Fluid operable power device for well operations

Aug. 29, 1961 g. d. Johnson etal 2,998,084

FLUID OPERABLE POWER DEVICE FOR WELL OPERATIONS

<img file="US2998084A_D0001.tif" />

Aug. 29, 1961

G. D. JOHNSON ETAL

2,998,084

FLUID OPERABLE POWER DEVICE FOR WELL OPERATIONS

Filed July 8, 1957

Sheets-Sheet 2

<img file="US2998084A_D0002.tif" />

Aug. 29, 1961

G. D. JOHNSON ETAL

2,998,084

FLUID OPERABLE POWER DEVICE FOR WELL OPERATIONS

Filed July 8, 1957

Sheets-Sheet 3

<img file="US2998084A_D0003.tif" />

Aug. 29, 1961

G. D. JOHNSON ETAL

2,998,084

FLUID OPERABLE POWER DEVICE FOR WELL OPERATIONS

Filed July 8, 1957

Sheets-Sheet 4

<img file="US2998084A_D0004.tif" />

<img file="US2998084A_D0005.tif" />

S&amp;OA/ -Z,/A/P&amp;W£A/

INVENTORS

BY

<img file="US2998084A_D0006.tif" />

Aug. 29, 1961

G. D. JOHNSON ET AL

2,998,084

FLUID OPERABLE POWER DEVICE FOR WELL OPERATIONS

Filed July 8, 1957

Sheets-Sheet 5

<img file="US2998084A_D0007.tif" />

A 7·7·&lt;Ά&amp;Λ/£Ύ5.

2,998,984

Patented Aug. 29, 1961

United States Patent Office

2,998,084

FLUID OPERABLE POWER DEVICE FOR WELL OPERATIONS

Glenn D. Johnson and Egon R. Lindgren, Houston, Tex., assignors to Joy Manufacturing Company, Pittsburgh, Pa., a Corporation of Pennsylvania

Filed July 8, 1957, Ser. No. 670,405

Claims. (Cl. 175—85)

This invention relates to a fluid operable power device for well operations and equipment and more particularly to a composite variable speed fluid operable power device for transmitting torque to a drilling string and adapted to be suspended as a unit from a well derrick above a well hole or to be mounted in a derrick platform for use as a rotary table.

Generally speaking, this invention contemplates a fluid operable power device comprising a top swivel section mounted for rotation and having a swivel mandrel depending therefrom. Separably attached to the swivel section and surrounding the swivel mandrel is a power section including a plurality of fluid operable motors arranged to drive through a gear means, a rotary sleeve member provided with a tapered seat upon which may be positioned, for example, a kelly bushing through which the swivel mandrel is operably sleeved. When the swivel section and power section are interconnected in assembly and suspended as a unit from a traveling block, torque reaction means are provided to connect the power device to a fixed portion of the drilling rig or derrick. In such interconnected assembly the composite power device may deliver torque to a drilling string and may facilitate assembly and disassembly of pipe in the string. The power section and swivel section may be independently employed and separated and when combined with an adapter device, the power section may be used in a platform of a drilling rig so as to operate as a rotary table while the swivel section is used in normal manner between a traveling block and the drilling string. The separable power and swivel sections generally described above provide numerous advantages in meeting various conditions encountered in well drilling operations.

An object of this invention is to disclose and provide a fluid operable power device for well, equipment embodying a novel arrangement and construction of composite separable power and swivel sections.

An object of this invention is to disclose and provide a fluid operable power section provided with a fluid control system for producing variable speed and torque so as to readily and conveniently adjust the power means to variable drilling conditions.

Another object of this invention is to disclose and provide a novel power device for well operations wherein said power means is designed and arranged to facilitate assembly of a pipe drilling string.

A further object of this invention is to disclose and provide a composite power device in which a torque resistance means is utilized to restrain the power means against rotation when suspended in a derrick and includes means carried by the torque resistance means to facilitate assembly and disassembly of pipe over a well hole.

A more specific object of this invention is to disclose and provide a power section including a plurality of fluid operable motors and a rotary sleeve member driven by said fluid motors, said power section having an adapter device permitting use of said power section as a rotary table, said rotary member having a tapered seat for accommodating adapter members of different construction for transmitting torque forces to a swivel mandrel or to part of a drilling string associated with the swivel mandrel.

Numerous other objects and advantages of this invention will be readily apparent from the following descrip5 tion of the drawings in which exemplary embodiments of the invention are shown.

In the drawings:

FIG. 1 is a fragmentary perspective view of a well derrick equipped with a composite power device embody10 ing this invention.

FIG. 2 is a fragmentary perspective view showing an operative position of pipe make-up means shown in FIG. 1.

FIG. 3 is a fragmentary elevational view showing a 15 pipe latch means used with the pipe make-up means shown in FIGS. 1 and 2.

FIG. 4 is a fragmentary elevational view of the power device shown in FIG. 1, the view being partly in section, the section being taken in a vertical plane passing 20 through the axis of the power means.

FIG. 5 is a fragmentary enlarged partially sectional view of the power device shown in FIG. 4 with the power section adapted for use as a rotary table, a kelly bushing adapter member being shown.

FIG. 6 is a fragmentary sectional view taken in the same plane as FIG. 5 showing the power section with an adapter member for cooperation with pipe slips.

FIG. 7 is an enlarged perspective view of torque-resisting means shown in FIG. 1.

FIG. 8 is a fragmentary perspective view of the power section separated from the power swivel as when the power section is used as a rotary table.

FIG. 9 is a schematic diagram illustrating fluid control means for the power means shown in FIG. 1.

3® In FIG. 1 a well drilling rig fragmentarily shown may comprise a well derrick 15 including a platform 16. A traveling block 17 may be suspended from derrick 15 in a well known manner and includes a suitable hook means 18 carrying a bail 19 which may be con⁴⁰ nected in any suitable well known manner to a composite fluid operable power device 20 embodying this invention. The power device 20 is illustrated as connected to a drilling string 22 for imparting torque thereto. The power device 20 may be connected to a conduit 23 ⁴⁵ for circulation of drilling fluid or mud through the well hole and drilling string. Torque reaction transmitting means 24 including torque colume or member 25 is provided to hold the power device against rotation when torque is applied to the drilling string.

⁵⁰ The composite power device 20 is best described by reference to FIG. 4. Power device 20 may comprise an upper swivel section generally indicated at 28 and a lower power or driving section generally indicated at 29, said swivel and power sections being readily connected ⁵⁵ together or separated for operation under various drilling conditions. The swivel section 28 may include a swivel housing 30 comprising an upper housing portion 31 and a lower housing portion 32 interconnected as by interengaged threads at 33. The upper housing portion ⁶⁰ 31 may be provided with a top externally threaded portion 34 having a threaded connection with a support and hose fitting 35. Fitting 35 is provided with an internally threaded tapered socket 36 for threaded connection to a hanger member 37 which may be secured to θ® and supported by bail means 19. The fitting 35 may be provided with a goose neck passageway 38 affording communication with mud conduit 23 and with the internal passageway of a drilling string through the power means as hereafter described.

'° The upper swivel housing portion 31 carries an inner axial rotatable sleeve 40 having its top open end in com

2,998,084 munication with passageway 33. Between sleeve member 40 and housing portion 31 may be provided a cylindrical packing 41 retained at its top by a packing ring 42 secured to and carried by the top edge of threaded portion 34 of the housing portion 31.

Supported within the swivel housing 30 for rotation may be a swivel mandrel 44 provided with a swivel head 45 antifrictionally supported within swivel housing 30. The swivel head 45 includes an enlarged shoulder portion 46 providing a downwardly directed annular face 47 opposed to an upwardly directed annular face 48 on the bottom swivel housing portion 32. The faces 47 and 48 provide seats for a thrust bearing means 49 for supporting the swivel mandrel 44. Spaced ball bearing means 50 and 51 may be provided between swivel head 45 and the upper housing portion 31 and lower housing portion 32 to antifrictionally mount the swivel mandrel head 45 for rotation therein. The top of mandrel head 45 may receive the lower end of the sleeve member 40 which may be provided with an external annular rib 54 cooperating with securement and packing means 54α to retain and position the sleeve 40 in coaxial relation with the mandrel. Seal means 55 may be provided at the bottom of housing portion 32 for sealing against the lower portion of swivel head 45. The swivel mandrel 44 is provided with an axial through bore 56 in communication with the sleeve member 40 and with passageway 38 and is rotatably mounted within the swivel housing.

The swivel mandrel 44 may include an intermediate section 58 of polygonal or square cross section so as to provide a driving connection with the power section 29 as later described. Below intermediate square section 58 the swivel mandrel 44 may include a cylindrical bottom portion 59 provided at its end with tapered external threads 60, said threads 60 being adapted for connection to internal threads provided on a coupling on a drilling string or the threads at the end of a pipe section.

The power section 29 may include a bottom generally bowl shaped housing 64 and an upper housing 65 of generally L-section, said housing 64 and 65 being connected together by suitable bolt assemblies not shown. The upper housing 65 of L-section may include an upstanding cylindrical wall 66 integral with a horizontally and outwardly extending wall 67 of relatively thick section, said walls 66 and 67 being reinforced by external webs 68 spaced circumferentially around wall 66. The cylindrical wall 66 may be connected to the bottom portion of swivel housing portion 32 by suitable bolt assemblies 69. The wall 67 may extend inwardly of wall 66 to provide an annular seat 70 for a bottom race 71 of a tapered roller bearing means 72, said bearing means 72 having an upper race 73 seated against a downwardly facing annular shoulder 74 provided on a driven rotary sleeve member 76. The rotary member 76 includes an upper head portion extending upwardly from within the cylindrical wall 66 of the housing 65 into the lower hollow bottom portion of the swivel housing 32. Packing or seal means 77 may be provided between the external cylindrical surface of the top portion of the rotary member 76 and opposite internal cylindrical surfaces on wall 66.

The upper portion 78 of the rotary member 76 may include an internal tapered seat 79 adapted to receive selected adapter members for interconnecting the sleeve member 76 in operable relation to a drill string; in this example, a kelly bushing 89 is shown. The head portion 78 includes an internal upwardly facing annular recess 81 adapted to receive a top circumferential flange 82 on kelly bushing 80. Top flange 82 of the kelly bushing may be provided with diametrically opposed key slots 83 to receive a key 84 secured by a set screw 85 to fix the kelly bushing 80 in head portion 78. The kelly bushing 80 includes a through bore 86 having a section corresponding to the polygonal section 58 of the swivel ⁴mandrel and receives section 58 therein in driving engagement therewith.

The rotary member 76 includes a tubular portion 88 depending from the head portion 78 and provided at its lower end with a seat 89 fbr ^;a ball bearing means 90 which may also be seated on a lower section of the power housing 64. The rotary member 76 is thus rotatably supported in alignment with the axis of the swivel mandrel 44. A lower skirt 91 of power housing 64 may carry an adapter member or spool 92 secured thereinto as by stud bolts 93, said adapter spool 92 affording connection to means such as tubing heads and blow out preventors when said power section is used as a rotary table. Between spool 92 and the lowermost portion of the tube 88 may be provided suitable seal or packing means 94, said spool 92 having an annular recess to carry said seal means 94.

The power housing 64 may be provided with circumferentially spaced recesses 100 within which may be supported fluid motors 101, each fluid motor being connected to a motor mounting plate 102 secured to top wall 103 of the recess 100 by bolt assemblies 104. Each fluid motor is provided with an upwardly directed motor shaft 105 having an axis parallel to the axis of the rotary member and which extends into a keyed bore 106 of a pinion gear 107. Pinion gear 107 may be supported in a lower bearing means 108 carried by wall 103 and upper bearing means 109 carried by wall 67 of the L-shaped housing 65. The pinion gear 107 is provided with a plurality of longitudinally extending teeth having meshed engagement as at 110 with external teeth of a spindle ring gear 111. The ring gear 111 may be secured to tube 88 of the rotary spindle member 76 by seating an inner hub 112 thereof against a shoulder 113 on the external surface of tube -88 and by securing hub 112 thereagainst by a collar 114 threaded at 115 on tube 88. A key 114' secures gear 111 and tube 88 against relative rotation. Suitable lock means, not shown, may be employed to lock collar 114 against rotation. As a fluid motor 101 is driven by pressure fluid as later described, it will be readily apparent that pinion gear 107 drives ring gear 111 to rotate the rotary member 76 to drive the swivel mandrel through the kelly bushing in rotation.

An oil pump for lubricating the several bearing means carried by the power section may comprise a pump means 118 carried within housing 64 and provided with a gear 119 having engagement with teeth of the ring gear 112. A tube 120 provided with a filter device 121 may provide means for circulation through suitable conduits of lubricating oil throughout the power housing 64.

When the power device 20 is suspended from a traveling block 17 as shown in FIG. 1, means are provided for restraining the power device against rotation during operation. The means includes a torque member or column 25 which may be secured at its bottom as at 125 to platform 16 in suitable manner. The torque column 25 may be of any selected length and of polygonal section illustrated as square section and secured at its top to a securement means 126 which may comprise a cylindrical element connected as by arms 127 to the well derrick 15. The torque column 25 is disposed parallel to the axis of the drilling string or well hole and in selected spaced relation thereto.

The torque means 24 interconnects the power housing of the power device to the torque column 25 to restrain rotation of the power device and is afforded vertical movement relative to the torque column 25. The means 24 is best shown in FIG. 7 and may comprise a pair of torque arms 129 of any suitable metal section illustrated as an I-section. At one end, each arm 129 is provided with spaced ported brackets 130 each adapted to be interposed between spaced pairs of ported lugs 131 carried by the power housing. A. pin 132 extending through the ported brackets 130 and lugs 131 serves to secure

2,998, δ dach arm 129 to the power housing. The outer ends of arms 129 may each be provided with ported flange extensions 134, and ported spaced ends 135 of an interconnecting member 136 may be alignably positioned therewith for reception of securement pins 137. The 5 member 136 may be of any suitable construction including longitudinally spaced webs 138 provided with top and bottom flanges 139 of suitable configuration to provide necessary strength. Intermediate the ends of member 136 the webs 138 and top and bottom flanges 10 139 are connected to a central means 140 forming four chambers 141 disposed around the column 25 and having inner openings facing the column 25. Within each chamber 141 may be disposed a roller 143 antifrictionally mounted on horizontal axles 144 carried by the means 15 140 so that the cylindrical face of each roll 143 may rollably engage a longitudinal face 145 of the torque column 25. Thus, as the power device is vertically moved above the well hole, the torque arm may ride in rolling engagement with torque column 25 and re- 20 strain the power device against rotation at any vertical position thereof.

Means to facilitate assembly and disassembly of a pipe string may be carried by the torque column 25 and may be used in association with the power device 25 when the device is suspended from a traveling block. The means for assembly and disassembly of pipe may comprise a pipe carrier means including a bottom horizontally extending member 148 connected to the bottom of torque column 25 by a cylindrical collar 149 antifric- ³⁰tionally mounted so as to permit relative swinging movement of arm 148 with respect to torque column 25. The outer end of horizontal bottom member 148 may be provided with an upwardly facing hollow socket 15® adapted to receive the bottom end of a pipe length 151. ³⁵

At the top of torque column 25 may be provided a top horizontal downwardly offset member 153 having a collar 154 antifrictionally mounted at the top of column 25 for relative rotation therewith. The outer lower off-set portion 155 of member 153 may be intercon- ⁴⁰nected with the bottom member 148 by a vertical member 156 so that top and bottom members 153 and 148 may move together. The outer end of portion 155 may carry a U-shaped member 157 having an opening 158 through which an upper portion of a pipe length 151 45 may be moved.

The U-shaped member 157 may be provided with a pipe-retaining latch element 159 adjacent the opening 158 so as to retain the upper portion of a pipe length therewithin. The latch element 159 may extend through 50 the inner leg of member 157 for pivotal connection at 160 with a bracket 161 carried by the leg. The element 159 may be integral with a latch arm 162 provided with a connection at 163 to a depending release cord 164 which depends to a height to permit convenient grasp- 55 ing by an operator standing on platform 16. The latch arm 162 may be biased by a spring (not shown) into latched position so that the latch element 159 will be normally closed and will be releasable upon a downward pull given to the release cord 164. The manner of 60 operation of the pipe carrier means described above will be explained later.

A fluid means or system for controlling the speed and torque of the power device 20 is shown in FIG. 9, which includes a schematic diagram of the variable fluid con- 65 trol means. This fluid control means provides in effect a hydraulic transmission permitting selection of variable speeds from 0 to maximum r.p.m. of the power device and to vary the amount of torque produced by the fluid motors. In FIG. 9 a prime mover or engine indicated 70 at 170 may be connected through a coupling 171 to a plurality of hydraulic pumps 172α, 1725, and 172c, arranged in tandem and of selected gear face size, for example, pump 172α may be a 3 pump and pumps 1726 and 172c may be 1 ^J/z pumps. Each of the pumps is provided 75

084 with suction lines 173α, 1736 and 173c to a reservoir or supply of hydraulic fluid indicated at 174. The discharge of pump 172α may be connected to a feed line 175 which is connected at its other end to a four way hydraulically operated spring loaded open center valve 176. The valve 176 is connected to motor conduit lines 177 and 178 which connect the fluid operable motors 101 in parallel. In the schematic diagram two fluid motors 101 are shown although it is understood that one or more fluid motors may be employed. The valve 176 is provided with a discharge line 179 connected to reservoir 174.

Pump 1726 is connected to a feed line 1756 which may be connected at 180 to the feed line 175 of the pump 172α. Similarly pump 172c is connected to a feed line 175c which is connected to the feed line 175 at 181 between the four-way valve 176 and the connection 180 of line 1756 thereto. Each of said feed lines 1756 and 175c may be provided with suitable check valves 182 and 183 respectively. Each of the feed lines 1756 and 175c may be provided with pilot pressure controlled unloading or relief valves 184 and 185 respectively, each of said relief valves being set to unload fluid in their respective feed lines at preselected pressures and to return fluid through lines 186 and 187 to reservoir 174. The feed line 175 may be similarly provided with a relief valve 189 to discharge fluid at a selected pressure through line 190 to reservoir 174. For purposes of an exemplary description the pump 172α may deliver fluid at 45 gallons per minute at 1500 p.s.i. and relief valve 189 is set to discharge at pressure exceeding 1500 p.s.i. Pump 1726 may deliver fluid at 22.5 gallons per minute up to 970 lbs. p.s.i. and unloading valve 184 will open at pressures about 970 p.s.i. Pump 172c may deliver fluid at 670 p.s.i. at 22.5 g.p.m. and unloading valve 185 will relieve fluid pressure when it exceeds 675 p.s.i. Below pressures of 675 p.s.i the combined oil delivery of pumps 172α, 1726 and 172c is therefore 90 g.p.m.

The variable fluid control means also includes an auxiliary low pressure gear pump 192 driven through suitable pulley drive means 193 from the drive between the engine 170 and the pump 172α. The low pressure pump 192 is provided with a suction line 195 in communication with reservoir 174. The auxiliary pump 192 may discharge into a fluid control line 194 which may be connected to an engine throttle pilot valve 196, a forward, neutral, and reverse pilot valve 197 and a speed change control valve 198, each of said valves having discharge lines leading to reservoir 174. The control line 194 is also provided with a relief valve 200, in this example, set to relieve pressure in excess of 50 p.s.i. and to discharge through line 201 into the reservoir 174. A gage 202 is provided in line 194 to record pressure of the auxiliary pump 192.

Each of the pilot valves 196, 197, 198 may be electrically operated solenoid type valves. Throttle pilot valve 196 may be a four-way valve and may be connected to a throttle switch means 204 through electric leads 205 in well known manner. Similarly pilot valve 197 may be a four-way valve connected to switch means 206 through electric leads 207. Valve 198 may be connected to switch means 208 through an electric lead 209, said valves being grounded at 210. Any suitable electrical power source such as a battery 211 may be provided for supplying current to the switch means 204, 206, and 208.

The pilot valve 197 is connected through low pressure fluid pilot lines 213 and 214 to the four-way valve 176.

The throttle pilot valve 196 may be connected through lines 216 and 216α to· opposite ends of a double acting fluid cylinder 217 provided with a piston 218 which may be connected by suitable linkage means (not shown) to a throttle member on engine 170 for controlling at a remote location the speed of engine 170 through fluid from the auxiliary low pressure pump 192. The switch means 204, 206 and 208 may be located on a control panel to be operated by an operator and also at such control panel

2,008,084 ί

may be a volt meter 220 graduated in p.s.i., said volt member 220 being connected to a pressure transducer 221 connected to the feed line 175 at 222 so that the fluid pressure being delivered to the four-way hydraulically operated valve 176 may be indicated.

In the example, engine 170 may be of 45 H.P. with maximum r.p.m. of 1600. It will be understood that the r.p.m. of the fluid motors is directly dependent upon the amount of fluid in gallons per minute delivered to the motors and the torque which the motors are capable of deliverying depends upon the pressure of the fluid delivered to the fluid motors. Thus, at low speeds a high torque value can be obtained and when torque requirements are low, speed can be increased without changing the amount of input H.P. The fluid control system described above enables one or more pumps to· be automatically or manually disconnected as torque requirements increase so that more fluid pressure can be delivered by the pump as the total number of pumps utilized is decreased and without change of input H.P.

Assuming that operating conditions make it desirable to rotate the power device at maximum r.p.m. the throttle switch 204 may be closed to actuate the throttle pilot valve 196 permitting auxiliary low pressure fluid to flow to the cylinder and piston means 217 and 218 to urge the engine throttle to maximum advanced position until the engine is running at its maximum speed of 1600 r.p.m. In this condition the pumps 172α, 1726 and 172c deliver fluid through their respective feed lines to four-way valve 176. Valve 176 is a spring loaded open centered valve and thus will normally pass fluid from the pumps directly back to the reservoir 174. When switch means 206 is closed in either direction at the operator’s discretion for producing forward or reverse rotation of the swivel mandrel, the pilot valve 197 is actuated which delivers auxiliary pump fluid under pressure to valve 176 causing the valve to open and deliver fluid from the pumps 172α, 1726 and 172c through the conduits 178 or 177 to the fluid motors.

Increase in torque demand to a point where 675 lbs. p.s.i. of pump 172c is exceeded causes the unloading valve 185 to open and to discharge fluid delivered by pump 172c back into the reservoir instead of transmitting said fluid to feed line 175. Higher fluid pressure and thus more torque is low available at the power device without overloading the engine 170 because only pumps 172α and 1726 are effectively pumping fluid. Under this condition in this example, the amount of fluid delivered to the fluid motors is reduced from 90 gallons per minute to 67½ gallons per minute, and therefore the speed of the fluid motors will be decreased.

By operation of the throttle switch means 204 the engine speed can be changed between 1600 and 710 r.p.m. and such speed change will also regulate the amount of fluid delivered from any one of . pumps 172α, 1726 and 172c or combination of pumps.

VZhen torque requirements further increase so that 970 p.s.i is exceeded gear pump 1726 will unload through unloading valve 184 and only pump 172α will deliver fluid to the four-way valve 176. Under these conditions fluid pressure may now be increased to 1500 p.s.i. and the amount of fluid delivered will decrease to 45 gallons per minute. The speed and therefore oil delivery of this pump 172α can be further controlled by further manipulation of the throttle switch means 204.

It will thus be apparent that throughout a wide range of torque requirements and drilling speeds the fluid control means described above permit variable speed and torque control by selective manipulation of the throttle switch means 204 in order to control the speed of the prime mover engine 170 and by automatic or manual control through switch 208 and pilot valve 198 of unloading valves 184 and 185.

Torque requirements may vary as drilling progresses and there is the possibility that as torque load momentarily decreases and fluid pressure simultaneously decreases therewith one or both of the unloading valves 184 and 185 may close. Such closing of these unloading valves may bring into the fluid control system one or both of 5 the gear pumps 1726, 172c, which would again deliver oil to the four-way valve 176 and increase the speed of the fluid motors. Such a condition may produce undesirable fluctuation of rotating speeds of the drilling string and to prevent such undesirable speed fluctuation the pilot 10 valve 198 is provided. When switch means 208 is closed, the three-way speed change pilot valve 198, is energized to deliver auxiliary pump fluid to· both unloading valves 184 and 185 through line 224. As long as switch means 208 is closed, auxiliary fluid pressure through line 224 will 15 maintain unloading valves 184 and 185 open and thus prevent speed fluctuations of the swivel stem at the.higher fluid pressure range where torque demand may vary.

It will be readily apparent that rotation of the swivel stem is reversed by closing the other contact of switch 20 means 206 to actuate the pilot valve 197 to its other position and to thus reverse the flow of fluid through conduits 177, 178 to the fluid motors. The position of the engine throttle may be controlled by positioning of the hydraulic piston 218 in the double acting cylinder 25 means 217 through momentary depression of switch means 204. When the throttle switch means 204 is in neutral position, the piston 218 does not move and the throttle will remain in fixed position. Under non-varying load conditions, the engine speed will be constant, how30 ever, the engine may change its speed depending upon the load to which it is subjected.

It should also be noted that when speed control switch means 208 is closed the unloading valves 184 and 185 remain open and only pump 172α delivers fluid to the 35 fluid motors. Thus at a control panel selectively located on . a drilling rig and comprising switch means 204, 206, 208 and pressure gage 220, an operator may read on the gage 220 fluid pressure being delivered to the fluid pumps and control through the switch means the torque 40 and speed of the swivel mandrel carried by the power device 20.

The advantages in operation of the above described power device 20 and fluid control means will be readily understood. When the power device is suspended from 45 a drilling rig for drilling a well hole, the power device and associated fluid control means permit selected torque and speed of rotation to be imparted to the drilling string through the three switch means 204, 206 and 208. The power device may be vertically movable during a drilling ⁵⁰ operation and eliminates the necessity of long kelly stems. Furthermore, since the power source for drilling comprises fluid motors held above the platform and since the fluid conduits to the motors are provided with ample slack to be carried along derrick members, the space on ³³ the platform is free and open and not cluttered with chain drives and other drive equipment usually employed with other rotary drilling rigs.

The suspension of power device 20 above the hole also facilitates assembly and disassembly of the drilling ³³ string. In FIG. 1 to FIG. 3 inclusive, the opening in the platform 16 may be provided with a slip adapter member to permit the use of pipe slips of usual construction to hold a pipe string in the well hole. In assembly, a pipe length 151 may be placed with its lower end in socket ⁶³ 150 of the pipe carrier and the upper end of the pipe length 151 may be inserted in the U-shaped member 157. With the top end of the drilling string held in the pipe slip adapter member in the platform, the pipe length 151 may be swung in the pipe carrier into axially aligned ⁷⁰ position above the drill string and below the raised power device 20. The power device may then be lowered and rotated so as to make up the threaded connection between the swivel mandrel and the top end of the pipe 151. After the connection is made, the power device may be ⁷³ slightly raised to lift the pipe length 151 out of the sock

2,998,084 et. The pipe carrier is thus released and may be returned to its initial position. The lower end of the pipe length 151 may be guided to the coupling of the drill string. Slight lowering of the power device and rotation thereof will assemble the pipe length 151 with the drilling string. After the connection has been properly made up, the drilling string may then be raised so as to' release the pipe slips and the drilling operation continued by driving the power device in its raised position.

Disassembly of a pipe string may be made in substantially the reverse manner to that described for assembly of a pipe string. The drilling string may be raised to a selected height so that the drilling string at a coupling below the length to be removed may be secured with pipe slips in a pipe slip adapter member carried by the platform. The power device may be caused to rotate so as to release and unthread the pipe length from the coupling just above the pipe slips. The disconnected pipe may then be lifted slightly and the pipe carriers swung into position so that the bottom end of the disconnected pipe length may be inserted into the socket on the carrier. The upper end may also be moved into engagement with the upper U-shaped member 157. The lower end of the pipe length may be restrained against rotation by manual means while power device is being unthreaded from the top end thereof by rotation imparted to the swivel mandrel. When the disconnected pipe length is free from the power device, the pipe carrier may be moved to the side of the platform where the disconnected pipe length may be removed from the pipe carrier and racked in well known manner. The power device may then be lowered to be temporarily threadedly interconnected with the upper end of the drill string held in the pipe slips. The drill string may then be raised and the same sequence of disassembly operations may be carried out so as to disassemble another pipe length from the drilling string.

It will thus be readily apparent to those skilled in the art that the employment of the combination or composite power swivel and power device in the manner above described readily facilitates assembly and disassembly of pipe and that such disassembly or assembly operation may be carried out with greater ease and less danger than as has been heretofore done.

The power device may be separated into a separate power swivel and a separate power means so that the power swivel may be employed in well derricks in usual manner. The power means of the power device may be readily installed as a rotary table in a derrick platform. The adapter spool 92 at the bottom of the power housing is readily attachable to well equipment such as blowout preventers or the like provided at the top of a well hole. When the power section is installed in the platform and is used as a rotary table, it will be readily understood that the fluid conduits feeding fluid to the fluid motors may be readily arranged below the platform and out of the way of a drilling crew. The head portion of the rotary sleeve member provided in the power section is exposed above the platform and the tapered seat 79 therein may readily cooperate with a selected adapter member in order to permit a desired well operation. For example, in FIG. 5, such an adapter member is illustrated as a kelly bushing 80' of construction similar to that shown in FIG. 4. The kelly bushing in FIG. 5 may be provided with a square section opening so as to receive an elongated stem 230 for a drilling operation. The swivel section may be spaced above the power section and may be connected to a kelly stem 220 in usual manner.

When the power section is used as a rotary table during assembly and disassembly of pipe from a drill string, a kelly bushing 80' may be removed and in its place may be provided a slip adapter member 232 which seats on the tapered seat 79 of the headed portion of the rotary sleeve member 76 in virtually the same manner as kelly bushing. The slip adapter member 232 is provided with an internal tapered slip-receiving face 233 spaced from a drill string

234 which passes therethrough and which may extend slightly above the top face of the headed portion of the rotary member. In FIG. 6, an exemplary pipe slip means 236 is shown engaging a drill string 234 with the pipe slips inserted into the pipe slip adapter member so as to hold a drill string in suspension in a well hole. It will thus be apparent that when the swivel section and power section are disassembled, the power section may be utilized as a rotary table in a convenient manner.

It will be readily understood by those skilled in the art that one or more fluid motors may be employed to drive the power section and that various fluid control means may be used to impart a desired torque and speed to the fluid motors. It will also be understood that the interconnected power swivel section and the power section may be modified in construction and that gear means for transmitting the power from the fluid motors to the rotary sleeve member and to the swivel mandrel may be modified and changed.

It will be also understood that the torque reaction means for restraining the power section against rotation when suspended within a well derrick may be of different construction and under some conditions of operation may not require a rigid torque column as shown. For example the torque reaction means may include a pair of vertically extending parallel flexible torque absorbing members such as wire cables connected at their bottom ends to the torque floor and at their top ends to selected points on the derrick structure above the floor. The wire cables may be angularly spaced about the vertical path of travel of the power section and may include diametrically opposed cables. A rigid torque member connected to the power section may be provided with a suitable roller assembly at its outer end for providing a vertically movable connection to an associated wire cable. The roller assembly may be of suitable construction and preferably may be quickly detachable from the wire cable by a suitable quick opening device. It will be understood that the torque reaction means described above and shown in the drawings is exemplary only.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.