CA1252081A - Underground, fluid driven directional drilling device - Google Patents
Underground, fluid driven directional drilling deviceInfo
- Publication number
- CA1252081A CA1252081A CA000513725A CA513725A CA1252081A CA 1252081 A CA1252081 A CA 1252081A CA 000513725 A CA000513725 A CA 000513725A CA 513725 A CA513725 A CA 513725A CA 1252081 A CA1252081 A CA 1252081A
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- drill string
- piston
- chamber
- sleeve
- pipe
- Prior art date
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Abstract
ABSTRACT
An articulated non-rotating drill string has an articulated head which incorporates a first stage impeller and a second stage impeller connected together by a universal joint to allow articulation, along with a piston arrangement covered by a shroud associated with one of the articulating elements, the pistons being adapted to push differentially against the shroud and articulate the drilling head. Individual elongate sections of the drill string are also articulated together in a non-rotating and fluid-tight manner, using partial spherical cavities and complementary inserts.
Compression springs adjacent each articulating joint are arranged so as to urge the articulated portions into alignment. The drill string also incorporates a centering mechanism involving three sets of articulated arms, utilizing the internal fluid pressure in the drill string to urge the three articulated arm sets outwardly and center the drill string.
An articulated non-rotating drill string has an articulated head which incorporates a first stage impeller and a second stage impeller connected together by a universal joint to allow articulation, along with a piston arrangement covered by a shroud associated with one of the articulating elements, the pistons being adapted to push differentially against the shroud and articulate the drilling head. Individual elongate sections of the drill string are also articulated together in a non-rotating and fluid-tight manner, using partial spherical cavities and complementary inserts.
Compression springs adjacent each articulating joint are arranged so as to urge the articulated portions into alignment. The drill string also incorporates a centering mechanism involving three sets of articulated arms, utilizing the internal fluid pressure in the drill string to urge the three articulated arm sets outwardly and center the drill string.
Description
TTR22 ~25~081 UNDERGROUND, FLUID DRIVEN DIRECTIONAL DRILLING DEVICE
This invention relates to underground fluid driven directional drilling devices particularly adapted for drilling wells and mining oil, but not limited thereto.
GENERAL DESCRIPTION OF THIS INVENTION
.
There is a need in the well-drilling and oil mining industry for a flexible, non-rotating drill string which is capable of drilling curvilinear bore holes and following the curved configuration as it proceeds. The kind of drill string contemplated herein is one made up of concatenated sections of hollow drill pipe capable of holding a working fluid at high pressure, and of course the articulated joints between sections of the pipe must be capable of withstanding and containing the fluid pressure. A further aspect of this invention is the provision of a~ drilling head which is itself articulating, the angulation of which can be controlled either by adjusting the internal fluid pressure in the drill string, or by controlling separate fluid pressures in separate conduits associated with the drill string.
Yet another aspect of this invention is the provision of a centering means adjacent the articulating head, having the capability of holding the drill string at a centered location in a bore hole.
More particularly, this invention provides an articulated drilling head for use with a non-rotating drill string having a central passage for carrying working fluid under pressure to the drilling head, and having an axis. The drilling head comprises first means defining a first chamber adjacent the end of the drill string, and a first stage impeller in that chamber, the impeller being freely rotatable about the axis of the drill string. Second means is articulably connected to said first means for swinging movement in at least one plane containing the drill string axis, and the second means defines a second chamber. A second stage impeller is located in the second chamber, connected through a universal joint to the first stage impeller. A
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connector means is connected to rotate with the second stage impeller, so that a drilling bit can be attached to turn with the second stage impeller.
This invention further provides, in combination, a non-rotary drill string including a pipe member having a central passage for carrying fluid under pressure, and at least three circumferentially distributed first arms, each mounted at one end to the pipe member for swinginy movement in a different plane containing the axis of the pipe member. For each first arm there is a second arm pivotally connected at one end to the other end of its respective first arm, such that each second arm moves in the same plane as its respective first arm. A slidable sleeve is mounted on the pipe member, and the other ends of the second arms are pivotally connected to the sleeve. The sleeve has a surface in part defining a chamber to which fluid under pressure is admitted from the pipe member. The fluid seeks to move the sleeve in the direction of the first arms, so that each articulated combination of first and second arms tends to geniculate and urge their common pivot location radially outwardly with respect to the pipe member, thus centering the pipe member when it is located in a bore hole.
This invention further provides a resilient flexible joint between two longitudinally adjacent pipe sections of a non-rotating drill string. The pipe sections are hollow. One section has first means defining a curvilinear cavity at the joint, the cavity being a surface of revolution about an axis transverse to the drill string. The other section has second means defining an insert complementary with the cavity and received snugly but slidably therein. Annular compression spring means is located around the drill string adjacent the location of the flexible joint. The two pipe sections are secured to respective annular support portions on either side longitudinally of the spring means, so that angulation of one pipe section with respect to the other causes the support portions to ~2S~
compress the spring means at one circumferential region and to relax the spring means at a diametrally opposed region thereof, so that the spring means will resist such angulation and tend to restore the pipe sections to alignment.
GENERAL DESCRIPTION OF THE DRA INGS
Embodiments of the various aspects of this invention are illustrated in the accompanying drawings, in which like numerals denote like parts throughout the several views, and in which:
Figure l is a longitudinal sectional view, somewhat schematically drawn, showing one context of use for the drill string of this invention;
Figure 2 is an axial sectional view of a drill string incorporating facets of this invention in the upper half, and an elevational view thereof in the lower half;
Figure 3 is a cross-sectional view taken at the line 3-3 in Figure 2;
Figure 4 is a cross-sectional view taken at the line ~-4 in Figure 2;
Figure 5 is a cross-sectional view taken at the line 4-4 in Figure 2;
Figure 6 is an axial sectional view of a variation of the articulating drill string head;
Figures 7 and 8 show two embodiments of the mechanism utilized to angulate the drill string head;
and Figure 9 is an alternative embodiment of one portion of the drill string head.
DETAILED DESCRIPTION OF_THE DRAWINGS
Attention is first directed to Figure l, which shows a mine shaft lO extending down from the ground surface 12 to a drilling chamber 13. A drill string 14 extends downwardly along the mine shaft lO, and undergoes a curvilinear change of direction at 16, so that the lower portion of the drill string extends horizontally. A guide means 18 is provided to cause the drill string to undergo curvature. Above the ground ~s~
level 12, a support ~rame 20 is constructed, supporting a motor and associated gearing 22 which is adapted to cause a coupling 24 to reciprocate vertically, in order to cause downward incremental movement of the drill string 14. The coupling 24 is connected to a hollow pipe 26 ~orming part of a hydraulic cylinder arrangement, incorporating an upper cylinder 28 adapted to feed drilling fluid under pressure downwardly through the coupling 24 and into the hollow drill string 14.
Pressurized drilling fluid is supplied to the cylinder 28 along a line 30 from a pump 32 which draws the fluid from a tank 34. Upstream of the tank 34 is a filtration system 36.
When drilling in order to recover oil from tar sands and the like, the working 41uid is usually water at high temperature, or steam, and as the working fluid passes through the boring head 38 at the downstream end of the drill string 14 (seen at lower right in Figure l), it causes rotation of the drilling bit. The exiting drilling fluid then passes by return flow along the bore that has been drilled, outside of the drill string, and descends along conduit 40 into a sump 42 from which it ls pumped or drawn by a pump 44. If the liquid in the sump 42 contains hydrocarbons, it is pumped through line 46 to an oil recovery plant 48, from which purified water is fed through line 50 and back to the filter 36.
Otherwise, in the case where the return fluid has no significant hydrocarbon content, it is fed directly through the pipe 52 and back to the filter 36, from where it passes into the tank 34.
~ nother component within the drilling chamber 13 is a hydraulic ram 54 having a cylinder 56 fixed in place, and a horizontally slidable piston 58. The forward or rightward end of the piston 58 is secured to a coupling member 60, which is adapted to clamp the drill string 14 at a leftward location, and then urge the drill string rightwardly as drilling proceeds. By using this arrangement, the entire drilling force does not have to be exerted downwardly from above the ground level 12.
~L~52081 As can be seen, the drill string 14 incorporates a plurality of concatenated pipe sections 62, which of course must be connected together in a fluid-tight manner capable of containing the pressure of the fluid, 5 while still allowing the drill string to bend through a given curvature. This requires flexible but sealed joints between adjacent pipe sections.
As stated earlier, this invention is directed to the provision of a drill str:ing which is a non-rotating string. The rotation of the bit takes place at the lower end of the drill string, where the fluid pressure is converted to the work of rotary drilling.
Attention is now directed to Figure 2, which shows at the leftward end a drilling head 100. The head 100 incorporates a pipe 102 which is threadably engaged at the right with a sleeve 104, and which is threadably engaged at the left with a further sleeve 106. The pipe 102 and the sleeve 106 together define a continuous internal cylindrical surface 108 against which is snugly received a cylindrical low-friction liner 110. Mounted for free rotation within the liner 110 is a first stage impeller 112 which incorporates a hub 114 and a plurality of helical blades 116. The first stage impeller 112 is not constrained axially, and is capable of limited axial movement within the liner 108, the limitation being a result of the connection between the first stage impeller 112 and a second stage impeller 118 which includes a hub 120 and a plurality of helical blades 122. The second stage impeller 118 is fixed to a housing 124, which has a cylindrical outer surface surrounded by a thin, low-friction collar 126. The collar 126 is separated centrally to allow for the projection of an annular flange 128 which is integral with the housing 124. The flange 128 projects outwardly into a chamber 130 defined within a forward sleeve 132, the sleeve 132 having an inner wall 134 and an outer wall 136, the two walls 134 and 136 being joined by an annular wall 138. At the rightward or upstream end of the sleeve 132, there is a threaded connection with a ~2~ii2t~
member 140, which defines at 142 a spherical cavity which is of limited circumferential extent. An identical such cavity is found at the diametrally opposed location (not visible in Figure 2). The center of curvature of the cavity 142 is shown at 144. The member 140 is threadably connected to a further member 1~6, which defines another spherical cavity 148 of limited circumferential extent, and also defines a diametrally opposed identical such chamber. It will be seen that the cavity 148 has the same ce~ter of curvature 144 as the cavity 142, but has a greater radius.
The member 146 defines a shroud 150 which completely surrounds the sleeve 106, but is spaced therefrom. As can be seen, there is a gap 152 between the rightward inner terminal portion of the shroud 150 and the sleeve 106. The purpose for the gap 152 will become apparent in the description that follows.
The first stage impeller 112 is connected to the second stage impeller 118 by a universal coupling 154 of standard construction. This connection ties the two impellers together in an axial sense, but allows the one to articulate with respect to the other. The universal coupling 154 also requires the two impellers to rotate together.
Returning to the chamber 130, it will be seen that there is provided a further chamber 156, defined by the member 140, the chamber 156 being similar to the chamber 130, in that the member 140 has an inner wall 158 and an outer wall 160 defining the inner and outer limits of the chamber 156.
Within the leftward chamber 130 there is a spring means 162, preferably a plurality of conical washers, sometimes known as Belleville washers, which are in compression and urge rightwardly against a plurality of ball bearings 164, which in turn press rightwardly or in the upstream dixection against the flange 128.
Similarly in the rightward chamber 156 there is an e~uivalent spring means 166, which urges leftwardly '~2~
against ball bearings 168, which in turn press leftwardly or in the downstream direction against the other side of the flange 128. The arrangement just described thus provides a resilient retention mechanism for urging the flange 128 toward a position in which the forces on the left and on the right are in balance.
However, axial force rightwardly against the drilling head, shown at 170, can dispLace the second stage impeller 118 and the flange :L28 rightwardly, until the axial force on the head 170 :Ls releasedO In essence, the arrangement provides a shock-absorption for axial forces undergone by the head 170. It will be appreciated that, if the head 170 moves rightwardly with respect to the sleeve 132, then both of the impellers will move rightwardly the same distance.
Attention is now directed again to the sleeve 106, which is threadably engaged with the pipe 102. The sleeve 106 integrally defines, at its downstream or leftward end, a first spherical insert 172 which is received in the cavity 142, and a second spherical insert 174, which is received in the other spherical cavity 148. The sleeve 106 defines two identical such inserts at the diametrally opposed position, not visible in Figure 2.
It will thus be appreciated that limited articulating capability exists between the sleeve 106 and the combination of the member 140 and the member 146 which are threadably engaged with each other. It will now be understood why the gap 152 must be provided, namely to permit this articulation to take place. When articulation occurs, the direction of drilling is angulated slightly with respect to the remainder of the adjacent string, and a change in direction can be ` initiated.
The device which accomplishes the change in direction in a positive manner is shown at 176, and will be described in greater detail with reference to another figure.
~252~8~L
Attention is now directed to the pipe 102, which provides at its leftward or downstream end a mounting ring 180 to which three downstream arms 182 are pivotally connected for swinging movement in three different planes, each plane containing the axis of the pipe 102. In other words, each of the downstream arms 182 is capable of swinging outwardly away from the axis of the pipe 102, or alternatively toward the axis. In the embodiment shown, the three downstream arms are distributed at 120 intervals around the circumference of the pipe 10~. For each downstream arm 182 there is an upstream arm 184 which is pivotally connected at one end to the upstream end of the respective downstream arm 182, in such a way that each of the upstream arms moves in the same plane as its respective first arm. Thus, the movement of each upstream arm 184 is constrained to be within a plane which contains the axis of the pipe 102. The numeral 186 defines the pi~ot axis between each pair of upstream and downstream arms. A slidable sleeve 188 is mounted on the pipe 102, and also on the sleeve 104. It will be seen that the outer diameter of the sleeve 104 at the location in question is slightly greater than the outer diameter of the pipe 102, and the reason for this will become apparent presently. Thus, the sleeve 188 has an equivalent outward step, to accommodate the difference in diameters. The sleeve 188 has at the rightward end a mounting means 190 such that it can be pivotally connected to the rightward or upstxeam end of each of'the upstream arms. The pivot axis in question is shown at 192.
It will be appreciated that the sleeve 188 is shown in its furthest rightward or furthest upstream position in Figure 2, this being determined by the step mentioned earlier. It can also be visualized that, as the sleeve 188 mo~es leftwardly, each pair of upstream and downstream arms geniculate to urge their common pivot location 186 radially outwardly with respect to the pipe 102, thus centering the pipe 102 when it is located in any drilled shaft or bore hole.
:~2S~08~L
The leftward or downstream movement of the sleeve 188 is caused by the admission of pressurized fluid from inside the pipe 102, through a radial bore 196, and into a chamber defined in part by a wall of the sleeve 188 extending between the smaller diameter portion and the larger diameter portion. It will thus be understood that the pressure of the working fluid within the pipe 102 seeks continuously to move the sleeve member 188 to the left, thus continuously urging the common pivot locations 186 of the pairs of arms outwardly, thus continuously seeking to center the pipe 102.
The ring 180 is located adjacent the rightward or upstream end of the shroud 150, as can be seen in Figure
This invention relates to underground fluid driven directional drilling devices particularly adapted for drilling wells and mining oil, but not limited thereto.
GENERAL DESCRIPTION OF THIS INVENTION
.
There is a need in the well-drilling and oil mining industry for a flexible, non-rotating drill string which is capable of drilling curvilinear bore holes and following the curved configuration as it proceeds. The kind of drill string contemplated herein is one made up of concatenated sections of hollow drill pipe capable of holding a working fluid at high pressure, and of course the articulated joints between sections of the pipe must be capable of withstanding and containing the fluid pressure. A further aspect of this invention is the provision of a~ drilling head which is itself articulating, the angulation of which can be controlled either by adjusting the internal fluid pressure in the drill string, or by controlling separate fluid pressures in separate conduits associated with the drill string.
Yet another aspect of this invention is the provision of a centering means adjacent the articulating head, having the capability of holding the drill string at a centered location in a bore hole.
More particularly, this invention provides an articulated drilling head for use with a non-rotating drill string having a central passage for carrying working fluid under pressure to the drilling head, and having an axis. The drilling head comprises first means defining a first chamber adjacent the end of the drill string, and a first stage impeller in that chamber, the impeller being freely rotatable about the axis of the drill string. Second means is articulably connected to said first means for swinging movement in at least one plane containing the drill string axis, and the second means defines a second chamber. A second stage impeller is located in the second chamber, connected through a universal joint to the first stage impeller. A
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connector means is connected to rotate with the second stage impeller, so that a drilling bit can be attached to turn with the second stage impeller.
This invention further provides, in combination, a non-rotary drill string including a pipe member having a central passage for carrying fluid under pressure, and at least three circumferentially distributed first arms, each mounted at one end to the pipe member for swinginy movement in a different plane containing the axis of the pipe member. For each first arm there is a second arm pivotally connected at one end to the other end of its respective first arm, such that each second arm moves in the same plane as its respective first arm. A slidable sleeve is mounted on the pipe member, and the other ends of the second arms are pivotally connected to the sleeve. The sleeve has a surface in part defining a chamber to which fluid under pressure is admitted from the pipe member. The fluid seeks to move the sleeve in the direction of the first arms, so that each articulated combination of first and second arms tends to geniculate and urge their common pivot location radially outwardly with respect to the pipe member, thus centering the pipe member when it is located in a bore hole.
This invention further provides a resilient flexible joint between two longitudinally adjacent pipe sections of a non-rotating drill string. The pipe sections are hollow. One section has first means defining a curvilinear cavity at the joint, the cavity being a surface of revolution about an axis transverse to the drill string. The other section has second means defining an insert complementary with the cavity and received snugly but slidably therein. Annular compression spring means is located around the drill string adjacent the location of the flexible joint. The two pipe sections are secured to respective annular support portions on either side longitudinally of the spring means, so that angulation of one pipe section with respect to the other causes the support portions to ~2S~
compress the spring means at one circumferential region and to relax the spring means at a diametrally opposed region thereof, so that the spring means will resist such angulation and tend to restore the pipe sections to alignment.
GENERAL DESCRIPTION OF THE DRA INGS
Embodiments of the various aspects of this invention are illustrated in the accompanying drawings, in which like numerals denote like parts throughout the several views, and in which:
Figure l is a longitudinal sectional view, somewhat schematically drawn, showing one context of use for the drill string of this invention;
Figure 2 is an axial sectional view of a drill string incorporating facets of this invention in the upper half, and an elevational view thereof in the lower half;
Figure 3 is a cross-sectional view taken at the line 3-3 in Figure 2;
Figure 4 is a cross-sectional view taken at the line ~-4 in Figure 2;
Figure 5 is a cross-sectional view taken at the line 4-4 in Figure 2;
Figure 6 is an axial sectional view of a variation of the articulating drill string head;
Figures 7 and 8 show two embodiments of the mechanism utilized to angulate the drill string head;
and Figure 9 is an alternative embodiment of one portion of the drill string head.
DETAILED DESCRIPTION OF_THE DRAWINGS
Attention is first directed to Figure l, which shows a mine shaft lO extending down from the ground surface 12 to a drilling chamber 13. A drill string 14 extends downwardly along the mine shaft lO, and undergoes a curvilinear change of direction at 16, so that the lower portion of the drill string extends horizontally. A guide means 18 is provided to cause the drill string to undergo curvature. Above the ground ~s~
level 12, a support ~rame 20 is constructed, supporting a motor and associated gearing 22 which is adapted to cause a coupling 24 to reciprocate vertically, in order to cause downward incremental movement of the drill string 14. The coupling 24 is connected to a hollow pipe 26 ~orming part of a hydraulic cylinder arrangement, incorporating an upper cylinder 28 adapted to feed drilling fluid under pressure downwardly through the coupling 24 and into the hollow drill string 14.
Pressurized drilling fluid is supplied to the cylinder 28 along a line 30 from a pump 32 which draws the fluid from a tank 34. Upstream of the tank 34 is a filtration system 36.
When drilling in order to recover oil from tar sands and the like, the working 41uid is usually water at high temperature, or steam, and as the working fluid passes through the boring head 38 at the downstream end of the drill string 14 (seen at lower right in Figure l), it causes rotation of the drilling bit. The exiting drilling fluid then passes by return flow along the bore that has been drilled, outside of the drill string, and descends along conduit 40 into a sump 42 from which it ls pumped or drawn by a pump 44. If the liquid in the sump 42 contains hydrocarbons, it is pumped through line 46 to an oil recovery plant 48, from which purified water is fed through line 50 and back to the filter 36.
Otherwise, in the case where the return fluid has no significant hydrocarbon content, it is fed directly through the pipe 52 and back to the filter 36, from where it passes into the tank 34.
~ nother component within the drilling chamber 13 is a hydraulic ram 54 having a cylinder 56 fixed in place, and a horizontally slidable piston 58. The forward or rightward end of the piston 58 is secured to a coupling member 60, which is adapted to clamp the drill string 14 at a leftward location, and then urge the drill string rightwardly as drilling proceeds. By using this arrangement, the entire drilling force does not have to be exerted downwardly from above the ground level 12.
~L~52081 As can be seen, the drill string 14 incorporates a plurality of concatenated pipe sections 62, which of course must be connected together in a fluid-tight manner capable of containing the pressure of the fluid, 5 while still allowing the drill string to bend through a given curvature. This requires flexible but sealed joints between adjacent pipe sections.
As stated earlier, this invention is directed to the provision of a drill str:ing which is a non-rotating string. The rotation of the bit takes place at the lower end of the drill string, where the fluid pressure is converted to the work of rotary drilling.
Attention is now directed to Figure 2, which shows at the leftward end a drilling head 100. The head 100 incorporates a pipe 102 which is threadably engaged at the right with a sleeve 104, and which is threadably engaged at the left with a further sleeve 106. The pipe 102 and the sleeve 106 together define a continuous internal cylindrical surface 108 against which is snugly received a cylindrical low-friction liner 110. Mounted for free rotation within the liner 110 is a first stage impeller 112 which incorporates a hub 114 and a plurality of helical blades 116. The first stage impeller 112 is not constrained axially, and is capable of limited axial movement within the liner 108, the limitation being a result of the connection between the first stage impeller 112 and a second stage impeller 118 which includes a hub 120 and a plurality of helical blades 122. The second stage impeller 118 is fixed to a housing 124, which has a cylindrical outer surface surrounded by a thin, low-friction collar 126. The collar 126 is separated centrally to allow for the projection of an annular flange 128 which is integral with the housing 124. The flange 128 projects outwardly into a chamber 130 defined within a forward sleeve 132, the sleeve 132 having an inner wall 134 and an outer wall 136, the two walls 134 and 136 being joined by an annular wall 138. At the rightward or upstream end of the sleeve 132, there is a threaded connection with a ~2~ii2t~
member 140, which defines at 142 a spherical cavity which is of limited circumferential extent. An identical such cavity is found at the diametrally opposed location (not visible in Figure 2). The center of curvature of the cavity 142 is shown at 144. The member 140 is threadably connected to a further member 1~6, which defines another spherical cavity 148 of limited circumferential extent, and also defines a diametrally opposed identical such chamber. It will be seen that the cavity 148 has the same ce~ter of curvature 144 as the cavity 142, but has a greater radius.
The member 146 defines a shroud 150 which completely surrounds the sleeve 106, but is spaced therefrom. As can be seen, there is a gap 152 between the rightward inner terminal portion of the shroud 150 and the sleeve 106. The purpose for the gap 152 will become apparent in the description that follows.
The first stage impeller 112 is connected to the second stage impeller 118 by a universal coupling 154 of standard construction. This connection ties the two impellers together in an axial sense, but allows the one to articulate with respect to the other. The universal coupling 154 also requires the two impellers to rotate together.
Returning to the chamber 130, it will be seen that there is provided a further chamber 156, defined by the member 140, the chamber 156 being similar to the chamber 130, in that the member 140 has an inner wall 158 and an outer wall 160 defining the inner and outer limits of the chamber 156.
Within the leftward chamber 130 there is a spring means 162, preferably a plurality of conical washers, sometimes known as Belleville washers, which are in compression and urge rightwardly against a plurality of ball bearings 164, which in turn press rightwardly or in the upstream dixection against the flange 128.
Similarly in the rightward chamber 156 there is an e~uivalent spring means 166, which urges leftwardly '~2~
against ball bearings 168, which in turn press leftwardly or in the downstream direction against the other side of the flange 128. The arrangement just described thus provides a resilient retention mechanism for urging the flange 128 toward a position in which the forces on the left and on the right are in balance.
However, axial force rightwardly against the drilling head, shown at 170, can dispLace the second stage impeller 118 and the flange :L28 rightwardly, until the axial force on the head 170 :Ls releasedO In essence, the arrangement provides a shock-absorption for axial forces undergone by the head 170. It will be appreciated that, if the head 170 moves rightwardly with respect to the sleeve 132, then both of the impellers will move rightwardly the same distance.
Attention is now directed again to the sleeve 106, which is threadably engaged with the pipe 102. The sleeve 106 integrally defines, at its downstream or leftward end, a first spherical insert 172 which is received in the cavity 142, and a second spherical insert 174, which is received in the other spherical cavity 148. The sleeve 106 defines two identical such inserts at the diametrally opposed position, not visible in Figure 2.
It will thus be appreciated that limited articulating capability exists between the sleeve 106 and the combination of the member 140 and the member 146 which are threadably engaged with each other. It will now be understood why the gap 152 must be provided, namely to permit this articulation to take place. When articulation occurs, the direction of drilling is angulated slightly with respect to the remainder of the adjacent string, and a change in direction can be ` initiated.
The device which accomplishes the change in direction in a positive manner is shown at 176, and will be described in greater detail with reference to another figure.
~252~8~L
Attention is now directed to the pipe 102, which provides at its leftward or downstream end a mounting ring 180 to which three downstream arms 182 are pivotally connected for swinging movement in three different planes, each plane containing the axis of the pipe 102. In other words, each of the downstream arms 182 is capable of swinging outwardly away from the axis of the pipe 102, or alternatively toward the axis. In the embodiment shown, the three downstream arms are distributed at 120 intervals around the circumference of the pipe 10~. For each downstream arm 182 there is an upstream arm 184 which is pivotally connected at one end to the upstream end of the respective downstream arm 182, in such a way that each of the upstream arms moves in the same plane as its respective first arm. Thus, the movement of each upstream arm 184 is constrained to be within a plane which contains the axis of the pipe 102. The numeral 186 defines the pi~ot axis between each pair of upstream and downstream arms. A slidable sleeve 188 is mounted on the pipe 102, and also on the sleeve 104. It will be seen that the outer diameter of the sleeve 104 at the location in question is slightly greater than the outer diameter of the pipe 102, and the reason for this will become apparent presently. Thus, the sleeve 188 has an equivalent outward step, to accommodate the difference in diameters. The sleeve 188 has at the rightward end a mounting means 190 such that it can be pivotally connected to the rightward or upstxeam end of each of'the upstream arms. The pivot axis in question is shown at 192.
It will be appreciated that the sleeve 188 is shown in its furthest rightward or furthest upstream position in Figure 2, this being determined by the step mentioned earlier. It can also be visualized that, as the sleeve 188 mo~es leftwardly, each pair of upstream and downstream arms geniculate to urge their common pivot location 186 radially outwardly with respect to the pipe 102, thus centering the pipe 102 when it is located in any drilled shaft or bore hole.
:~2S~08~L
The leftward or downstream movement of the sleeve 188 is caused by the admission of pressurized fluid from inside the pipe 102, through a radial bore 196, and into a chamber defined in part by a wall of the sleeve 188 extending between the smaller diameter portion and the larger diameter portion. It will thus be understood that the pressure of the working fluid within the pipe 102 seeks continuously to move the sleeve member 188 to the left, thus continuously urging the common pivot locations 186 of the pairs of arms outwardly, thus continuously seeking to center the pipe 102.
The ring 180 is located adjacent the rightward or upstream end of the shroud 150, as can be seen in Figure
2. Between these two is located an annular, flexible sealing element 200, for the purpose of keeping working fluid which is passing outwardly alongside the pipe 102 from entering the space within the shroud 150 and possibly interfering with the operation of the control of the angulation for the head.
Turning attention now to sleeve 104, it will be seen that the same is threadably connected to a collar 202, and that the sleeve 10~ and collar 202 respectively define a first spherical cavity 204 of limited circumferential extent, and a second spherical caviiy 206 also of limited circumferential extent. These two members define identical such cavities at the diametrally opposed location, but these are not seen in Figure 2. Receivable in the cavities 204 and 206 are spherical inserts 208 and 210, both being integral with a sleeve 212 which is threadably engaged with a pipe section 214 of the drill string. The pipe section 214 is of substantial length compared with the other portions described previously, and constitutes a primary or main section of the drill string. Its length will be determined by the desired radius of curvature for the drill string as it angulates between a vertical orientation and a horizontal orientation.
Between the insert 210 and the sleeve 104 there is defined a chamber in which a sealing member 216 is ~252(~
provided. A similar sealing member is provided in the corresponding chamber at the diametrally opposed location.
The pipe section 214 carries at its downstream end S a ring 218, which is spaced axially from the rightward end of the collar 202. In the gap between these two there is provided a plurality of conical washers 220, which are constantly in compression and thus seek to push the ring 218 and the collar 202 away from each other in the axial direction. It will thus be appreciated that, as the sleeve 104 angulates with respect to the pipe section 214, the conical springs 220 will be compressed at one circumferential location, and relaxed at the opposed location. This means that such articulation will be resisted by the springs, which will seek constantly to maintain the pipe section 214 and the sleeve 104 in approximate axial alignment. A protective plastic cap 222 is provided to keep extraneous material away from the conical springs 220. At the rightward end in Figure 2, an identical such articulated joint is shown between the pipe section 214 and a further pipe section 224. The two joints are identical in terms of the main functioning of the elements, although the dimensions are slightly different. The joint shown at the right in Figure 2 is between two similar pipe sections, whereas the joint shown at the left is between the furthest downstream pipe section and the upstream portions of the head 100.
The limited circumferential extent of the spherical connection at the right in Figure 2 is visible in Figure 5. In Figure 5, a spherical insert 226 is provided at one location on a sleeve 228, and an identical such insert 230 is provided at the diametrally opposed location. The rightward or upstream end of the pipe 214 provides spherical cavities complementary to the inserts 226 and 230. A first protective collar 232 is threaded on the pipe 214 and defines a spherical cavity for a second insert 234 provided on the sleeve 228. Both the sleeve 228 and the next upstream pipe section 224 are ~S;~C~8~
threaded to a collar 236, as can be seen at the right in Figure 2. ~etween the collars 232 and 236 are located a plurality of conical springs 240 similar in function to the springs 220. A cap 242 keeps the springs 240 free of contamination.
Attention is now directed to Figure 6, which shows a slightly different embodiment for the drilling head.
In Figure 6, the first stage impeller 250 is connected by a universal joint 252 to a second stage impeller 254.
The second stage impeller 254 is secured to a rotary sleeve 256 having an external thread 258 at its downstream end, for receiving the drilling bit (not seen).
In the embodiment shown in Figure 6, the spherical joint between the sleeve 260 and the member 262 is equipped with ring seal 264, and with sliding seals 266.
Otherwise, the basic stru~ture is similar to that described in connection with Figure 2.
Attention is now directed to Figures 2, 6, 7 and 8, for a description of the device which accomplishes the positive angulation of the downstream portion of the drilling head with respect to the upstream portion thereof.
In Figure 7, the sleeve 106 is drawn in section, and it can be seen that a first cylinder 262 is mounted in the wall of the sleeve and projects outwardly therefrom. The mounting can be done by way of a threaded connection. The cylinder 262 defines an inward shoulder 264 at the inward end, and a further shoulder 266 at the outward end. Slidably mounted within the cylinder 262 is a further cylinder 270 having a first outwardly projecting annular portion 272 which slides snugly against the inner surface of the cylinder 262.
The cylinder 270 has an outer surface 274 which slides snugly against the inner surface 276 at the top of the cylinder 262. There is thus defined an annular chamber 280, to which pressurized fluid can be admitted through a port 282 in the side of the first cylinder 262.
~25;~
The cylinder 270 is configurèd at the top similarly to the cylinder 276, and thus defines an inwardly projecting annular portion 284 which Eurther defines an upper shoulder 286. The inner cylinder 270 also defines a lower shoulder 288.
A piston 290 is slidably mounted within the inner cylinder 270, the piston having a cylindrical upper portion which smoothly slides within the upper part of the cylinder 270, and ~urthe:r has an outward annular flange 292 which slides against the larger-diameter inner bore of the inner cylinder 270. There is thus defined a further annular chamber 296 to which fluid can be admitted through a port 298.
Mounted adjacent the cylinder 262 is a pressure-sensitive valve 302, the valve 302 defining an internal chamber 304 which is connected along a bore 306 to the fluid pressure inside the sleeve 106. As can be seen, the bore 306 communicates with a frusto-conical passageway 308 at the bottom of the valve 302 which opens into the chamber 304. Stopping the frusto-conical passageway 308 is a frusto-conical stopper 310 which is connected to a pin 312 having a conical point 314 adapted to be inserted into a similarly shaped opening 316 at the top of the valve 302, to stop the same~ A
compression coil spring 31B urges the combination of the pin 312 and the stopper 310 downwardly to block the frusto-conical passageway 308, and to open the opening 316. Fluid conduits are connected between a port 320 in the side of the valve 302 and both the port 282 and the
Turning attention now to sleeve 104, it will be seen that the same is threadably connected to a collar 202, and that the sleeve 10~ and collar 202 respectively define a first spherical cavity 204 of limited circumferential extent, and a second spherical caviiy 206 also of limited circumferential extent. These two members define identical such cavities at the diametrally opposed location, but these are not seen in Figure 2. Receivable in the cavities 204 and 206 are spherical inserts 208 and 210, both being integral with a sleeve 212 which is threadably engaged with a pipe section 214 of the drill string. The pipe section 214 is of substantial length compared with the other portions described previously, and constitutes a primary or main section of the drill string. Its length will be determined by the desired radius of curvature for the drill string as it angulates between a vertical orientation and a horizontal orientation.
Between the insert 210 and the sleeve 104 there is defined a chamber in which a sealing member 216 is ~252(~
provided. A similar sealing member is provided in the corresponding chamber at the diametrally opposed location.
The pipe section 214 carries at its downstream end S a ring 218, which is spaced axially from the rightward end of the collar 202. In the gap between these two there is provided a plurality of conical washers 220, which are constantly in compression and thus seek to push the ring 218 and the collar 202 away from each other in the axial direction. It will thus be appreciated that, as the sleeve 104 angulates with respect to the pipe section 214, the conical springs 220 will be compressed at one circumferential location, and relaxed at the opposed location. This means that such articulation will be resisted by the springs, which will seek constantly to maintain the pipe section 214 and the sleeve 104 in approximate axial alignment. A protective plastic cap 222 is provided to keep extraneous material away from the conical springs 220. At the rightward end in Figure 2, an identical such articulated joint is shown between the pipe section 214 and a further pipe section 224. The two joints are identical in terms of the main functioning of the elements, although the dimensions are slightly different. The joint shown at the right in Figure 2 is between two similar pipe sections, whereas the joint shown at the left is between the furthest downstream pipe section and the upstream portions of the head 100.
The limited circumferential extent of the spherical connection at the right in Figure 2 is visible in Figure 5. In Figure 5, a spherical insert 226 is provided at one location on a sleeve 228, and an identical such insert 230 is provided at the diametrally opposed location. The rightward or upstream end of the pipe 214 provides spherical cavities complementary to the inserts 226 and 230. A first protective collar 232 is threaded on the pipe 214 and defines a spherical cavity for a second insert 234 provided on the sleeve 228. Both the sleeve 228 and the next upstream pipe section 224 are ~S;~C~8~
threaded to a collar 236, as can be seen at the right in Figure 2. ~etween the collars 232 and 236 are located a plurality of conical springs 240 similar in function to the springs 220. A cap 242 keeps the springs 240 free of contamination.
Attention is now directed to Figure 6, which shows a slightly different embodiment for the drilling head.
In Figure 6, the first stage impeller 250 is connected by a universal joint 252 to a second stage impeller 254.
The second stage impeller 254 is secured to a rotary sleeve 256 having an external thread 258 at its downstream end, for receiving the drilling bit (not seen).
In the embodiment shown in Figure 6, the spherical joint between the sleeve 260 and the member 262 is equipped with ring seal 264, and with sliding seals 266.
Otherwise, the basic stru~ture is similar to that described in connection with Figure 2.
Attention is now directed to Figures 2, 6, 7 and 8, for a description of the device which accomplishes the positive angulation of the downstream portion of the drilling head with respect to the upstream portion thereof.
In Figure 7, the sleeve 106 is drawn in section, and it can be seen that a first cylinder 262 is mounted in the wall of the sleeve and projects outwardly therefrom. The mounting can be done by way of a threaded connection. The cylinder 262 defines an inward shoulder 264 at the inward end, and a further shoulder 266 at the outward end. Slidably mounted within the cylinder 262 is a further cylinder 270 having a first outwardly projecting annular portion 272 which slides snugly against the inner surface of the cylinder 262.
The cylinder 270 has an outer surface 274 which slides snugly against the inner surface 276 at the top of the cylinder 262. There is thus defined an annular chamber 280, to which pressurized fluid can be admitted through a port 282 in the side of the first cylinder 262.
~25;~
The cylinder 270 is configurèd at the top similarly to the cylinder 276, and thus defines an inwardly projecting annular portion 284 which Eurther defines an upper shoulder 286. The inner cylinder 270 also defines a lower shoulder 288.
A piston 290 is slidably mounted within the inner cylinder 270, the piston having a cylindrical upper portion which smoothly slides within the upper part of the cylinder 270, and ~urthe:r has an outward annular flange 292 which slides against the larger-diameter inner bore of the inner cylinder 270. There is thus defined a further annular chamber 296 to which fluid can be admitted through a port 298.
Mounted adjacent the cylinder 262 is a pressure-sensitive valve 302, the valve 302 defining an internal chamber 304 which is connected along a bore 306 to the fluid pressure inside the sleeve 106. As can be seen, the bore 306 communicates with a frusto-conical passageway 308 at the bottom of the valve 302 which opens into the chamber 304. Stopping the frusto-conical passageway 308 is a frusto-conical stopper 310 which is connected to a pin 312 having a conical point 314 adapted to be inserted into a similarly shaped opening 316 at the top of the valve 302, to stop the same~ A
compression coil spring 31B urges the combination of the pin 312 and the stopper 310 downwardly to block the frusto-conical passageway 308, and to open the opening 316. Fluid conduits are connected between a port 320 in the side of the valve 302 and both the port 282 and the
3~ port 298 in the cylinder 262 and the cylinder 270-respectively.
In order to activate the piston 290, the fluid pressure inside the sleeve 106 (i.e. inside the entire drill string) is increased, to the point where it will lift the stopper 310 upwardly out of the frusto-conical passageway 308, thus admitting pressurized fluid to the chamber 304, thus in turn admitting pressurized fluid to the annular chambers 280 and 296.
S~O~l It must be understood that, normally, when the valve 302 is closed, both the cylinder 270 and the piston 290 are pushed to the outermost position by fluid pressure within the sleeve 106, which directly contacts the underside of both of these elements. However, when the fluid pressure passes through the valve 302 and into the chambers 280 and 296, the outward pressure on the piston 290 is relaxed or counterbalanced, which means that the piston does not push outwardly with the same degree of force.
By making the valve arrangement for only one of the pistons and not the other, it will be understood that the non-valved piston will always push radially outwardly with maximum force depending upon the pressure of the fluid within the sleeve 106, but that the force with which the valved piston presses outwardly is controllable, precisely by controlling the fluid pressure within the sleeve 106. When the valve 302 trips, thus allowing fluid pressure to be admitted to the chambers 280 and 296, the continual outward pressure of the unvalved piston at the diametrally opposed location will cause the drilling head to articulate in such.a way that the shroud 150 moves toward the valved piston and away from the non-valved piston. This causes a bending of the direction of drilling, which is what is desired.
In Figure 8, the two cylinders 262 and 270 are shown together with the piston 290, as in Figure 7.
However, there is no valve equivalent to the valve 302.
Instead, a separate conduit carrying a separately controlled fluid such as hydraulic oil is directly connected through the port 282 thus being admitted into the annular chamber 296. From the chamber 296 it can pass freely through the port 350 into the annular chamber 280.
The arrangement of Figure 8 is suitable when three or more pistons are provided at equal intervals around the sleeve 106, to provide an embodiment in which the angular articulation of the drilling head is not limited :~2S~
to a single plane. It will be appreciated that the spherical cavities and inserts provided at the articulation point for the head could be replaced with a true spherical joint, al]owing articulation in any given direction. In such an embodiment, it would be preferable to provide three, or possibly more, pistons of the kind shown in Figure 8, and to run separate hydraulic conduits to each associated outer cylinder 262, so that the pistons can be separately controlled.
Attention is now directed to Figure 9, which corresponds to the portion at upper left in Figure 2.
The difference in Figure 9 i9 simply that the housing 124a is a composite of two members 400 and 402 threaded together, each of the members 400 and 402 providing an outwardly extending annular flange 404, 406, respectively, and each flange 404, 406 being located within a separate chamber defined by exterior members.
However, each chamber is similar in construction and function to the single chamber illustrated in Figure 2.
Within each chamber there are provided resilient conical washers in compression, along with ball bearings immediately adjacent each flange on either side. The construction will be self-evident from the figure, and does not need to be described in detail.
It will further be appreciated that the conical compression washers of the Belleville type could be replaced with other equivalent resilient members, for example resilient rings of various cross-sectional shapes.
While several embodiments of this invention have been illustrated in the accompanying drawings, it will be evident to those skilled in the art that changes and modifications may be made therein, without departing from the essence of this invention, as set forth in the appended claims.
In order to activate the piston 290, the fluid pressure inside the sleeve 106 (i.e. inside the entire drill string) is increased, to the point where it will lift the stopper 310 upwardly out of the frusto-conical passageway 308, thus admitting pressurized fluid to the chamber 304, thus in turn admitting pressurized fluid to the annular chambers 280 and 296.
S~O~l It must be understood that, normally, when the valve 302 is closed, both the cylinder 270 and the piston 290 are pushed to the outermost position by fluid pressure within the sleeve 106, which directly contacts the underside of both of these elements. However, when the fluid pressure passes through the valve 302 and into the chambers 280 and 296, the outward pressure on the piston 290 is relaxed or counterbalanced, which means that the piston does not push outwardly with the same degree of force.
By making the valve arrangement for only one of the pistons and not the other, it will be understood that the non-valved piston will always push radially outwardly with maximum force depending upon the pressure of the fluid within the sleeve 106, but that the force with which the valved piston presses outwardly is controllable, precisely by controlling the fluid pressure within the sleeve 106. When the valve 302 trips, thus allowing fluid pressure to be admitted to the chambers 280 and 296, the continual outward pressure of the unvalved piston at the diametrally opposed location will cause the drilling head to articulate in such.a way that the shroud 150 moves toward the valved piston and away from the non-valved piston. This causes a bending of the direction of drilling, which is what is desired.
In Figure 8, the two cylinders 262 and 270 are shown together with the piston 290, as in Figure 7.
However, there is no valve equivalent to the valve 302.
Instead, a separate conduit carrying a separately controlled fluid such as hydraulic oil is directly connected through the port 282 thus being admitted into the annular chamber 296. From the chamber 296 it can pass freely through the port 350 into the annular chamber 280.
The arrangement of Figure 8 is suitable when three or more pistons are provided at equal intervals around the sleeve 106, to provide an embodiment in which the angular articulation of the drilling head is not limited :~2S~
to a single plane. It will be appreciated that the spherical cavities and inserts provided at the articulation point for the head could be replaced with a true spherical joint, al]owing articulation in any given direction. In such an embodiment, it would be preferable to provide three, or possibly more, pistons of the kind shown in Figure 8, and to run separate hydraulic conduits to each associated outer cylinder 262, so that the pistons can be separately controlled.
Attention is now directed to Figure 9, which corresponds to the portion at upper left in Figure 2.
The difference in Figure 9 i9 simply that the housing 124a is a composite of two members 400 and 402 threaded together, each of the members 400 and 402 providing an outwardly extending annular flange 404, 406, respectively, and each flange 404, 406 being located within a separate chamber defined by exterior members.
However, each chamber is similar in construction and function to the single chamber illustrated in Figure 2.
Within each chamber there are provided resilient conical washers in compression, along with ball bearings immediately adjacent each flange on either side. The construction will be self-evident from the figure, and does not need to be described in detail.
It will further be appreciated that the conical compression washers of the Belleville type could be replaced with other equivalent resilient members, for example resilient rings of various cross-sectional shapes.
While several embodiments of this invention have been illustrated in the accompanying drawings, it will be evident to those skilled in the art that changes and modifications may be made therein, without departing from the essence of this invention, as set forth in the appended claims.
Claims (24)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An articulated drilling head for use with a non-rotating drill string having a central passage for carrying working fluid under pressure to the drilling head, and having an axis, the drilling head comprising:
first means defining a first chamber adjacent the end of the drill string, a first stage impeller in said chamber, the impeller being freely-rotatable about the axis of the drill string, second means articulably connected to said first means for swinging movement in at least one plane containing the drill string axis, a second chamber defined by said second means, a second stage impeller in said second chamber, connected through a universal joint to the first stage impeller, and connector means connected to rotate with said second stage impeller, whereby a drilling bit can be attached to turn with the second stage impeller.
first means defining a first chamber adjacent the end of the drill string, a first stage impeller in said chamber, the impeller being freely-rotatable about the axis of the drill string, second means articulably connected to said first means for swinging movement in at least one plane containing the drill string axis, a second chamber defined by said second means, a second stage impeller in said second chamber, connected through a universal joint to the first stage impeller, and connector means connected to rotate with said second stage impeller, whereby a drilling bit can be attached to turn with the second stage impeller.
2. The invention claimed in claim 1, in which the second stage impeller is connected firmly to a sleeve which defines said connector means, the sleeve having an outwardly projecting annular flange received within a substantially cylindrical chamber defined by said second means, said cylindrical chamber having axial thrust receiving means.
3. The invention claimed in claim 2, in which the axial thrust receiving means includes at least one resilient member.
4. The invention claimed in claim 2, in which the axial thrust receiving means includes at least one Belleville-type annular washer in the cylindrical chamber on each side of the flange.
5. The invention claimed in claim 2, in which the axial thrust receiving means includes at least one roller bearing in the cylindrical chamber on each side of the flange.
6. The invention claimed in claim 2, in which the sleeve has a further outwardly projecting annular flange received within a further substantially cylindrical chamber defined by said second means, said further chamber having further axial thrust receiving means.
7. The invention claimed in claim 1, in which said second means includes shroud means fixed thereto and extending outwardly adjacent the first means at at least two circumferentially distributed locations on the first means, piston means at each location incorporating a piston slidable substantially radially with respect to the axis of the drill string, each piston having an inside face exposed to fluid pressure within said first chamber and an outside face adapted to contact said shroud means, whereby fluid pressure acts through said pistons to urge both impellers into alignment.
8. The invention claimed in claim 7, in which one of the piston means includes a pressure-sensitive valve exposed to the fluid pressure inside said first chamber, the valve having a trip pressure and being so connected that, when the fluid pressure in the first chamber exceeds said trip pressure, the valve admits fluid adjacent the respective piston in such a way as to counteract the fluid pressure seeking to drive that piston radially outwardly, whereby the piston is deactivated and the at least one remaining piston causes angulation of the second means with respect to the first means, whereby the direction of drilling can be controlled by controlling the fluid pressure in the drill string.
9. The invention claimed in claim 8, in which there are two diametrally opposed piston means and the first and second means are constrained to articulate about a fixed axis normal to the axis of the drill string, the two pistons being symmetrically located with respect to the fixed axis.
10. The invention claimed in claim 7, in which there are three piston means circumferentially distributed at 120 degree intervals, each including a pressure-sensitive valve, each valve being connected to a different controllable source of fluid pressure, each valve having a trip pressure such that, when its respective source of fluid pressure exceeds the trip pressure, the fluid is admitted to a location adjacent the respective piston in such a way as to counteract the fluid pressure seeking to drive the piston radially outwardly, whereby the piston is deactivated and the radially outwardly exerted pressure from the other two pistons causes angulation of the second means with respect to the first means, whereby the direction of drilling can be controlled by controlling the fluid pressures going to the separate valves.
11. In combination:
a non-rotary drill string including a pipe member having a central passage for carrying fluid under pressure, at least three circumferentially distributed first arms each mounted at one end to the pipe member for swinging movement in a different plane containing the axis of the pipe member, for each first arm a second arm pivotally connected at one end to the other end of its respective first arm such that each second arm moves in the same plane as its respective first arm, a slidable sleeve mounted on the pipe member, the other ends of the second arms being pivotally connected to the sleeve, the sleeve having a surface in part defining a chamber to which fluid under pressure is admitted from the pipe member, such fluid seeking to move the sleeve in the direction of said first arms so that each articulated combination of first and second arms tends to geniculate and urge their common pivot location radially outwardly with respect to the pipe member thus centering the pipe member when it is located in a bore hole.
a non-rotary drill string including a pipe member having a central passage for carrying fluid under pressure, at least three circumferentially distributed first arms each mounted at one end to the pipe member for swinging movement in a different plane containing the axis of the pipe member, for each first arm a second arm pivotally connected at one end to the other end of its respective first arm such that each second arm moves in the same plane as its respective first arm, a slidable sleeve mounted on the pipe member, the other ends of the second arms being pivotally connected to the sleeve, the sleeve having a surface in part defining a chamber to which fluid under pressure is admitted from the pipe member, such fluid seeking to move the sleeve in the direction of said first arms so that each articulated combination of first and second arms tends to geniculate and urge their common pivot location radially outwardly with respect to the pipe member thus centering the pipe member when it is located in a bore hole.
12. The invention claimed in claim 11, in which there are three said first arms spaced at 120 degree intervals.
13. The invention claimed in claim 12, in which the first arms are all substantially identical, and in which each second arm is substantially the same length as its respective first arm.
14. The invention claimed in claim 11, in which the pivot axis between each second arm and its respective first arm is restrained from moving inward toward the axis of the pipe beyond a location where it lies outwardly of a hypothetical straight line extending between the pivot axes at said one end of the first arm and said other end of the second arm.
15. The invention claimed in claim 11, in which the drill string supports a drilling head at one end, and in which said first and second arms are located adjacent the drilling head.
16. The invention claimed in claim 11, in which said first and second arms are outwardly bowed.
17. In a non-rotating drill string which incorporates a plurality of hollow concatenated pipe sections, a resilient flexible joint between two longitudinally adjacent such sections, one section having first means defining a curvilinear cavity at the joint, the cavity being a surface of revolution about an axis transverse to the drill string, the other section having second means defining an insert complementary with said cavity and received snugly but slidably therein, annular compression spring means located around the drill string adjacent the location of the flexible joint, the said two pipe sections being secured to respective annular support portions on either side longitudinally of the spring means, whereby angulation of one pipe section with respect to the other causes said support portions to compress the spring means at one circumferential region and to relax the spring means at a diametrally opposed region thereof, so that the spring means will resist such angulation and tend to restore the pipe sections to alignment.
18. The invention claimed in claim 17, in which the spring means is offset longitudinally with respect to the center of curvature of said cavity.
19. The invention claimed in claim 17, in which each pipe section defines a shoulder adjacent the cavity, the two shoulders facing each other and being uniformly longitudinally spaced apart when the two pipe sections are in axial alignment, and in which a resilient means is located between the two shoulders for sealing purposes.
20. The invention claimed in claim 17, in which the cavity comprises two diametrally opposed portions and in which the insert comprises two portions fitting into said opposed portions of the cavity, whereby rotation of one pipe section with respect to the other is restrained.
21. The invention claimed in claim 17, in which the spring means comprises a plurality of conical washers.
22. The invention claimed in claim 19, in which the insert on said other pipe section has two concentric parts of different radii of curvature, the shoulder of said other pipe section being a step between said two parts.
23. The invention claimed in claim 17, in which the cavity is spherical.
24. The invention claimed in claim 20, in which the spring means comprises a plurality of conical washers which are offset longitudinally with respect to the center of curvature of said cavity, each portion of the cavity being spherical in curvature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000513725A CA1252081A (en) | 1986-07-14 | 1986-07-14 | Underground, fluid driven directional drilling device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000513725A CA1252081A (en) | 1986-07-14 | 1986-07-14 | Underground, fluid driven directional drilling device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1252081A true CA1252081A (en) | 1989-04-04 |
Family
ID=4133559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000513725A Expired CA1252081A (en) | 1986-07-14 | 1986-07-14 | Underground, fluid driven directional drilling device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1252081A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110056318A (en) * | 2019-04-23 | 2019-07-26 | 中工国际工程股份有限公司 | A kind of salt hole air reserved storeroom row halogen pipe preventing clogging up device |
-
1986
- 1986-07-14 CA CA000513725A patent/CA1252081A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110056318A (en) * | 2019-04-23 | 2019-07-26 | 中工国际工程股份有限公司 | A kind of salt hole air reserved storeroom row halogen pipe preventing clogging up device |
| CN110056318B (en) * | 2019-04-23 | 2023-12-22 | 中工国际工程股份有限公司 | Anti-blocking device for brine discharge pipe of salt cavern gas storage |
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