US3058510A - Well-drilling turbines - Google Patents

Description

Oct. 16, 1962 w. T'RAsPoLsKY ETAI. 3,058,510

wELL-DRILLING TURBINES Filed June 26, 1958 2 Sheets-Sheet 1 Oct. 16, 1962 w. TIRASPOLSKY ETAL 3,058,510

WELL-DRILLING TURBINES 2 Sheets-Sheet 2 Filed June 26, 1958 Unite States Patent @ddee 3,658,510 Patented Oct. 16, 1962 3,058,510 WELL-DRlLLlNG TURBDES Wladimir Tiraspolsky, 69 Ave. Victor Cresson, Issy-les- Moulineaux, France, 'and Roger Franois Rouviere,

Castor, Lot 24, Aurelhan, France Filed .lune 26, 1958, Ser. No. 744,749 'Claims priority, application France .luly 11, 1957 11 Claims. (Cl. 253-3) The present invention relates generally to well-drilling turbines.

lt is known that in order to enable a well-drilling turbine to drive a drilling bit or similar tool resting upon the rock to be drilled and exerting upon the same a preset force often called weight on the bit, it is necessary that said turbine should overcome the resistant torque exerted by the drilling bit when rotated under the given conditions. The meaning of some terms used in the technical eld of the drilling turbines is given hereinafter.

Specific torque of tz bit-This is the torque which is required for rotating a bit of defined type during a drilling operation in a determined ground per ton of weight put on the bit, the total torque being approximately related to the force with which the bit is applied against the bottom of the bore hole.

Resistant torque-This is the resistance offered by the ground to the rotation of the bit. Assuming Msp to be the specific torque of the bit, M to be the resistant torque and W to be the weight exerted upon the bit, we have the following relation:

M bit W Power torque- This term defines the driving torque transmitted from the turbine to the bit.

Specz'c torque of the turbina- This is the ratio between the power torque which is transmitted from the turbine to the bit at a given time and the reactive stress of the bit.

Weight on the tol.-This is the force with which the bit is applied against the `bottom of the bore hole.

Reactive stress of the tomi-This means the reaction transmitted from the tool or bit to the rotor part of the turbine.

For a given output, a well-drilling turbine of the existing type can transmit to the driving shaft a well determined torque for each rotational speed.

ln order to take full advantage of the torque which is transmitted by the turbine at the drilling bit, the axial reactive stress thereof ought to be equal to the axial thrust upon the turbine rotor. Actually, where these two stresses are not equal, the algebraic dillerence will be absorbed by the turbine bearing which will in turn require a power which may be substantial. The power required by the turbine bearing involves an increased wear of the latter, i.e., a reduction of the service duration of the turbine during the time interval between overhauls or repairs.

Moreover, the power curve of a turbine has a well defined crest which is generally close to the maximum hydraulic efciency. There is, obviously, an advantage not to deviate in either sense too far from the rotational speed corresponding to the maximum eciency. There is, however, only one combination of speed, resistant torque, and weight upon the tool which, for a predetermined turbine, corresponds to the maximum of etliciency. As soon as the resistant torque of the drilling bit is varied, a deviation takes place from the power maximum or from the position of axial equilibrium of the bearings because the specific torque of a given turbine cannot be altered except by deviating from the rotational speed which connotes the maximum power or, alternatively, by loading the axial bearings in the one or the other direction. However, loading the bearings involves disadvantages as aforesaid.

Where the requirements enforced by the tool, or by the nature of the soil to be drilled, deviate from the range of specific torques that may be obtained from a given turbine, another turbine having a different construction and other characteristics has to be used. There are, however, cases outside the range of normally possible combinations of the speed factor, resistant torque factor, and weight upon the tool factor which are available with existing turbines.

lt is an object of the invention to provide .a well-drilling turbine devoid of the aforesaid disadvantages and so built as to permit axial bearings to be unloaded during the drilling process.

Another object of the invention is to provide a well drilling turbine so built that the specific torque of a turbine can `be altered for .any given speed, but more particularly at the speed that corresponds to maximum power without any need for loading for that purpose the axial bearings of the turbine while generating a compensating axial thrust in the required direction which modifies the parameter (tool reaction) used for. determining said speciiic torque.

It was previously proposed for the purpose of unloading the bearings of a turbine to arrange over the turbine shaft a revoluble piston whose cylinder is rigid with the turbine body and has an outlet located outside in the annular space of the well. However, this arrangement presents a disadvantage, namely, that of causing a liuid leakage, which increases with wear, at the input end of the turbine, thereby reducing the fluid volume which flows through the turbine and reaches the drilling bit. Moreover, this known arrangement is only operative in one direction, i.e., in the direction corresponding to a reduction of the axial thrust exerted upon the turbine.

The invention is embodied in a well-drilling turbine comprising means for utilizing inside the turbine, or in an overlying joint, a hydraulic pressure diferential, and means subjected to this pressure differential for transmitting the same to the rotor part of the turbine in the form of an axial thrust of selected direction.

According to a suitable constructional form of the invention, means are provided for creating inside the turbine a communication between two points where different pressures prevail so as to provide on said communication means, or on associated elements, the required pressure differential, said means being connected to the rotor part of the turbine for transmitting thereto the required axial thrust.

Several devices of this type might be so associated as to multiply the resultant effect or to combine different effects.

The generated compensating force, which performs regulation of the specic torque of the turbine may be arranged for operating on a turbine having a predetermined construction. Alternatively, it may be regulatable during the course of the operation or automatically adaptable to the working requirements of the tool.

With the aforesaid, and such other objects in view as will incidentally appear hereafter, the invention comprises the novel construction and combination of parts that will be now described, by way of example, with reference to the accompanying diagrammatic drawings forming a part of this disclosure and wherein:

FIG. 1 is a part sectional elevational view of a turbine utilizing the pressure drop between the top 4and any point of the stacked structure for procuring a compensating effect of the axial thrust, and

FIGS. 2 to 7 are part sectional views of constructional modifications.

The turbine represented in FIG. l comprises a body portion 1 surmounted by a joint 2 and carrying a stator part stack 3 of known type. This turbine has a hollow shaft 4 through which is provided a channel 5. Said shaft 4 carries in the usual fashion a stack of rotor parts 6. Lower passages or channels 7 insure communication between the shaft channel 5 and any desired point situated underneath the stack of rotor parts or an intermediate point. The stack of stator parts 3 and the stack of rotor parts 6 are suitably associated with axial bearings 62.

According to the invention, there is provided in the turbine an upwardly directed compensating thrust which is exerted on the head end of the turbine shaft, wherefor the shaft 4 is provided at its upper end with a piston 8 housed for sliding motion in a stationary cylinder 9. Gasket segments 10 provide a sealing effect. The cylinder 9 is secured by a nut 11 to a bridge or spider member 12 rigid with the joint 2. The channel 5 in the shaft 4 communicates with the chamber 14 in the cylinder 9 which overlies the piston 8, through a nozzle 13.

The operation of the device thus constructed is easy to understand from the drawings:

Actually `a pressure P1 normally prevails above the turbine stacks of parts. This pressure P1 exerts an upwardly directed pressure upon the underface 63 of piston 8 and consequently upon the rotor structure of the turbine. However, the chamber '14 de-ned inside the cylinder 9 above the piston 8 communicates with a point of the rotor part stack where a pressure lP2 smaller than P1 prevails. This pressure P2 acts upon the surface 64. This provides the pressure differential Pl-Pz which applies the required compensating thrust to the rotor parts of the turbine. This compensating pressure is subtracted from the initial thrust which is exerted upon the blades of the rotor structure. The nozzle 13 limits the fluid flow around the piston 8 when the packings 10 have undergone undue wear.

According to the constructional form shown in FIG. 2, the body portion 1 of the turbine is surmounted by a joint 1-6 having a cylinder 17 secured therein which forms channels or passages 18 with the joint 16 through which the circulating fluid may flow. The cylinder 17 is open at its upper end and serves as a guiding member for the piston 8 carried by the turbine shaft 4. The lower end of the cylinder 17 surrounds the shaft 4, sealing gaskets 19 being interposed therebtween. Channels 2t) establish communication between the chamber 21 in the cylinder 17 and the channel 5 in the shaft 4.

lDuring the operation of the turbine, the pressure P1 which prevails over the set of blades of the turbine is operative on the upper face Y65 of the piston 8 while its lower face 66 is subjected in the chamber 21 to the `action of the lower pressure P2 which prevails at the required point of the set of blades of the rotor structure or underneath the latter. Thus, there is obtained a downwardly directed additional differential pressure which is added to the pressure as normally exerted on the rotor structure, thereby modifying the specific torque of the turbine which acts upon the tool.

According to the constructional lmodiiication shown in IFIG. 3, the body portion 1 of the turbine is surmounted by a joint -23 having an annular throttle 24- cooperating with a lining 25 of special shape forming, with said joint 23, channels 26 for the flow of the circulating uid. The upper end of the lining 25 forms a cylinder 9 through which can slide a piston S carried by the solid shaft 27 of the turbine, while its lower constricted portion, which slants inwardly and downwardly, defines with the part providing the throttle 24 a venturi 28 which creates at 29 a lower pressure operative upon the lower face 67 of the piston 8, whereas the higher initial pressure P1 is operative upon its upper face 68. Here again the rotor structure of the turbine is subjected to the action of a downwardly directed differential pressure which adds itself to the gravitational thrust as exerted upon the rotor structure of the turbine.

In FIGS. 4 and 5 a const-ructional embodiment of the invention is shown related to a special turbine which is adapted to come into operation only incidental to the overcoming of a given load upon the drilling bit. In this form, the body portion 1 of the turbine is surmounted by a joint or union 31 of special shape which, in turn, carries another joint 32 provided with channels 33 for the flow of the circulating iiuid, the lower end of said joint being 4provided with an annular seat 34 which is held in position by a plate 35 and a screw 36. The turbine shaft 4 having a channel 5 as aforesaid has its mouth formed downwardly by channels, not shown, at a suita-ble position underneath the stack of rotor parts and is surmounted -by a mushroom-shaped throat member 37 whose upper face is fitted with a resilient gasket 38.

When the drilling bit is not loaded, the throat member 37 rests by its outer surface on the bulge or shoulder 39 formed by the joint 31. A narrow gap 40 is defined between the throat member 37 and the seat 34 for the circulating fluid which thus flows through the channel 5 in the shaft 4, but does not ilow through the stator and rotor stacks so that the turbine is inoperative. As soon as a suitable load is applied against the drilling bit, the

gasket 38 is applied against its seat 34, whereby the circulating fluid passes through the annular channel 41 which is then opened and flows through the blade set of the turbine. The chamber 42 dened inside the throat member 37 is then at the P2 pressure which prevails under the set of blades of the turbine and which acts upon the surface `69, while the pressure P1 prevails in the channels 41 and acts upon the surface 70. The thrust upon the shaft and rotor structure of the turbine carried by the bearing 62 is thus lessened by the difference Pl-Pg which corresponds to the pressure drop in the turbine as applied to the average cross sectional area of the gasket 38. This unloading permits the pressure exerted upon the axial bearings of the turbine to be reduced, thereby staving ot any risk of overload.

According to the other constructional modification shown by FIG. 6, the body portion 1 of the turbine is surmounted by a joint or union 44 into which is screwed a head 45 having channels 46 for the ilow of the circulating lluid and supporting a Sylphon bellows 47, the lower end of which is provided with a ring member 48 into which is rigidly set a sealing gasket 49. The hollow shaft 4 carries a revoluble plate 50 at its upper end which rests upon the gasket 49. The internal capacity of the Sylphon :bellows 47 communicates through the channel 5 in the shaft 4 with a position where a pressure P2 prevails and is situated underneath the set of blades of the turbine, said pressure acting upon the upper face 71 of the plate, while a pressure P1 exerts itself on the lower face 72 of the plate S0, thus generating an upwardly directed compensating pressure which increases the specilic power torque which operates on the drilling bit.

In the further constructional modification shown in FIG. 7, the body 1 of the turbine carries a tubular joint or union V52 rigid with a bell-shaped member 53 providing channels 54 for the flow of the circulating uid. A Sylphon bellows 55 is housed in the bell-shaped member 53. This bellows 5S is secured to the member 53 at its lower end and carries at its upper end a ring member 56 in which is anchored a joint or union S7. A plate 58 supported by the upper end of the turbine shaft 4 rests under sealed conditions on the joint 57. The chamber 59 defined by the member 53 outside the Sylphon bellows `55 communicates with the channel 5 in the shaft 4 by a nipple 60. The pressure prevailing in the chamber 59, and acting upon the face 73 of the plate, is equal to the pressure P2 which prevails underneath the set of blades of the turbine, while the pressure Pl which prevails over said set of blades is upwardly operative on the face 74 of the plate 58. The possibility is thus afforded to cause an upwardly directed unloading pressure to act upon the shaft.

Constructional details may be varied without departing from the scope of the following claims.

What is claimed is:

1. 'In a well-drilling turbine including a hollow, verti` cally disposed body portion, a stack of stator parts rigid with said body portion, a central shaft, a stack of rotor parts rigid with said shaft and operatively associated with said stator parts, means for providing a flow of power fluid downwardly to said stacks, and axial bearings rotatably supporting said shaft within said body portion: an upwardly open cylinder mounted stationarily in said body portion above said stacks and dening a chamber, a piston slidable in said cylinder, said piston having an upper face in contact with said power fluid above said stacks and a lower face, an opening provided in the bottom of said cylinder, said shaft protruding through said opening and being secured to said piston, an axial channel in said shaft, ports defined in said shaft establishing communication between said axial channel and the inner Space of said body portion under said stacks, and other ports defined in said shaft establishing communication between said axial channel and the cylinder chamber under said piston for transmitting to said piston lower face the pressure within said body portion under said stacks, thereby imparting an axial thrust to the shaft for modifying the specific torque of theturbine.

2. In a weil-drilling turbine including a hollow, vertically disposed body portion, a stack of stator parts rigid with said body portion, a central shaft, a stack of rotor parts rigid with said shaft and operatively associated with said stator parts, means for providing a flow of power fluid downwardly to said stacks, and axial bearings rotatably supporting said shaft within said body portion: a member forming an upwardly opened cylinder housed in said body portion above said stacks, a port defined in the lower end of said cylinder, a piston slida'ble in said cylinder, Said piston having an upper face in contact with the power fluid within said body portion above said stacks, said shaft being rigidly connected to said piston and extending through said port while providing an annular gap therewith, and a Venturi throat defined about said gap for creating a low fluid pressure transmitted to said piston lower face through said gap for applying an axial thrust to said shaft so as to alter the specific torque of the turbine.

3. A turbine according to claim 2, wherein the body portion has an -annular throttle adjacent said gap, the cylinder being limited at its lower end by an annular wall which slants inwardly and downwardly.

4. In a well-drilling turbine including a hollow, vertically disposed body portion, a stack of stator parts rigid with said body portion, a central shaft, a stack of rotor parts rigid with said shaft and operatively associated with said stator parts, means for providing a flow of power duid downwardly to said stacks, and axial bearings rotatably supporting said shaft within said body portion: an annular seat defined in the body portion of the turbine above said stacks, a mushroom-shaped member forming a piston fixed to said shaft, a gasket carried by said member for co-operating with said seat, an axial channel defined in said shaft and extending through said member, ports defined in said member establishing communication between said axial channel and the inner space of said body portion under said stacks and an annular lbulge formed on said body portion so as to provide 4an abutment for said member, said member extending through said bulge, said shaft being axially shiftable for moving said gasket off the seat or toward the seat, thereby creating in the closed position a difference of pressure applied against said mushroom-shaped member for exerting an axial thrust on the shaft to selectively alter the specific torque of the turbine.

5. In a well-drilling turbine including a hollow, vertically disposed body portion, a stack of stator parts rigid with said body portion, a central shaft, a stack of rotor parts rigid with said shaft and operatively associated with said stator parts, means for providing a flow of power fluid downwardly to said stacks, and axial bearings rotatably supporting -said shaft within said body portion: a bridge member secured in said body portion above said stacks, passages for the power fluid defined in said bridge member, a downwardly directed Sylphon bellows arranged on the lower face of said member, a gasket provided at the lower end of said Sylphon bellows, a plate secured to the upper end of the shaft and located under said Sylphon bellows, said plate having a lower face in contact with said power fluid above said stacks and an upper face, said upper face of the plate being in sealing contact with said gasket, an axial channel defined in said shaft and communicating with said Sylphon bellows, and ports defined in said shaft for connecting said channel with the body portion under said stacks for transmitting the pressure prevailing under said stacks to said plate upper face and for applying upon said shaft an axial thrust so as to alter the specific torque of the turbine.

6. In a well-drilling turbine including a hollow, vertically disposed body portion, a stack of stator parts rigid with said body portion, a central shaft, a stack of rotor parts rigid with said shaft and operatively associated wtih said stator parts, means for providing a flow of power fluid downwardly to said stacks, and axial bearings rotatably supporting said shaft within said body portion: a downwardly open cylinder securely held in said body portion above said stacks, a plate fixed to the upper end of said shaft and movable inside said cylinder, said plate having a lower face in contact with the power fluid above said stacks and an upper face, a Sylphon bellows interposed between an edge of said plate and the lower edge of said cylinder, an axial channel in said shaft communicating with the inner space of the cylinder above said plate, and ports defined in said shaft establishing communication between said axial channel and the inner space of said body portion under said stacks so as to apply the pressure prevailing under said stacks to said plate upper face for subjecting the shaft to an axial thrust in order to alter the specific torque of the turbine.

7. In a well-drilling turbine including a hollow, vertically disposed body portion, a stack of stator parts rigid with said body portion, a central shaft, an -axial channel defined in said shaft, a stack of rotor parts rigid with said Shaft and operatively associated with said stator parts, means for providing a flow of power fluid downwardly to said stacks, and axial 4bearings rotatably supporting said shaft within said `body portion: a piston having oppositely located active faces connected for joint axial motion with said shaft, means for establishing communication between one active face of said piston and high pressure fluid within the turbine |body situated above said stacks, said axial channel of the shaft being in communication with the low pressure iluid within the turbine body situated under said stacks and with the other active face of said piston so as to exert upon said shaft an axial thrust as to modify the specific torque of the turbine.

8. A well drilling turbine comprising, in combination, a tubular body portion, a stack of stator parts fixed within said body portion, a shaft within said body portion, axial thrust bearings within said body portion rotatably supporting said shaft, a stack of rotor parts aixed to said shaft operatively associated with said stator parts, means for providing a flow of pressurized fluid to said stacks, means creating high and low fluid pressures at predetermined locations within said body portion directly proportional to the rate of uncontaminated fluid flow within and through said body portion, a piston member affixed to said shaft having first and second oppositely disposed pressure faces substantially transversely related to the axis of said shaft, means establishing communication between said first face and said high fluid pressure and means entirely within the tubular tbody portion establishing cornmunication between said second face and said low uid pressure so as to exert an axial thrust upon said shaft to control and modify the turbine characteristics during operation.

9. A well drilling turbine comprising, in combination, a tubular body portion, a stack of stator parts :fixed within said lbody portion, a shaft within said `body portion, axial thrust bearings within said body portion rotatably supporting said shaft, a stack of rotor parts aixed to said shaft operatively associated with said stator parts and deining a passageway within said body portion having an inlet and an outlet, means for providing a ow of pressurized fluid to the inlet of said stacks and through said body portion, a cylinder concentrically iixed within said body portion, a piston fixed to said shaft slidingly and sealingly received Within said cylinder, rst and second pressure faces deiined on said piston in opposed relation, means establishing communication between said rst piston face and the fluid pressure at said passageway inlet, and means entirely within the tubular body portion establishing communication between said second piston face and the uid pressure at said outlet and Within the tubular lbody portion.

10. In a well drilling turbine as in claim 9 wherein said cylinder is in the form of a cup fixed to said body portion adjacent the inlet of said stacks and having an open end facing said stacks, said piston being defined on an 8" v end of said shaft, and said means communicating said outlet pressure with said second Aface including a passage deiined in said shaft having a rst port intersecting the piston end of said shaft and communicating with the closed chamber deiined by said piston and cylinder, and a second port deiined in said shaft establishing communication with said passage and the outlet ftiuid pressure.

1l. In a well drilling turbine as in claim 10 wherein said rst port comprises a nozzle of restricted Sectional area.

References Cited in the tile of this patent UNITED STATES PATENTS 1,273,913 Ostenberg July 30, 1918 1,482,702 Scharpenberg Feb. 5, 1924 2,321,875 Temple June 1S, 1943 2,591,488 Yost Apr. 1, 1952 2,592,519 Postlewaite Apr. 8, 1952 2,657,535 Levy Nov. 3, 1953 2,710,234 Hansen June 7, 1955 2,760,832 Bidwell Aug. 28, 1956 2,932,281 Moskowitz Apr. 12, 1960 FOREIGN PATENTS 762,749 Great Britain Dec. 5, 1956 770,347 Great Britain Mar. 20, 1957

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