US2983481A - Motors for subterranean drilling - Google Patents

Description

y 1961 w. TIRASPOLSKY ETAL 2,983,481

MOTORS FOR SUBTERRANEAN DRILLING Filed Feb. 27, 1958 2 Sheets-Sheet 1 Meomrk lrnnspusn y 9, 1961 w. TIRASPOLSKY ETAl. 2,983,481

MOTORS FOR SUBTERRANEAN DRILLING Filed Feb. 2'7, 1958 2 Sheets-Sheet 2 &

MOTORS non SUBTERRANEAN DRILLING Wladimir Tiraspolsky, 69 Ave. Victor Cresson, Issy-les- Moulineaux, France; Roger Francois Rouviere, Castor,

- Lot 24, Aureilhan, France; and Jean Chare, Chernin dUrac, Tarbes, France Filed Feb, 27, 1958, Ser. No. 717,970

Claims priority, application France Mar. 1, 1957 5 Claims. (Cl. 253-3) The present invention relates generally to drilling motors for subterranean or underground work of the hydraulic, electric or other type and relates more particularly to hydraulic motors such as drilling turbines like those which are now commonly used for the exploitation of oil fields.

The service duration of drilling motors for subterranean work is determined to a large extent by the wearing rate of the axial abutments which take either the thrust that inherently comes from the operation of the machine .(weight of rotor and hydraulic thrust in turbines) or the thrust from the drilling tool on the ground or alternatively the algebraic sum of these two typical thrusts.

As is known by technicians skilled in the art, the possibility exists for the wearing rate of the aforesaid abutments, to be reduced, particularly where they are lubricated by the power fluid itself by increasing the delivery rate of the liquid which flows through the abutment for cooling the same and for lubricating the contacting surfaces. Such an influence is particularly marked when dealing with abutrnents having abutment surfaces such as rubber-lined abutments or abutments of an equivalent type as used in modern drilling turbines and in electric motors.

In subterranean motors and particularly in drilling turbines, the several parts of the abutment are immersed in the circulating fluid so as to irrigate to the utmost the sliding surfaces.

An object of the invention is to provide an improved motor for subterranean or underground work adapted to increase and to adjust to a suitable value the irrigation degree of axial abutments or thrust bearings, thereby lessening their wearing rate and increasing the service duration of the motor between two replacements of such bearings.

As the thrust bearings are made up of a sequence of stationary parts operatively connected to the stator structure and separated by movable parts or discs involved in the rotor structure, the main stream of circulating fluid flows through a sequence of channels of two different types.

Another object of the invention is to provide a drilling motor for subterranean work in which the sectional area of the stator and/or rotor channels in the abutments or thrust bearings varies adjacent to a stage. Said channels being operatively connected with the contact surfaces on the bearings, the sectional variation or variations of the channels as an abutment stage is passed create between the two faces of a part (for example the stator) around which theirrigation stream derived from the main stream may flow or between the downstream and upstream sides (or conversely) of two sequential stages such a pressure differential as will tend to enhance the strength of the fluid stream which irrigates the bearing elements.

The possibility is therefore afforded to adjust the.

PatentedMay 9, 1961 strength of the deviated irrigation stream by a suitable regulating device.

The reduction of sectional area achieved for example between the inlet and the outlet of the channel or channels in the stationary part of each of the abutment stages thus causes, for a predetermined fluid delivery rate, a reduction of pressure from the upstream side to the downstream side, thereby causing a stronger flow of the circulating fluid inwardly of the abutment for irrigating the bearing surfaces.

The possibility thus exists for a preset fluid delivery rate to modify the extent of the pressure differential by influencing the extent of sectional reduction of the channels between their inlet and their outlet in the stationary parts of the abutment.

A further object of the invention is to provide a drilling motor for subterranean work as aforesaid in which each of the stationary parts is adapted or arranged for selectively altering the sectional reduction of the channels between their inlet end and their outlet end.

A still further object of the invention is to provide a motor as aforesaid wherein the sectional reduction may be obtained by suitably outlining the channels through which the. circulating fluid flows opposite to the abutment stages, for example by inclining with respect to verticality at least one of the walls which define each channel for imparting the same a tapering shape. inlet ends of said channels may be suitably outlined.

Still a further object of the invention is to provide a motor as hereinbefore set forth in which according to Bernouillis theorem partial recovery of the energy as absorbed by the sectional reduction may be obtained by alternating channel sections of decreasing cross sectional area situated in the stationary parts and channel sections of growing cross sectional area which may be advantageously arranged between the'downstream side face of an abutment stage and the upstream side face of the following stage somewhat in venturi fashion.

Contrary to what is provided in existing abutments, the present abutments provided in the improved motor for subterranean work may be advantageously arranged asymmetrically in the axial direction. It is desirable for said lack of symmetry to be so increased as to render it truly apparent, thereby obviating any risk of abutment inversion as the abutments are being erected when dealing with abutments having circulating channels whose cross sectional area gradually becomes smaller. Such an increase of asymmetry permits the structure to be improved in some respects instead of curtailing its operational qualities. Thus the possibility of shifting the equatorial plane of the actual abutment element with respect to the middle of the height of the outer body of said abutment permits the same to be more suitably adapted in some cases to the mounting dimensions of subterranean turbines or motors, thereby simplifying their erection. Furthermore this asymmetry permits asymmetrical circulating channels to be provided in the surface of the elastic shoe elements of the rubber type, each shoe element having a round leading edge which is highly favorable to the penetration of a liquid film between the contacting surfaces and a trailing edge which be of sharp outline while also permitting the useful bearing surface of the elementary shoe elements defined by the radially extending circulating channels to, be increased.

With these and such other objects in view as will incidentally appear hereafter, the invention comprises the novel construction and combination of parts thatwill now be described in detail with reference to the accompanying diagrammatic drawings illustrating the same and forming a part of the present disclosure.

Alternatively the 3 In the drawings: Figure 1 is a diagrammatic sectional elevational view of a portion of a drilling turbine, the section being efiected in the region of the axial abutment.

Figure 2 is across sectional view on the line II-1I of Fig. 1.

Figure 3 is a detail sectional view drawn to a. larger scale :on the line IIIIII of Fig. 2.

Figure 4 is a view similar to Fig. 1 relating to a constructional modification.

In the showing of Fig. 1, the body 1 of the turbine carries on its inner face a stack of annular or skirt parts 2 with which abutment discs 3 are rigidly connected, said discs being provided with rubber or like shoe members 4, 5. The turbine shaft 6 is fitted as usual with movable discs 7 separated by bracing ring members 8.

According to the invention, the flow channels or passages'9 defined between the abutment discs 3 have (as illustrated) a gradually decreasing cross sectional area which results from the fact that the inner wall of each channel 9 is outwardly inclined for imparting to the corresponding part of the abutment disc a frustoconical shape i.e. for procuring convergence of the opposite faces of each channel 9. Owing to this arrangement, a pressure drop is obtained between points situated on the upstream side and on the downstream side respectively of the abutment stage being considered, thereby facilitating fluid flow inside the abutment itself.

In such an abutment, the pressure drop is substantially governed by a kinetic law expressed by the following equation:

i i S S in which Q designates the fluid delivery rate, and S and S respectively designate the inlet and outlet sectional areas of the abutment channels. All other factors being assumed to be equal, the delivery rate through the abutment will be of the following form:

. I 1 mi abut-K (2( It will be seen from the foregoing that the possibility remains for the value of the abutment-irrigating delivery rate to be selected in a wide range. As the rotational speed of the movable discs is itself proportional to the delivery rate Q, the intensity of irrigation per revolution will remain substantially constant for a predetermined axial position of the abutment.

The rubber shoe members 4, are constituted by propecting elements separated by radial channels or passages 19 through which the circulating fluid flows. The fluid also flows through a gap 11 defined between the inner peripheral face of the abutment seats 3 and the outer peripheral face of the ring members 8. Consequently the irrigation fluid flows through said abutments along the channels in the shoe members 4, the gaps l1 and the channels 210 in the shoe members 5 and then merges with the main circulating stream.

As illustrated in Fig. 3, the outline of the channels considered in a plane tangent to a circumference whose centre is the axis of the shaft 6 shows that each elementary rubber shoe member 4 has a curved leading edge 12 and a sharp trailing edge 13, thereby facilitating the drive of the circulating fluid by the movable disc 7 which are revolved in the direction indicated by the arrow in Fig. 3

ber 3 which carries the rubber shoe members 4,. 5. is.

upwardly offset with respect to the centre transverse plane of the skirt portion 2. Such asymmetry facilitates erection as previously stated.

The constructional modification shown in Fig. 4 is similar to the construction represented in Fig. 1. How ever the movable discs 7 carried by the turbine rotor shaft 6 have a downwardly convergent frustoconical shape so that the fluid circulating channel 14 defined adjacent each disc 7 has a flaring shape, thereby partly compensating for the loss of energy which occurs in the channels 9 formed adjacent each abutment stage. Moreover the rubber shoe members 4, 5 are interconnected by a rubber lining 15 arranged opposite the periphery of the ring members 8. Here again the pressure reduction between the'upstream side'and the downstream side of an abutment stage due to the progressive reduction of sectional area of the channels 9 facilitates the irrigation of the abutment.

Minor constructional details may be varied without departing from the scope of the subjoined claims.

What is claimed is:

l. A subterranean turbine drilling device comprising, in combination, a casing, a shaft substantially concentrically supported within said casing for relative rotation thereto, casing supported bearing members concentrically located within said casing, shaft supported bearing members in axial alignment with said casing supported bearing members, bearing means interposed between said casing and shaft supported bearing members having radial extending passages adjacent one of said members, said casing and shaft supported bearing members and said casing defining a primary flow path for the turbine actuating fluid, a secondary fluid flow path through said bearing means passages and said casing supported bearing members and fluid flow path restriction means defined by said casing supported bearing members whereby a portion of said fluid within said primary flow path is diverted into said secondary flow path through said bearing means for the lubrication thereof.

2. In a subterranean turbine drilling device, a casing, a shaft rotatably supported in said casing, a thrust bearing disc aflixed to said shaft adjacent thereto, a thrust abutment disc aflixed to said casing adjacent said bearing disc in axial alignment therewith, a passageway defined between said abutment disc and said casing for the turbine actuating fluid, bearing means interposed between said discs adjacent said shaft having radial extending passages adjacent the relative rotating surfaces thereof, an axial extending passage within said abutment disc between said bearing means and said shaft, said passage establishing communication between the upstream and downstream sides of said abutment disc, and flow restriction means in said passageway creating a higher fluid pressure on the upstream side of said abutment disc than on downstream side diverting a portion of the turbine actuating fluid through said passage and bearing means.

3. In a subterranean turbine drilling device as in claim 2 wherein said flow restriction means comprises converging wall portions, with respect to the flow of turbine actuating fluid, defined on said abutment disc forming said passageway.

4. In a subterranean turbine drilling device as in claim 3 wherein the periphery of said thrust bearing disc is formed with a diverging surface with respect to the flow of turbine actuating fluid.

5. In a subterranean turbine drilling device as in claim 2 wherein said bearing means radial extending passages are formed with a sharply defined trailing edge and a rounded leading edge with respectto the relative rotative movement of said bearing means and the adjacent disc.

References Cited in the file of this patent UNITED STATES PATENTS

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