US1675325A

US1675325A - Hydraulic underreamer

Info

Publication number: US1675325A
Application number: US84342A
Authority: US
Inventors: Benjamin F Blanchard
Original assignee: Individual
Current assignee: Individual
Priority date: 1926-01-28
Filing date: 1926-01-28
Publication date: 1928-07-03
Anticipated expiration: 1945-07-03

Description

July 3, 1928.

Filed Jan. 28, 1926 2 Shee'ts-Sheet l Patented July 3, 192s.

UNITED STATES PATENT oFFlcE.

HYDRAULIC UNDEBBEAME?. I

Appnauon nica January 2s, 192s. serial m. 114,342.

This invention relates to improvements in hydraulic rotary underreamers used 1n well drilling, and may be considered as an improvement over the underreamer dlsclosed in my prior Patent, No. 1,548,578, lssued August 4, 1925.

An object of this invention is to prov1de an improved hydraulicallyloperated underreamer which is of improved construction and which is so designed that it is very diliicult for parts to get out of order.

Another object of this invention is to provide an improved cutter construction upon an underreamer.

A further object of this invention is to provide an improved mechanism for admitting fluid to the interior of the lower pipe or drill pipe above the tool, so that pressure will not build up within the tool during lowering to cause the reamerto be expanded when itis not so intended.

With the foregoing and other objects in view which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanyin drawings for an illustrative embodiment o the invention, wherein:

Figure l is a vertical section through the improved underreamer shown in fully expanded position,

Fig. 2 is a view similar to Fig. 1, illustrating the reamer in fully contracted position.

Fig.4 3 is a partial 'View in section illustrating the details of construction of the cutters and blocks on which the cutters are mounted, thev reamer in this view being shown in fully expanded position,

Fig. 4 is a partial view in side elevation taken substantially in the direction of the arrow 4 upon Fig. 3,

Fi 5 is a.' horizontal section taken substantlally on the line 5-5 of Fig. 3,

Fig. 6 is a view similar to Fig. 5 illustrating the reamer in contracted position, and may be considered as a horizontal section taken upon the line 6-6 of Fig. 2,

Fig. 7 is a vertical section illustrating the details of construction of the valve and Referring to the accompanying drawings wherein similar reference characters desig.

ports which admit fluid to the interior of" nate similar parts throughout, the-details of construction of the reamer proper are as follows: The reamer consists of a cylindrical body 10 having an interior cylindrical surface. In this body there are formed two diametrical slots 11, and within it there is positioned a conical wedge or mandrel 12, in which is formed a longitudinal bore 13. This wedge is threadedlyconnected to the body 10, as indicated at 14, and constitutes a wash pipe terminating inl a cylindrical section 15. Blocks 16 are vertically slidable in the two slots 11. These blocks have their inner faces engageable upon the conical wedge or mandrel l12 so that when they are lifted, they will `be expanded or forced radially outwardly through the slots 11. Each of the blocks' has its inner face presenting a conical surface which is complementary to the conical surface on the wedge 12 when the blocks are in their uppermost position. They are also provided with lateral wings 17 whlch extend laterally beyond the sides of the slots 11, and these lateral wings have their forward surfaces cylindrical in shape so that they will lit against the interior cylindricalsurface of the body l0 when the blocks are in their uppermost position. In each of the blocks there is positioned a vertical pin 18 which is locked in place as by a pin 19, and a cutter or reamer 20 is rotatabl mounted upon each pin 18. A bore 21 is ormed in each block 16 so that a spike or punch can be inserted therein to knock loose the vertical pin 18 whenever it is desired to replace the cutters 20 or to replace the pins 18.

Adjacent the lower end of each of the blocks 16 there is formed a downwardly and inwardly inclined pin 22 which is threaded.

A bushing 23 is threaded onto this pin and a cutter 24 is rotatably mounted on this bushing between washers 25. Each of the cutters 24, because of the above described construction, is rotatable about axes which are upwardly and outwardly inclined. They are so formed as to provide a surface 26 which on the lower portion of the cutter is approximatelyl vertical, and also a 4surface 27 which on the lower portion of the cutter is approximately horizontal. It will be understood that these cutters do the major portion of the cutting, the cutters 20 being used mainly for merely smoothing up the hole thus reamed.

Supplemental blocks 28 are secured to the pins 22 as by cap screws 29, and these-blocks are similar in cross section to the bloclis 16 in that the have the lateraljwings 17. The length of the slots 11 is approximately twice the overall dimension of the'blocks 16 -to- 5 get-her with the supplemental blocks 28.

` within the slots 11, a cylindrical AAs a means for raising the blocks 16 together with the' supplemental blocks 28 is slidable within the body below t e blocks l and arranged about-the .conical wedge or mandrel 12. This piston is illustrated as `being provided with a cup or packing leather 31 held in place by a ring 32 which is fastened by screws 33. On the interior of the l body there is positioned a brass or bronze Wedge 12, when the pistoni-$0 is in'ts upper-- liner 34 against which the packing leather 31 bears. The interiorof the piston 30 has a conical surface which is complementary to the conical surface of the mandrel or conical most position, that is, when)y it hasflifted the blocks 16 to that position` in which encounter the upper ends of theslots 11. In the lower end o the bodylO there is screwed 25, a sub 35 having a division web or a blanked 30 through, but at the same time causing wardly through the bore 13, the pressure drei 12, win@ developed within the body`10 will cause the piston-30 to rise and thus lift the blocks 16. It will be noted that when the blocks are completely lifted their upper ends engage the tops 'of the slots 11the forward surfaces of the wings 17 engage the interior surface of the body while the inner surfaces of the blocks 16 engage and t the conical wedge 12 and also the piston 30 fits the conical wedge 12, thus forming a tight, rigidi construction during the reaming so'that there will be no wobbling or loosening of the parts.

On lowering theunderreamer into the hole by the drill pipe D it will be understood that the well hole is fullof liquid and it will flow upwardly through the fbores 37 in the 'blanked off ortion 36 of the sub 35. Be-

cause of the act that a quick lowering ofthe reamer into the hole might cause this uid to.build up a pressure on the under side of the piston 30, causing the reamer to be expanded during the lowering, there is provided a particular valve construction at the upper end of the reamer which will admit fluid from the hole intothe drill pipe D to eliminate this.

In the bodyl of the conical wedge orinanextends above the cylindrical body 10,there' are formed a plurality of radial Aports 38, and on its interior there is iston 30 they' formed an annular recess 39 with which the ports communicate. On theinterior of the upper end of the conical wedge or mandrel 12 there is screwed a valve seat 40 having a vertical `bore 41 therethrough and providing a seat for the ball check valve 42. The ball check valve 42 is maintained adjacent its seat by a cage 43. The lower end of the bore 41 is closed by a plug 44,. and in the body 0f the valve seat 40 there are formed radial ports 45 which communicate with the recess 39. As clearly indicated in Fig. 8,

vertical passages 46 are formed in the body..

of the fluid will be caused to lill the drill pipe D b flowing throu h the ports 38 into the annu ar recess 39 and through the ports 45, fiowing upwardly through the bore 41 beneath the check valve 42. After the device vhas been lowered into the well, fluidis forced downwardly within the drill pipe, the check valve 42 again seats and the fluid is all caused to-flow through the vertical passages 46. In. this manner it will be noted that fluid can enter the drill pipe D above the tool so that no pressure will be developed on the under side of the piston 30, causing it to be lifted during the lowering into the well hole.

From the above described construction it will be appreciated that anV improved hydraulically operated underreamer is provided which issimple in construction and very rugged in design. Furthermore, when the reamer is in expanded position, all parts will be snugly fittin or resting against each owever, on lowering the reamer into the well, fluid may fiow upwardly within thepassages 37, but the larger portionv other, forming a so id structure duringthe" reaminv. c c

It will be understood that variousI changes may be made in the detail of construction without departing from the spirit or scope of the invention as defined b the a ded l y y Iclaim:

- 1. An underreamer comprising a slotted' ally be ond the sides of the slots between 'the w and thebody, a Vpiston within the body below said blocks,r and means for causing fluid discharged through said Wedge to build up a pressure beneath said piston, causing itv to lift said blocks into engagement with said wedge, so that they will be expanded thereby.

l2. An underreamer comprising a slotted body presenting an interior cylindrical surface, a conical wedge having a bore therethrough disposed in said body, blocks carrying cutters slidable in said slots having their inner sides en agea'ble upon the wedge, a piston Vdisposedg within the body and about the lower end of said wedge, said piston being arranged below said locks, and means for causing fluid discharged through said wedge to buildup a pressure beneath said piston, causing it to `lift said bloclis into engagement with said wedge, so that they will be expanded thereby.

3. An underreamer comprising a slotted body presenting an interior cylindrical surface, a conical wedge having a bore theretlirough disposed in said body, blocks carrying cutters slidable in said slots having their c 'i inner sides engageable upon`the wedge, a

wedge to build upa.

piston disposed within the body and about the lower end of said Wedge, sald piston being arranged below said blocks, and means for causing fluid discharged through said ressure beneath said piston, causing it to li said blocks into engagement with said wedge, so that they will be expanded thereby, sald blocks having lateral wings extending laterally beyond the iddes of the slots between the Wedge and the i 4.yAn underreamer comprising a slotted body-presenting an interior cylindrical surface, a conical wedge having a bore therethrough disposed in said body, blocks carrying cutters slidable in said slots having their inner sides engageable upon the wedge, said blocks having lateral wings extending laterally be ond the sides of the slots between the wedge and the body, a piston disposed Within the body below said blocks, and means for causing fluid discharged through said wedge to build up a pressure beneath said piston, causing it to lift said blocks into engagement wlth said wedge, so that they will be expanded thereby, said piston having a conical bore therein complemenv tary tothe surface of the wedge.

5. An underreamer comprising `a slotted, hollow body, a Wedge disposed in said body, blocks carr ing cutters slidable in the slots, said blocks eing engageable upon said wedge so as to be expanded thereby and carrying lateral wings in sliding en agement with the inner circumference o the body to prevent the blocks from being withdrawn from the slots, apiston slidable in `the body below the blocks, said wedge havving a bore therethrough through which fluid may be discharged, and means for causing the fluid discharged through said wedge to build up a pressure below the piston to cause the piston to lift the blocks into engagethrough the valve'. seat for the purpose described.

7. In a hydraulically operated well` drilling tool, a tubular body through which fluid is adapted to be forced, a valve seat mounted in said body, a Valve adapted to seat thereon, means closing the bottom of the valve seat, there being passages formed in the tubular body and in the valve seat establishing communication between the exterior of the body and the interior of the valve seat above said closing means, there being passages formed in the valve seat forming by-passes about the valve permitting fluid to be forced through the valve seat Within said tubular body.

In testimony whereof I have signed my name to this specification.

B. F. BLANCHARD.

below the valve and passages arranged-