphragm and roller bearing is employed in connection with the pistons to transmit the force to the sleeve. This latter embodiment, described hereinbelow, has been found preferable to the push rods described above for use in tools for reducing deviation from the vertical and for directional drilling tools.

In FIGURE 4, it is seen that

ports

25, 25' and 25" lie in a circle about the axis of the tool with their centers spaced apart. Sleeve 12 surrounding housing 11 is pivotally supported between upper end 23 of the housing and lower shoulder 22 of the coupling 20. Splines 35 between coupling 20 and lip 24 of the sleeve cause the sleeve to rotate with the tool. Wear rings 33 around the lower end of the sleeve reduce the wear on the sleeve as it rotates against the side of the well.

In using this tool with rotary drilling equipment, the tool is installed in the drill string, preferably immediately above the bit. Thus the drill bit would be connected to lower joint 36 and the drill pipe or drill collars would be attached at upper joint 37. Drilling fluid pumped down the drill pipe enters coupling 21 and passes through ports 19 in plate 18, then flows through ceupling 20 and housing 11. The drilling fluid flows around pendulum 13, then between ring supports 15 and through the center of ring 14. When the tool is vertical, the ring covers the outer portions of

ports

25, 25' and 25 as shown in FIGURE 3. In this position, the drilling fluid flows to each of the ports in substantially uniform proportions. The pressure drop is approximately the same through each of

orifices

26, 26, and 26" owing to this uniform distribution of drilling fiuid. The fluid discharged at the orifices passes through the bit and circulates to the surface by way of the annular space between the drill tools and the well walls.

Fluid motors operated by the drilling fluid adjust the position of housing '11 in relation to sleeve 12 and the inclination of the well. The pressure of the drilling fluid in conduit 27 and cylinder 28 displaces piston 29 toward the outer end of the cylinder owing to the lower pressure of the drilling fluid in the annulus. Push rod 39 transmits the piston displacement to sleeve 12. In the neutral position illustrated, substantially equal pressures are ap plied to

pistons

29, 29' and 29 whereby

push rods

30, 31 and 32 exert equal forces against sleeve 12.

When the well is not vertical, the housing is eccentric with respect to the pendulum. Ring 14 does not cover an equal portion of

ports

25, 25 and 25". This produces a nonuniform distribution of drilling fluid through

conduits

27, 27' and 27" and their orifices. The highest pressure will prevail in the conduit having the highest flow rate so that the piston and push rod associated with that conduit will exert a greater pressure against sleeve 12 than the other pistons and push rods. The result is that housing 11 moves to a position which is eccentric with respect to sleeve 12. For example, if the lower end of the housing were moved to the right in FIGURE 1, port 25 would be uncovered, permitting an increase in the flow through conduit 27. The increased fluid pressure would cause piston 29 to move to the right, thus displacing the housing toward the left side of sleeve 12. The over-all tendency is for the housing to be displaced in the direction wherein it becomes concentric with the vertically aligned ring and pendulum. As the tool rotates in an inclined hole,

ports

25, 25' and 25" rotate through a path eccentric to ring 14, thus alternately increasing and decreasing the flow through each port. As a port approaches the high side of the hole, an increasingly greater portion of its area is obstructed by the ring. The area covered, that is, the flow restriction, reaches a maximum when the port is at the highest side of the hole. As the port rotates flrom the high side to the low side of the hole, it approaches the central open portion of the ring, thereby reducing the restriction to flow until the port reaches the low side of the hole where the greatest area is unobstructed by the ring. When the deviation of the hole from vertical is slight, there will be little variation in the distribution of fluid to the ports. At large deviations there are much greater variations of flow through the ports which produce greater forces tending to move the housing into vertical alignment. The ports may be designed so that the flow through each conduit will vary from to 100 percent of the total flow through the tool as the tool rotates at or above a particular degree of inclination.

I have shown the movement of the pistons 29 in the cylinders 28 to be radially outward, parallel to the radius of housing 11 and against sleeve 12, so that the sleeve is forced outwardly to an eccentric position in respect of the housing in a direction approximately 180 from the direc tion of movement of the pendulum to an eccentric position in respect of the housing. However, the cylinders may extend outwardly and/ or the force transmitting members may move outwardly along a line .angularly displaced from the radius to displace the sleeve in a desired direction, typically between about and 200 from the direction of pendulum movement, depending upon the amount of lead or la-g required. For example, it might be desirable to provide a 10 lead to compensate the lag caused by the resistance of the drilling fluid to the rotation of the pendulum.

FIGURES 6 and 7 illustrate a preferred design of the drilling fluid valve assembly which produced the maximum force on the force transmitting members. In FIGURE 6, ring 14 is concentric with housing 11 as when the tool is in a vertical position. "

Ports

25, 25 and 25" are covered in equal amounts by ring 14, thus equal pressure prevails in the conduits

adjacent cylinders

28, 28' and 28". Each of the force transmitting members bears against sleeve 12 with approximately equal force, thereby maintaining housing 11 concentric with sleeve 12. FIG- URE 7 shows the position of ring 14 in relation to

ports

25, 25' and 25" when the tool is at an inclination whereby pendulum 13 hangs against the side of housing 11. Port 25 is entirely uncovered whereas ports 25' and 25 are completely covered by ring 14. Thus the maximum pressure available is exerted at this time on sleeve 12 by push rod 30, whereas

push rods

31 and 32 are exerting practically no pressure. As the tool rotates in a clockwise direction with ring 14 remaining in a substantially fixed position, port 25" moves into the central opening through ring 14, admitting an increasing amount of fluid to that port. Simultaneously port 25 moves to a position under the ring. In this manner the force on push rod 30 is gradually diminished and that on push rod 31 increased. When the inclination of the tool is at a smaller angle and ring 14 does not contact housing 11, none of the ports are completely closed or opened. Thus, the apparatus in FIGURE 7 at a smaller angle would shift ring 14 to the right a slight distance where it would cover a portion of port 25, reducing the force on push rod 30. Additionally, ports 25' and 25" would be partly uncovered whereby

push rods

31 and 32 would exert a force opposing that of push rod 30. From the foregoing it can be seen that the minimum angle of hole inclination at which the maximum force will be developed to push the housing and bit toward the low side of the hole is a function of the length of the pendulum and the difierence between the radius of the inner edge of ring 14 and the radius of the outer edges of the ports. Thus, for a given ring and port design, the tool can be made to control deviation within a smaller angle by increasing the length of the pendulum.

This apparatus has been described with

ports

25, 25' and 25" positioned to receive fluid through the center of ring 14. It should be understood that these ports can be arranged to receive drilling fluid around the outside of ring 14. In such an arrangement, the ports should be in approximately vertical alignment with the push rods, rather than offset 180 as shown in FIGURE 1, in order that the force transmitting members may move outwardly against the sleeve 12 in a direction substantially opposite that of the pendulum movement with respect to housing 11.

On the other hand, the ring and ports may be arranged in relation to the pistons and push rods whereby the force pushes the housing away from the low side of the hole. This arrangement will be useful in drilling directional wells. FIGURES 8 and 9 show an arrangement which can be used to adjust the angularity of

ports

25, 25' and 25" in relation to their

corresponding conduits

27, 27 and 27". The lower end of housing 11 contains a stack of oriented plates of the type shown in FIGURE 9. Plate 39 at the top of the stack has ports in the arrange-ment shown in FIGURE 6 for eflicient valve action. Plates 4t), 41, 42, 43, and 44, which have identical shapes, are held in place below plate 39 by bolts 38. These plates are positioned in FIGURE 8 so that conduits 27, 27' and 27spiral through an angle of 180 between the inlet ports and

cylinders

28, 28 and 28". In FIGURE 9 it is seen that

conduits

27, 27' and 27" have an elongated, curved cross section. The centers of the circular ends of the cross-section of the conduits are separated radially by an angle of 36 so that the five plates can be stacked in the housing to produce a continuous conduit which spirals through an angle of 180 and enabling an angular displacement of 180 between each port and its associated cylinder. Thus, in the apparatus shown in FIGURE 9, when the drill stem is slanted so that the pendulum is near the right side of the housing, ring 14 clears port 25 and cove-rs ports 25' and 25". The increased flow of drilling fluid through conduit 27 produces an increased force between push rod 3i) and housing 12.. This urges the housing and drill bit further in the direction which it has already moved from vertical. This embodiment of my invention is useful in maintaining a well in a diverted course. The plates would be bolted in the housing with substantially no angularity between them when it is desired to drill :a vertical well, A small angular displacement up to about between the ports and their associated cylinders can be set to compensate the lag of the pendulum in the housing.

In using this tool for directional drilling, the well may be first diverted in the desired direction, for example, by placing a whipstock in the well. The drill string is then run into the well with the directional tool above the bit and drilling commenced off the face of the whipstock. When the tool is deflected in this manner, the pendulum will operate the valve so that the push rods force the housing toward the high side of sleeve 12 and the well, thus maintaining the deflection.

Again referring to FIGURES 6 and 7,

ports

25, and 25 have circular outer edges and cuspal inner edges composed of two circular segments. The radius of curvature r of these edges is equal to that of the inner edge of ring 14. Radial axes 45, and 45" of these ports are spaced 120 apart in the bottom of housing 11. In FIGURE 7, it is seen that the outer edge of port 2E, for example, lies directly below the inner edge of ring 14 when the outer edge of the ring touches the housing on radial axis 45 of port 25. In this position, the inner edge of the ring also lies directly above the segments of the inner edges of ports 25' and 25 which are nearest port 25. In this manner the inner edge of ring 14 defines the position of the remaining segments of the ports when the outer edge of the ring contacts the housing at radial axes 45' and 45" of ports 25' and 25", respectively. Thus, the circular outer edge of port 25 and the adjacent segments of the cuspal inner edges of ports 25' and 25" have a common center of curvature, located on radial axis 45 a distance d from the axis of housing 11. Distance d is the maximum displacement or amplitude of ring 14 on the pendulum.

It is desirable for the shape of the ports to be such that approximately one-third of the area of each port is not covered when the ring is concentric with the housing. This arrangement permits a substantially uniform rate of flow through the apparatus, regardless of the position of the pendulum and ring.

A unique means for supporting the pendulum has been devised. Both pivoted and journaled supports were found to be unsatisfactory. There is a substantial pressure drop across the pendulum and ring at the high rates of fluid circulation which must be used. The friction in the pivoted and journaled supports at the high pressure drop causes the pendulum to tend to hang in one position as the tool is rotated. I prefer to use a flexible support 6 which is substantially frictionless and inelastic. Support cable 16 is composed of multiple strands of a smalldiameter wire or rod. The strands should be straight rather than twisted to reduce stretch. Cable anchor 17 is adjusted so that ring 14 swings free of housing bottom 34 while drilling fluid in flowing through the tool without permitting a substantial flow between the ring and bottom.

Another variation in design which can be used to obtain greater forces pushing housing 11 to the desired position with respect to sleeve 12 is that of using multiple cylinders and fluid motors in communication with each fluid conduit. The fluid motors operated from a common conduit should be in longitudinal alignment to produce the maximum force against sleeve 12. The piston and push rod in each cylinder will effectively multiply the force obtained with a single cylinder.

This apparatus is suitable for use with either gaseous or liquid drilling fluids. The size of orifice 26 can be selected to give the desired pressure drop with the particular drilling fluid being used.

Turning now to FIGURES 10 and 11, the above-described tool employing an alternate embodiment. of the force transmitting members has been found to be highly advantageous. In FIGURE 11, which is an enlarged section taken at line 11-11 of the housing shown in FIG- URE 10, only one piston 51 has been shown in place in cylinder 52 for the purpose of simplification. However, it will be understood that in practice similar pistons 51' and 51 are positioned in

cylinders

52 and 52", respectively. FIGURE 10A, an enlarged fragmentary section taken at the level of bearings 56, and FIGURE 1013, i1- lustrate the manner of attaching roller bearing member 56 to the outboard end of each of the pistons. In lieu of the piston and push rod design described above, the tool employs relatively thin, large diameter pistons 51 which move radially in cylinders 52, being actuated by fluid pressure in the corresponding conduits as described above. This piston arrangement enables a higher force to be applied to the sleeve for a given fluid pressure, while requiring a significantly lower pressure drop across the tool. Preferably, the pistons are fabricated from a mild steel, and steel lines 53 are employed in the cylinders 52 to reduce wear on the cylinders. Each cylinder is shaped to retain a flexible diaphragm member 54, typically a %-inch-thick neoprene diaphragm is placed on the inboard side of the pistons 51 and fitted tightly into the enlarged portion of each cylinder to provide a fluid-tight seal in the cylinder and prevent the escape of drilling fluid through the cylinders. On the outboard end of each piston there is positioned a roller bearing member 56 which may comprise parallel roller bearings positioned vertically on the piston and held in place by keepers 57. If desired, multiple short roller bearings may be employed in lieu of long rollers. Roller bearings 56 are positioned in elongated recesses 58 extending vertically along the outboard end of the pistons. Preferably, the back side of each recess is curved, with a radius the same as the radius of the sleeve 12 to enable pistons 51 to move in and out of the cylinders without rolling from side to side when the rollers engage the inside wall of the sleeve. As before, the movement of pendulum 13 and ring 14 apportions drilling fluid through the orifices and conduits, and the fluid pressure in the cylinders actuates the pistons therein to drive the pistons outwardly. The roller bearings contact the sleeve and transmit the outward force thereto so that the position of housing 11 is adjusted in relation to sleeve 12 as described hereinabove. Since this latter piston arrangement enables the tool to operate with a lower fluid pressure drop across the tool, central conduit 58 may be provided to provide adequate flow of drilling fluid to the bit. If desired, bumper ring 59 may be employed on the lower end of pendulum 13, utilizing O-rings 60, as shown, to absorb the impact of the pendulum striking the housing.

It can be seen that various modifications are possible within the spirit of my invention.

Therefore, I do not Wish to be limited to the specific embodiments disclosed herein. My invention should be construed according to the following claims.

I claim:

1. An apparatus for controlling the attitude of a drill pipe during the drilling of a well comprising:

a housing adapted to be installed in said drill pipe to form a portion thereof,

a sleeve surrounding said housing, said sleeve having an inside diameter greater than the outside diameter of said housing,

means for supporting the upper end of said sleeve on said housing whereby the lower end of said sleeve can be displaced radially from said housing,

fluid conduits through said housing,

gravity-sensitive means supported from said housing for apportioning drilling fluid flowing through said drill pipe to said fluid conduits in relation to the attitude of said housing, and

pressure-responsive means carried by said housing acting substantially radially to said housing for applying outward pressure on said sleeve proportional to fluid pressure in said conduits to force said housing outward in response to the position of said gravity-sensitive means.

2. An apparatus for controlling the attitude of a drill pipe during the drilling of a well comprising:

a housing adapted to be installed in said drill pipe and form a portion thereof,

a sleeve surrounding said housing, said sleeve having in inside diameter greater than the outside diameter of said housing,

means for supporting the upper end of said sleeve on said housing, whereby the lower end of said sleeve can be displaced radially from said housing,

fluid conduits through said housing,

a pendulously supported gravity-sensitive, multiple opening valve carried by said housing for apportioning drilling fluid flowing through said drill pipe to said fluid conduits in relation to the attitude of said housing, and

a plurality of fluid actuated motors carried by said housing, each connected to one only of said fluid conduits and adapted to apply radial pressure on said sleeve proportional to fluid pressure in said conduits to urge said housing away from said sleeve in response to the position of said gravity-sensitive means.

3. An apparatus for controlling the attitude of a drill pipe duringthe drilling of a well comprising:

a housing,

means for pivotally supporting the upper end of said sleeve on said housing whereby the lower end of said sleeve can move to a position eccentric to said housing,

fluid conduits through said housing, pendulum-actuated means in said housing for apportioning drilling fluid to said fluid conduits in relation to the attitude of said housing,

means for restricting fluid discharge from said conduits,

multiple cylinders in said housing, at least one of said cylinders communicating with each of said conduits, and pistons in said cylinders adapted for lateral extension from said housing to bear against said sleeve and move said housing in relation to the position of said pendulum-actuated means as fluid flows through said conduits.

4. The apparatus of claim 3 wherein said pendulumactuated means for apportioning drilling fluid includes:

a pendulum pliantly supported in said housing along the longitudinal axis thereof, i

a ring attached to the lower end of said pendulum, the lower surface of said ring lying in a plane parallel and in proximity to that of the bottom of said housing, the center of said ring lying on the longitudinal axis of said pendulum,

three fluid ports near the bottom of said housing beneath said ring and spaced apart therefrom to provide fluid access to said fluid conduits, said ports being substantially uniformly spaced in a circle about the axis of said housing, each of said ports having a circular outer edge and a cuspal inner edge consisting of two circular segments, each of said circular outer edge and inner edge segments having a radius equal to that of the inner edge of said ring, the center of curvature of said outer edge being in longitudinal alignment with the axis of said pendulum when said pendulum is displaced along the radial axis of said port the maximum possible distance from the axis of said housing, and the centers of curvature of said cuspal circular segments lying on the radial axes of adjacent ports when said pendulum is displaced the maximum distance along those radial axes.

5. Apparatus for controlling the attitude of a drill pipe during the drilling of a well comprising:

a housing,

fluid conduits through said housing,

a mass pliantly supported in said housing along the longitudinal axis thereof, fluid ports near the bottom of said housing beneath said mass and uniformly spaced in a circle about the axis of said housing, and a ring attached to the lower end of said mass and above said fluid ports whereby said ring alternately restricts fluid flow to said ports when said apparatus is rotated out of vertical alignment to apportion drilling fluid to said fluid conduits in relation to the attitude of said housing,

means for restricting fluid discharge from said conduits,

multiple cylinders in said housing, at least one of said cylinders communicating with each of said conduits, and pistons in said cylinders adapted for lateral extension from said housing to bear against said sleeve and move said housing in relation to the position of said pendulum-actuated means as fluid flow through said conduits.

6. An apparatus for controlling the attitude of a drill pipe during the drilling of a well comprising:

a cylindrical housing having a fluid inlet at the top and a substantially flat bottom,

a sleeve pivotally mounted on said housing and positioned around said housing, said sleeve having an inside diameter greater than the outside diameter of said housing and adapted for eccentric displacement in relation to said housing,

multiple cylinders in said housing with the axes of said cylinders normal to the axis of said housing,

a piston in each of said cylinders, said pistons being extensible to engage said sleeve,

multiple drilling fluid conduits through thebottorn of said housing, each of said conduits communicating with at least one of said cylinders,

an inlet port for each of said conduits, said ports lying in a circle in the bottom of said housing about the axis of said housing,

flow restricting outlets in said conduits,

a pendulum pliantly-supported in said housing,

a port closure ring attached to said pendulum whereby each of said inlet ports is covered an equal amount when said pendulum is axially aligned in said housing and the total area covered at any pendulum position being approximately equal to the area of one port.

7. The apparatus of claim 6 wherein said pliantlysupported pendulum includes:

a mass and a bundle of substantially inelastic, flexible fibers adatped to support said mass in said housing.

8. In the drilling of wells by the rotary method, an apparatus to control the deviation of the well from vertical comprising:

a housing, a loose-fitting sleeve surrounding said housing, the upper end of said sleeve being pivotally attached to the upper end of said housing whereby the lower end of said sleeve can move to a position eccentric to said housing,

multiple ports in the bottom of said housing uniformly spaced in a circle about the axis of said housing,

a fluid conduit extending from each of said ports through said housing,

a flow restriction at the outlet of each fluid conduit,

multiple cylinders in said housing with the axes of said cylinders substantially perpendicular to the longitudinal axis of said housing, at least one of said cylinders in fluid communication with each of said conduits, each cylinder angular-1y displaced substantially 180 from its associated port,

pistons in said cylinders,

force transmitting members on the outboard ends of each of said pistons for radial engagement with said sleeve,

a pendulum in said housing,

a pliant support for said pendulum, said support being anchored on the longitudinal axis of said housing,

a ring supported from the lower end of said pendulum and covering the outer portions of said ports when said tool is in the vertical position, the center of said ring being on the longitudinal axis of said pendulum,

means for passing drilling fluid to said ports,

a flat, lower face on said ring in flow-controlling relationship to said ports to control the flow of drilling fluid to said ports, whereby deviation from the vertical during drilling urges said sleeve outwardly from said housing in a direction substantially opposite from the direction of movement of said pendulum with respect to said housing.

9. The apparatus of claim 8 wherein said force transmitting members comprise push rods in the outboard end of each said pistons.

10. The apparatus of claim 8 including a diaphragm member in each said cylinders on the inboard side of the pistons positioned therein, said diaphragm member be ing actuated by fluid pressure to contact said piston and move said piston outwardly in its associated cylinder.

11. The apparatus of claim 10 wherein said force transmitting means comprises a roller bearing member on the outboard end of each of said pistons.

12. In the drilling of wells by the rotary method, an apparatus for defiecing the drill from a straight path comprising:

a housing,

a sleeve surrounding said housing and piovtally attached to the upper end of said housing whereby said sleeve can move to a position eccentric to the lower end of said housing,

multiple ports in the bottom of said housing,

multiple cylinders in said housing, each connected to one of said ports and angularly displaced substantially 180 from its associated port,

the axes of said cylinders being perpendicular to the axis of said housing,

pistons in said cylinders adapted to be radially displaced by fluid flowing through said apparatus,

force transmitting members on the outboard ends of said pistons for transmitting the movement of said pistons to said sleeve and to displace said sleeve to said eccentric position,

multiple conduits in said housing connecting each of said ports with its associated cylinder inboard of said pistons,

means for restricting fluid discharge from said conduits,

a pendulum in said housing,

a pliant support for said pendulum anchored on the longitudinal axis of said housing, and

a ring attached to the lower end of said pendulum and positioned in a plane parallel to the bottom of said housing whereby the flow of fiuid through said ports is controlled by the position of said ring and pendulum,

the movement of said pendulum during drilling producing an eccentricity of said housing in said sleeve approximately 180 displaced from the eccentricity of said pendulum in said housing.

13. The apparatus of claim 12 including:

a stack of circular plates secured in the bottom of said housing, each of said plates being provided with multiple elongated, curved openings extending therethrough, said openings being in flow communication with corresponding openings in adjacent plates to form continuous spiral conduits connecting each of said ports with its associated cylinder.

14. The apparatus of claim 12 wherein said force trans mitting members comprise push rods in the outboard end of each of said pistons.

15. The apparatus of claim 12 including a diaphragm member in each said cylinders on the inboard side of the pistons positioned therein, said diaphragm member being actuated by fluid pressure to contact said piston and move said piston outwardly in its associated cylinder.

16. The apparatus of claim 15 wherein said force transmitting means comprises a roller bearing member on the outboard end of each of said pistons.

References Cited by the Examiner UNITED STATES PATENTS 2,075,064 3/ 1937 Schumacher et al. l231 2,153,680 4/1939 Schumacher et a1. 231 3,043,381 7/1962 McNeely 175-73 3,141,512 7/ 1964 Gaskell et al 17573 X CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

Claims

1. AN APPARATUS FOR CONTROLLING THE ATTITUDE OF A DRILL PIPE DURING THE DRILLING OF A WELL COMPRISING: A HOUSING ADAPTED TO BE INSTALLED IN SAID DRILL PIPE TO FORM A PORTION THEREOF, A SLEEVE SURROUNDING SAID HOUSING, SAID SLEEVE HAVING AN INSIDE DIAMETER GREATER THAN THE OUTSIDE DIAMETER OF SAID HOUSING, MEANS FOR SUPPORTING THE UPPER END OF SAID SLEEVE ON SAID HOUSING WHEREBY THE LOWER END OF SAID SLEEVE CAN BE DISPLACED RADIALLY FROM SAID HOUSING, FLUID CONDUITS THROUGH SAID HOUSING, GRAVITY-SENSITIVE MEANS SUPPORTED FROM SAID HOUSING FOR APPORTIONING DRILLING FLUID FLOWING THROUGH SAID DRILL PIPE TO SAID FLUID CONDUITS IN RELATION TO THE ATTITUDE OF SAID HOUSING, AND PRESSURE-RESPONSIVE MEANS CARRIED BY SAID HOUSING ACTING SUBSTANTIALLY RADIALLY TO SAID HOUSING FOR APPLYING OUTWARD PRESSURE ON SAID SLEEVE PROPORTIONAL TO FLUID PRESSURE IN SAID CONDUIT TO FORCE SAID HOUSING OUTWARD IN RESPONSE TO THE POSITION OF SAID GRAVITY-SENSITIVE MEANS.