US2751022A

US2751022A - Apparatus for allowing well conduits to fill with well bore fluid

Info

Publication number: US2751022A
Authority: US
Inventors: Reuben C Baker; Martin B Conrad
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1951-12-14
Filing date: 1951-12-14
Publication date: 1956-06-19
Anticipated expiration: 1973-06-19

Description

June 19, 1956 R. c. BAKER Er Ax. 2,751,022

APPARATUS FOR ALLOWING WELL CONDUITS TO FILL WITH WELL BORE FLUID Filed Dec. 14, 1951 4 sheets-sheet 1 by m www

INVENTORS. REL/BEN C. BAKE/e, MAeT/N B. CoA/@A0, BY

r roe/VE YS June 19, 1956 R. C. BAKER El AL APPARATUS FOR ALLOWING WELL CONDUITS TO FILI.. WITH WELL BORE FLUID Filed Dec. 14 1951 4 Sheets-Sheet 2 l jg INVENTORS.

REL/BEN C. BA1/ 52,

MAevT//v B. Cave/4o,

June 19, 1956 R. c. BAKER Er AL 2,751,022

APPARATUS FOR 'ALLOWING WELL CONDUITS TO FILL WITH WELL BORE FLUID l Filed Dec. 14, 1951 4 sheets-sheet s v2/2, a pi?. .9.

INVENTORS. EUE/v C. .3A/aie, B MART/v B. CONRAD,

rroe/vsys June 19, 1956 R. c. BAKER Er AL 2,751,022

APPARATUS F OR ALLOWING WELL GONDUITS TO FILL WITH WELL BORE FLUID Filed oec. 14, 1951 4 sheets-.sheet 4 JNVENToRs. REL/BEN C. BAKEQ, MAQr//v B. CoA/@A0,

Erma/.JMW

United States Patent O APPARATUS FOR ALLOWING WELL CONDUITS T FILL WITH WELL BORE FLUID Reuben C. Baker, Coalinga, and Martin B. Conrad, Downey, Calif., assignors to Baker Oil Tools, Inc., Los Angeles, Calif., a corporation of California Application December 14, 1951, Serial No. 261,639

19 Claims. (Cl. 166-225) The present invention relates to subsurface well apparatus, and more particularly to apparatus that will allow a well casing string, or other well conduit, to automatically fill with iiuid as it is lowered in a well bore.

Back pressure valve devices are incorporated in subsurface well casing to prevent return iiow of cement slurry, and other iluent substances, into the casing after having been ejected therefrom. Such back pressure valve devices prevent upward liow of fluids into the casing, and, if allowed to close when the casing is being run in the well bore, maintain the casing in an empty state, causing the casing to be buoyed or iioated by the well bore iluid to a certain extent. lf such an empty casing is run to a comparatively great depth in a well bore filled with liquid, the hydrostatic head of liuid externally of the casing is of such great extent as to tend to collapse the lowermost portion of the casing inwardly. this occurrence, it has been the practice to at least partially iill the casing from the top of the well bore, to reduce the pressure differential acting on the lower por- To guard against tion of the casing, all of which is a time consuming and costly operation.

Accordingly, it is an object of the present invention to provide improved apparatus enabling the casing string to till automatically with the well bore fluid as it is being lowered in the well bore, while still providing a back pressure valve device preventing return flow of fluids into the casing string after they have been forced through the device.

Another object of the invention is to provide apparatus adapted to be incorporated in a well casing string, which contains a back pressure valve and in which the latter is held positively in ineffective and open position while the casing string is being lowered in the well bore until purposely released.

A further object of the invention is to provide apparatus to be incorporated in a well casing string and embodying a back pressure valve which is positively held off its seat while running the casing string in the well bore, allowing the casing string to lill with the well bore fluid, in which the valve can be hydraulically and positively released to permit its engagement with its companion seat whenever desired.

This invention possesses many otheradvantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which it may be embodied. Such forms are shown in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section through one form of apparatus embodying the invention, attached to a sec- .tion of well casing, and with the parts in one relative n 2,751,022 Patented June 19, 19.56v

position allowing well fluid to ilow upwardly through the device and into the casing sections thereabove;

Fig. 2 is a longitudinal section through the lower portion of the apparatus disclosed in Fig. 1, with certain of the parts in position to release the back pressure valve member;

Fig. 3 is a partial longitudinal section similar to Fig l, disclosing the back pressure valve released;

Fig. 4 is a cross-section taken along the line 4 4 on Fig. 3;

Fig. 5 is a View similar to Fig. l of another embodiment of the invention, with the back pressure valve held in open position;

Fig. 6 is a view similar to Fig. 5 illustrating the back pressure valve in released position, enabling it to close;

Fig. 7 is a cross-section taken along the line 7--7 on Fig. 6;

Fig. 8 is a longitudinal section through still another embodiment of the invention;

Fig. 9 is a partial longitudinal section, on an enlarged scale, of the device shown in Fig. 8, with certain parts shifted to a position in which the back pressure valve can be released;

Fig. 10 is a longitudinal section similar to Fig. 8, with the back pressure valve shown in released position;

Fig. 1l is a cross-section taken along the line 11-11 on Fig. 9;

Fig. 12 is a longitudinal section through still another embodiment of the invention, with the back pressure valve held in open position;

Fig. 13 is a fragmentary longitudinal section with the parts in position to release the back pressure valve;

Fig. 14 is a view similar to Fig. 12, illustrating the back pressure valve released;

Fig. 1S is a cross-section, on an enlarged scale, taken along the line 15-15 on Fig. l2.

The apparatus illustrated in the drawings is adapted to form part of a casing string and can be either in the form of a casing shoe or collar. It embodies an upwardly seating back pressure valve device for preventing upward passage of uids through the apparatus and into the well casing. Such upward seating is initially prevented, during running or lowering of the casing in the well bore to allow the fluid in the latter to iiow into the casing. After the casing string has been run in the well bore to the desired depth, pressure can be applied to the iluid within the well casing, to effect hydraulic release of the upwardly seating member, permitting it to seat. Thereafter, fluids can be pumped down through the well casing and through the apparatus, but return iow of such iiuids is prevented by the back pressure valve.

In the form of invention illustrated in Figs. l to 4, inclusive, the apparatus is disclosed as a casing shoe A forming the terminal portion of a string of well casing B that can extend to the top of the well bore. The casing shoe includes a tubular member 10 having an upper threaded box 11 which can be screwed onto the lower end of an adjacent casing section B. This tubular member has a plurality of longitudinally spaced internal grooves 12 therein to receive the external flanges or circumferential ribs 13 of a cementitious plug 14 that is cast in the tubular member. r[he lower end 15 of this plug extends below the tubular member 1i) and is rounded to form a guiding nose, for the purpose of facilitating lowering of the casing shoe, and the casing itself, past restrictions or minor obstructions in the well bore.

The casing shoe A has a central passage 16 therethrough. This passage extends through the upper portion of the cementitious plug 14 as well as through a centrally disposed valve seat 17 that is cast in the plug. This valve seat carries a valve seal ring 18 of rubber, or rubber-like material, engageable by an upwardly seating check or back pressure valve member 19, which may be in the form of a ball that is preferably buoyant in cement slurry. This ball is contained within the upper portion of a valve housing 21, which extends into the valve seat 17 to clamp the valve seal ring 18 between the seat and the upper housing portion. This upper housing portion 2t) is piloted within an intermediate housing portion 22 having a generally cylindrical bore 23. The intermediate valve housing portion is provided with a plurality of longitudinally spaced circular grooves 24 in which ribs 25 of the cementitious plug 14 are cast, to secure the intermediate housing portion 22 to the plug 14.

The lower end 26 of the intermediate housing portion 22 engages the upper end 27 of a lower valve housing portion 28, having a cylindrical bore 29 therethrough. This lower housing portion 28 is also provided with longitudinally spaced circular grooves 30 in its exterior into .which ribs 31 of the cementitious plug 14 are cast, to rmly anchor the lower portion to the plug.

The ball valve member 19 normally tends to move upwardly when fluid moves upwardly through the

valve housing portions

28, 22, Ztl, to engage the valve seat 17 and its seal ring 18, and preclude upward flow of luid into the well casing sections B above the shoe A. When fluid is pumped downwardly through the casing string B, it will shift the valve member 19 in a downward direction from its seat 17 to open position, such downward movement being limited by engagement of the ball member 19 with circumferentially spaced lugs or ribs 32 integral with and extending inwardly from the upper valve housing portion 2t). Fluid pumped down through the casing sections B will pass through the upper passage portions 16 and the valve seat 17, ilowing around the ball valve 19, and through the spaces between the lugs 32, to continue downward movement through the shoe for discharge from the lower end of the latter.

When lowering the string of casing B, including the shoe A, through fluid in the well bore, it is desired to allow the well iluid to flow upwardly through the shoe and into the casing sections thereabove. To enable this to occur, the ball valve member 19 is prevented from moving upwardly into engagement with its seat 17. As disclosed in the drawings, a valve stem 33 has a threaded upper end 34 screwed into a companion hole in the ball member, the valve stem extending downwardly into the intermediate and

lower housing sections

22, 28. The valve steml 33, and the ball valve member 19 attached thereto, are held in a lower position, with the ball valve member resting upon the supporting ribs 32, by a lower valve disc or member'35 having a hub portion 36 through which the valve stem extends, the valve disc 35 being secured to the stem by frangible means, which may take the form of a shear screw 37 threaded transversely through the hub 36 and into the stem 33. When the ball valve member 19 engages the ribs 32, and with the shear screw 37 intact, a peripheral ange 38 on the lower valve disc 35 engages the lower end, or inwardly directed ange 39, of the intermediate valve housing 22, the ange 38 being slidably engageable with the wall 29 of the lower housing portion 28. By virtue of engagement of the valve member flange 38 with the lower end of the intermediate valve housing 22, and because of the shear screw 37, the valve stem 33 and the ball 19 connected thereto are prevented from moving in an upward direction, to preclude engagement of the ball valve member 19 with its companion valve seat 17.

The lower valve disc member 35 has arcuate, circumferentially spaced ports or passages 40 extending longitudinally therethrough. As disclosed, the passages are equi-angularly spaced from one another and are separated by upper partitions 4l interconnecting the outer and

hub portions

42, 37 of the valve disc member. For purposes of strength, the inner and outer portions may also be interconnected by radially extending ribs 43. Ther upper portion 44 of the disc extends substantially vabove the shoulder 45 of the internal ilange 39 of the intermediate valve housing portion 22, for a purpose to be described.

Fluids can ilow upwardly through the valve disc ports 40, passing into the intermediate valve housing portion 22, and through circumferentially spaced arcuate passages or ports 46 in an upper Vvalve member or disc 47 that is slidably mounted on the valve stem 33. This upper valve member 47 has a hub portion 4S provided with a bore 49 that is non-circular in crossesection, being disclosed in the drawings as of square cross-section, the valve stem 33 also having a non-circular or square cross-sec` tion conforming to the hub bore cross-section. Similiarly, the bore 56 throughV the lower disc hub portion 37 may have a non-circular or square cross-section, conforming to the square section of the valve stem 33.

The upper valve disc member 47 is slidable longitudinally along the valve stem 33, its upward movement being limited by engagement of its flange or rim 51 with a shoulder 52 provided by vthe lower end of the upper valve housing portion 20. The upper valve member 47 may be moved downwardly along the valve stem 33 into engagement with the -lower valve member 35, as described hereinbelow.

The upper valve member has its passages or ports 46 staggered with respect to the passages or ports 4t) in the lower valve member. As a matter of fact, the upper valve member ports 46 are inl alignment with the partitions 41 of the lower valve member, and partitions 53 of the upper valve member 47, between its ports 46, are in alignment with the ports-40 in the lower valve member 35, the partitions in each member being sumcient to cover the ports in the other member. Radial strengthening ribs 54 may also be provided in the upper member 47, eX- tending between its hub 48 and rim 51.

When the shear screw 37 is intact, and the iiange 38 of the lower valve member 35 engages the stop shoulder 39 on the intermediate housing portion 22, the ball valve member 19 is prevented from moving upwardly into engagement with its seat 17. During lowering of the casing string B through the fluid in the well bore, such fluid can ow upwardly through the passages 4i) of the lower valve member into the intermediate housing portion 22, continuing up through the ports 46 in the upper valve member 47 into the upper valve housing portion 2i), owing between the supporting ribs or lugs 32 and around the ball valve 19 for continued upward movement through the Valve seat 17 and passage 16 through the cementitious plug into the upper casing sections B.

vWhen the casing has been run in the well bore to the desired depth, it will have been lilled automatically with the well yiluid. Thereafter, it is desired to tree the back pressure valve member 19, to permit its upward movement into engagement with the seat ll7. Fluids in the well casing may now be pumped in a downward direction, such movement of iluid carrying the upper valve disc 47 downwardly along the'valve stem 33 and the cylindrical wall 23 of the intermediate housing section 22 into engagement with the upper end 44 of the lower valve member 35, which position is illustrated in Fig. 2. The noncircular cross-sections of the valve stem 33 and the upper Valve disc bore 49 will maintain the passages of one member in alignment with the partitions in the other valve'member, assuring that contact of the upper Valve member 47 with the lower valve member 35 will close the ports 4t) through the latter, as shown in Fig. 2. Fluid under pressure is then imposed in a downward direction on the

valve members

47, 35, and, when the pressure of such uid exceeds the shear value of the screw 37 attaching the lower member to the valve stem 33, this screw will be disrupted to free the Valve stem from the lower member. It is apparent that any downward force on the valve stem 33 cannot move it and the ball member 19 in a downward direction, since the latter is in engagement with the supporting lugs or ribs 32. Following shearing of the screw 37, the uid will r force the lowe'r valve disc 35 in a downward direction within its housing 28 into a position in engagement with a stop shoulder 56 in the lower end of the lower valve housing portion.

The upper valve disc 47 cannot move downwardly very far after engaging the lower valve disc 35, since it will come to rest upon the stop shoulder 45 provided by the flange 39 of the intermediate housing portion. Accordingly, after the valve stem 33 has been freed from the lower disc 35, the upper and

lower discs

47, 35 again become longitudinally separated from one another, as illustrated in Fig. 3, which will then allow iiuid to pass in a downward direction through the ports 46 in the upper valve disc 47 into the lower housing portion 28 and through the ports 40 in the lower Valve disc 35, such iluid continuing outwardly through the lower end of the casing shoe. The ball valve member 19 and its .stern 33 can, however, now move in an upward direction until the ball engages its companion seat 17. Downward pumping of fluids through the casing string B can again shift the ball valve member in ak downward direction into engagement with its companion lugs 32, the huid continuing on downwardly through the upper disc ports 46 and the lower disc ports 40 for outward passage from the casing shoe A.

lt is to be noted that the hydraulic force imposed on the lower disc 35 to shear the valve stem screw 37 is also imposed on the ball 19 and on the ribs 32. It is desired to require a substantial pressure to free the ball i9; so as to guard against inadvertent disruption of the shear screw 37, as might occur under the influence of fluid surges that are due to sudden upward movements of the casing string, as well as stoppages of the casing string as it is being lowered in the well bore. Thus, a sudden lifting of the casing string B out of the rotary table slips (not shown) might cause the upper valve disc 47 to shift downwardly into engagement with the lower disc 35 before the casing string has been lowered to the desired depth.

To provide for a comparatively high unit iluid pressure to release the ball valve member 19, and to avoid the imposition of such high uid pressure on the ball valve member 19, itself, another frangible connection S7 is made between the rim portion 38 of the lower valve disc 35 and the lower housing portion 28. Such frangible connection may be in the form of one or more shear screws threaded through the lower valve disc and into the lower valve housing portion. These screws 57 may be made considerably stronger than the shear screw 37 holding the stem 33 to the lower valve disc 35. Accordingly, upon engagement of the upper disc 47 with the lower valve disc 35, the fluid pressure imposed upon the discs is required primarily to shear the screws 57 securing the valve disc 35 to the valve 28. Only a small portion of the downwardly directed hydraulic force is required to shear the valve stem screw 37. As a result, only a small part of the hydraulic force is imposed upon the valve stem 33 and the ball valve member 19. Similarly, the shear screws 57 bear the brunt of inadvertent downward movement of the upper valve disc 47 into engagement with the lower valve disc 35.

When the casing has been run to the desired depth in the well bore, fluid can be pumped down the casing string B, shifting the upper valve disc 47 into engagement with the lower valve disc 35, shearing both sets of

screws

57, 37, in order to enable the lower valve disc 35 to be shifted to its lowermost position disclosed in Fig. 3, longitudinally separated from the upper valve disc 47, and to also free the valve stem 33 and the ball 19 for upward movement to a position in which the ball engages its companion seat 17.

In the form of invention disclosed in Figs. 5 to 7, inclusive, the arrangement is substantially the same as in the embodiment illustrated in Figs. 1 to 4, inclusive. However, the hub 36a of the lower valve disc 35a is threaded, being screwed onto the lower threaded end 70l of they valve stern 33a. The valve stem has an intermediate reduced diameter portion 71 providing a weakened section at which the stem is to be pulled apart. As disclosed in Fig. 5, the rim or llange 38 of the lower valve disc engages the stop shoulder or flange 39 of the stop shoulder or flange 39 of the intermediate housing portion 22, in which position the ball valve member 19 rests upon its supporting ribs 32. The upper valve disc member 47 is illustrated as engaging the lower end of the upper valve housing 20. As in the other form of invention, fluid can flow upwardly through the lower ports 40, intermediate valve housing portion 22, upper ports 46, around the ball valve member 19 and into the upper casing sections B. When the ball is tobe released, fluid is pumped downwardly through the casing string B and around the valve ball 19, sliding the upper valve disc 47 downwardly into engagement with the lower valve disc 35a, as illustrated in broken lines in Fig. 5, which closes the lower ports 40 and allows liuid under pressure to be imposed upon the valve discs to a sufficient extent to overcome the tensile strength of the reduced diameter portion 71 of the valve stem 33a. When sufficient force is applied, the valve stem is pulled apart at its reduced diameter portion 71, thereby freeing the ball 19 and allowing it to move upwardly into engagement with its valve seat 17, such condition being illustrated in Fig. 6.

ln the form of invention just described, it is also desired to require a relatively high unit pressure to free the ball 19, but without imposing the force corresponding to such pressure on the ball 19 itself. Accordingly, the valve disc member 35a is caused to rest upon a shear ring or sleeve 72 which is secured to the lower housing portion 2S by one or more shear screws 73. When the upper valve disc 47 engages the lower valve disc 35a, the subjecting of the disc 35a to suflicient pressure will shear the screws 73 holding the sleeve 72 to the lower housing portion 2S, as well as pulling the stem 33a apart at its weakened section 71, the lower disc 35a and sleeve 72 being shifted downwardly until the latter engages the shoulder 56 at the lower end of the lower housing portion 23, the upper valve disc 47 coming to rest upon the shoulder 45 of the intermediate housing portion Z2 longitudinally spaced above the lower disc 35a (see Fig. 6). Accordingly, uids can be pumped downwardly through the casing string B and its casing shoe A, and any tendency for the iluids to pass in a reverse direction is precluded by upward movement of the ball valve member 19 into engagement with its valve seat 17, as illustrated in broken lines in Fig. 6.

In the form of invention illustrated in Figs. 8 to 11, inclusive, the parts are arranged in essentially the same manner as in the previously described forms of the invention. An upper valve disc 47a is disposed on a valve stern 33b that is circular in cross-section, this latter stem being threaded into a lower valve disc 35b which initially has its flange 38 engaging the lower end of the intermediate housing portion 22. The upper ports 46 are disaligned with respect to the lower disc ports 40, such disalignment being maintained by an alignment pin 75 secured to the lower disc 35b and extending upwardly into one of the ports 46 of the upper disc 47a adjacent the radially inward or small portion of such port. The upper disc 47a is also provided with circumferentially spaced, relatively small throttling ports 76 in alignment with the ports 40 in the lower valve disc 35b.

The apparatus A is run in the well bore on the lower end of the string of well casing B, the parts occupying the position illustrated in Fig. 8, in which the valve stem 33b and lower valve disc 35b keep the ball valve member 19 in engagement with its supporting lugs 32, and off its companion valve seat 17. The uid can tlow upwardly through the apparatus, passing through the ports 40' in the lower valve disc 35b, the large and

throttle ports

46, 76

in the upper valve disc 47a, and up around the ball valve member 19 into the upper casing sections B.

When it is desired to release the ball valve member 19, uid is pumpeddown through the casing string, carrying the upper valve disc 47a down along the circular valve stem 33h and into engagement with the lower disc 351;, the ports '76, 46, 40 being maintained in their respective positions of alignment and disalignment by the orienting pin 75. When the upper disc 47a engages the lower disc 35b, as shown in Fig. 9, the lower valve disc ports 4u are closed, eXcept for the relatively small passage through the throttle ports 76 in the upper disc. Such ports 76, however, do not prevent a back pressure from being built up on the upper disc 47a and the lower disc 35h, such pressure being exerted on the valve stem 33k,

and, when suicient, disrupting the latter at its weakened section 71 to free the valve ball 19 and allowing it to move upwardly into engagement with its companion valve seat 17, as shown in broken lines in Fig. 10. Following disruption of the valve stem` 3312, the lower disc 35b can be pumped downwardly away from the upper disc 47a and into engagement with the stop shoulder 56 in. the lower housing portion 28. Fluids pumped down through the casing string B can now pass around the ball valve member 19, continuing on down through the

ports

46, 76 in the upper disc 47a and through the open ports 411 in the lower disc 3517, for discharge from the casing shoe A.

. The throttle ports 7 6 prevent inadvertent building up of pressure to a great extent in the casing string B, since the fluid can pass in a restricted fashion through these ports '76 when the upper disc 47a engages the lower disc 3512. Thus, if sudden upward movement of the casing string B should cause the upper disc 47a to shift downwardly into engagement with the lower disc 35h, any relative down- I ward fluid movement in the casing string will result in the fluid bleeding through the throttle ports 76, without subjecting the lower disc 35b to a great pressure differential, which might inadvertently disrupt the valve stem 33!) at its weakened section 71.

The form of invention illustrated in Figs. 12 to l5, inclusive, is substantially the same as disclosed in Figs. to 7, inclusive, except that the valve stem 33e is twisted; so as to provide a steeply pitched thread or helical engagement with a companion bore 49a in the hub portion 48a of the upper valve disc 4712. As disclosed in Fig. 12, the upper disc 47h is in its uppermost position and the lower disc C engages the lower end 39 of the intermediate housing portion 22, precluding upward movement of the ball valve 19 into engagement with its companion seat 17. The ports 41) through the lower disc are in alignment with the ports 46 through the upper disc d7b; so that iluid passing upwardly through the apparatus does not have to change its direction of movement in passing through the discs, as must occur in the other forms of invention described above. As a result, there is less tendency for erosive wear to occur on the valve discs.

When the casing string B has been lowered to the desired depth, fluid can be pumped downwardly therethrough, shifting the upper valve disc 7b downwardly along the valve stem 33e. Due to the pitch of the valve stem and the companion pitch on the hub portion 48a of the upper disc, such 'downward movement causes the upper disc to be moved angularly of the stem and lower disc; so that when it comes into engagement with the lower valve disc 35C its imperforate or partitioned portions 53 are disposed across the lower disc ports 4G, whereas the imperforate or partitioned portions 41 of `the lower disc are disposed across the upper disc ports `16 (Fig. 13). The iluid in the well casing can now be subjected to'pressure suicient to urge the valve discs downwardly-and disrupt the valve stem 33C at its weakened portion 71, freeing 4the ball valve 19 for upward movement intoengagement with .its companion seat 17. Following such disruption, the .uid can actthrough'the upper disc ports 46 upon the lower disc 35a, shifting the latter downwardly away from the upper disc 47b and into engagement with the lower housing shoulder 56, the upper disc 47b only moving a slight distance into engagement with the shoulder 45 of the intermediate housing portion (Fig. 14). Fluids, such as cement slurry and the like, can now be pumped down the casing string B, flowing around the ball valve member 19, and continuing on down through the

open ports

46, 40 of the upper and lower discs for discharge from the casing shoe.

It is evident that the pitch of the helical valve stern 33C is such as to bring the upper disc ports 46 from the position of alignment disclosed in Fig. 12 to a position of disalignment, in which the ports of one disc are closed by the imperforate portion of the other disc, as disclosed in Fig. 13. As shown in the drawings, three ports are provided in each disc spaced degrees apart. Accordingly, the pitch of the stem 33C is such as to rotate the upper disc 47h substantially 60 degrees in moving downwardly into engagement with the lower disc. lt is, of course, evident that the pitch of the valve stem will be dilerent for different angular relationship of the ports 46, v40 with respect to each other, when the upper disc is in closed position upon the lower disc.

The inventors claim:

l. in apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict flow of uid through said tubular member; a lower ported member below said vaive member; means for preventing engagement of said valve member with said seat including releasable means engaging said lower ported member and said valve member; and an upper ported member above said lower ported member movable downwardly into engagement with said lower ported member to restrict fluid ow through said lower ported member whereby duid pressure can release said releasable means and allow engagement of said valve member with said seat.

2. ln apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict flow of uid through said tubular member; a lower ported member shiftably mounted in said tubular member below said valve member; means for preventing engagement of said valve member with said scat including releasable means engaging said lower ported member and said valve member; an upper ported member above said lower ported member movable downwardly into engagement' with said lower ported member to restrict fluid ow through said lower ported member whereby fluid pressure can release said releasable means and allow engagement of said valve member with said seat and downward movement of said lower ported member; and means for limiting downward movement of said upper ported member after release of said releasable means to enable said lower ported member to be shifted downwardly away from said upper ported member.

3. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve Seat on said member; a valve member engageable with said seat to restrict ow of iluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means engaging said lower ported member and said valve member; an upper ported member above said lower ported member movable downwardly into engagement with said lower ported member to restrict fluid ow through said lower ported member whereby fluid pressure can release said releasable means and allow engagement of said valve member with said seat; and means engaging said ported members to space them initially longitudinally from each other.

4. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict flow of fluid through said tubular member; a lower ported member shiftably mounted in said tubular member below said valve member; means for preventing engagement of said valve member with said seat including releasable means engaging said lower ported member and said valve member; an upper ported member above said lower ported member movable downwardly into engagement with said lower ported member to restrict tiuid flow through said lower ported member whereby iluid pressure can release said releasable means and allow engagement of said valve member with said seat and downward movement of said lower ported member; means engaging said ported members to space them initially longitudinally from each other; and means for limiting downward movement of said upper ported member after release of said releasable means to enable said lower ported member to be shifted downwardly away from said upper ported member.

5. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict flow of fluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means securing said lower ported member to said valve member, said releasable means comprising a valve stem secured to and depending from said valve member; and an upper ported member slidable downwardly along said valve stem into engagement with said lower ported member to restrict flow of uid through said lower ported member whereby fluid pressure can release said releasable means and allow engagement of said valve member with said seat.

6. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict flow of iluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including a valve stem secured to and depending from said valve member, frangible means securing said valve stem to said lower ported member; and an upper ported member slidable downwardly along said valve stem into engagement with said lower ported member to restrict iluid flow through said lower ported member whereby fluid pressure can disrupt said frangible means and allow engagement of said valve member with said seat.

7. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict flow of fluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including a valve stem secured to said valve member and lower ported member, said valve stem having a weakened portion; and an upper ported member slidable downwardly along said valve stem into engagement with said lower ported member to restrict fluid flow through said lower ported member whereby fluid pressure can disrupt said valve stern at said weakened portionv and allow engagement of said valve member with said seat.

8. In apparatus of the character described; a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said scatto restrict ow of uid through said tubular member; a lower ported member shiftably mounted in said tubular member below said valve member; means for preventing engagement of said valve member with said seat including releasable means securing said lower ported member to said valve member, said releasable means comprising a valve stem secured to an depending from said valve member; an upper ported member slidable downwardly along said valve stem into engagement with said lower ported member to restrict ow of fluid through said lower ported member whereby uid pressure can release said releasable means and allow engagement of said Valve member with said seat and downward movement of said lower ported member; means engaging said ported members to space them initially longitudinally from each other; and means for limiting downward movement of said upper ported member after release of said releasable means to enable said lower ported member to be shifted downwardly away from said upper ported member.

9. ln apparatus of the character described; a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict ilow of fluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means engaging said lower ported member and said valve member; an upper ported member above said lower ported member movable downwardly into engagement with said lower ported member to restrict fluid ilow through said lower ported member whereby uid pressure can release said releasable means and allow engagement of said valve member with said seat; and means for4 guiding said upper ported member into engagement with; said lower ported member to dispose the ports of said'. ported members out of alignment with each other to insure substantial closing of the port of one ported mem-y ber by said other ported member.

10. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a Valve member engageable with said seat to restrict flow of fluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means securing said lower ported member to said valve member, said releasable means comprising a valve stem secured to and depending from said valve member; an upper ported member slidable downwardly along said Valve stem into engagement with said lower ported member to restrict ow of uid through said lower ported member whereby uid pressure can release said releasable means and allow engagement of said valve member with said seat; and means for guiding said upper ported member along said valve stem into engagement with said lower ported member to dispose the ports of said ported members out of alignment with each other to insure substantial closing of the port of one ported member by said other ported member.

ll. In-apparatus of the character described: a tubular member adapted to form part of a conduit` string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict ow of Huid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means securing said lower ported member to said valve member, said releasable means comprising a valve stem secured to and depending from said valve member; an upper ported` member slidable downwardly along said valve stem into engagement with said lower ported member to restrict flow of fluid through said lower ported member whereby lluid pressure can release said releasable means and allow engagement of said valve member with said seat; and means providing a slidable spline connection between said valve stem and upper ported member to guide said upper ported member along said valve stem into engagement with said lower ported member to dispose the ports of said ported members out of alignams-1,022

ment with each other to insure substantial closing of the port of one ported member by said, other ported member.

l2. in apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict iiow of fluid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means securing said lower ported member to said valve member, said releasable means comprising a valve stem secured to and depending from said valve member; an upper ported member slidable downwardly along said valve stem into engagement with said lower ported member to restrict flow of iuidl through said lower ported member whereby iluidv pressure can release said reieasable means and allow engagement of said valve member with said seat; and means providing a helical spline connection between said valve stem and upper ported member to guide said` upper ported member along said valve stem longitudinally and rotationally into engagement with said lower ported member to dispose the ports of said ported members out of alignment with each other to insure substantial closing of the port of one ported member by said other ported member.

13. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict ow of uid through said tubular member; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means engaging said lower ported member and said valve member; an upper ported member above said lower ported member movable downwardly into engagement with said lower ported member to restrict fluid flow through saidl lower ported member whereby iiuid pressure can release said releasable means and allow engagement of said valve member with said seat; and means for effecting rotation of said upper ported member as it L- moves downwardly into engagement with said lower ported member to dispose the ports of said ported members out of alignment with each other to insure substantial closing of the port of one ported member by said other ported member.

14. ln apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve housing structure secured in said tubular member; a valve seat in said structure; a valve member engageable with said seat to restrict llow of fluid through said housing structure; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including frangible means engaging said lower ported member and said valve member to prevent engagement of said valve member with said seat, frangible means engaging said lower ported member and housing structure; and an upper ported member movable downwardly into engagement with said lower ported member to restrict fluid ow through said lower ported member whereby fluid pressure can disrupt both of said frangible means and allow engagement of said valve member with said seat.

l5. In apparatus of the character described; a tubular member adapted to iorm part of a conduit string positionable in a well bore; a valve housing structure secured in said tubular member; a valve seat in said structure; a valve member engageable with said seat to restrict flow of uid through said housing structure; a lower ported member below said valve member; means for preventing engagement of said valve member with said seat including releasable means securing said lower ported member to said valve member,V said releasable means comprising a valve stern secured to anddepending from said valve member,A frangible means engaging said lower portedmember andhousing structure; and an upper ported 12 member slid'able ,downwardly along said valve stem into engagement with said lower ported member to restrict fluid ow through said lower ported member whereby fluid pressure can release said releasable means and disrupt said frangible means to allow engagement of said valve member with said seat.

I6. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve housing structure secured in said' tubular member; a valve seat in said structure; a valve memberengageable with said seat to restrict flow ot fluid through saidY housing structure; a lower ported member below said valve member; means forl preventing engagement of said valve member with said seat including a valve stem secured to and depending from said valve member; frangible means securing said valve stem to said lower ported member, frangible means engaging said lower ported member and housing structure; and an upper ported member movable downwardly into engagement with said lower ported member to restrict Huid ilow through said lower ported member whereby liuid pressure can disrupt both of said irangible means and allow engagement of said valve member with said; seat.

17. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable i-n a well bore; a valve housing structure secured in said tubular member; a valve seat in said structure; a valve member engageable with said seat to restrict ow of duid through said housing. structure; means for preventing engagement of said valve member with said seat including a lower ported' member shiftably mounted in said tubular member below said' valve member, a valve stem secured to andy depending from said valve member, irangible means securing said valve stem to said lower ported member, frangible means engaging said lower ported member and housing structure; an upper ported member movable downwardly into engagement with said lower ported member to restrict iluid iow through said lower ported member whereby fluid pressure can disrupt both of said frangible means and allow engagement of said valve member with said seat and downward movement ofV said lower ported. member; means ony said housing structure engaging said ported members to space them initially longitudinally from each other; and means on said housing structure for limiting downward movement of said upper ported member after disruption of both of said frangibl'e means to enable said lower ported member to be shifted downwardly away from said upper ported member.

18. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in avwellV bore; a valve housing structure secured in said tubular member; a valve seat in said structure; a valve member engageable with said seat to restrict ow of uid through said housing structure; means for preventingV engagement of said valve member with said seat including a lower ported member shiftably mounted in said` tubular member below said valve member, a valve stem secured to and depending from said valve member, frangible meansj securing said valve stem to said lower ported' member, frangible means engaging said lower ported member and housing structure; an upper ported member movable downwardly into engagement with said lower ported member to restrict fluid ow through said lower ported member whereby fluid pressure can disrupt both of said frangible meansk and allow engagement of said valve member with said seat and downward movement'of'said' lower ported member; means on said housing structure engagingl said ported members to space them initially longitudinally from each other; means on said housingV structure for limiting downward movement of said upper ported member after disruption of both of said' frangible means to4 enable said lower ported member to be shifted downwardly away from said upper ported member; and means providing a slidable spline connection between said valve stem and upper ported member to guide said upper ported member along said valve stem into engagement with said lower ported member to dispose the ports of said ported members out of alignment with each other to insure substantial closing of the port of one ported member by said other ported member.

19. In apparatus of the character described: a tubular member adapted to form part of a conduit string positionable in a well bore; a valve seat on said member; a valve member engageable with said seat to restrict ow of uid through said tubular member; means for initially preventing engagement of said valve member with said seat comprising a valve stem engaging said valve member, said stem having a weakened section; and means en- 14 gageable with said preventing means for subjecting said stem to a tensile force to disrupt said stem at said weakened section to allow said valve member to engage said seat.

References Cited in the tile of this patent UNITED STATES PATENTS Re. 22,483 Burt May 23, 1944 2,178,845 Baker Nov. 7, 1939 2,373,005 Baker Apr. 3, 1945 2,471,383 Althouse et a1 May 24, 1949 2,647,584 Baker Aug. 4, 1953 FOREIGN PATENTS 209,821 Great Britain I an. 17, 1924

Claims

1. IN APPARATUS OF THE CHARACTER DESCRIBED: A TUBULAR MEMBER ADAPTED TO FORM PART OF A CONDUIT STRING POSITIONABLE IN A WELL BORE; A VALVE SEAT ON SAID MEMBER; A VALVE MEMBER ENGAGEABLE WITH SAID SEAT TO RESTRICT FLOW OF FLUID THROUGH SAID TUBULAR MEMBER; A LOWER PORTED MEMBER BELOW SAID VALVE MEMBER; MEANS FOR PREVENTING ENGAGEMENT OF SAID VALVE MEMBER WITH SAID SEAT INCLUDING RELEASABLE MEANS ENGAGING SAID LOWER PORTED MEMBER AND SAID VALVE MEMBER; AND AN UPPER PORTED MEMBER ABOVE SAID LOWER PORTED MEMBER MOVABLE DOWNWARDLY INTO ENGAGEMENT WITH SAID LOWER PORTED MEMEBER TO RESTRICT FLUID FLOW THROUGH SAID LOWER PORTED MEMBER WHEREBY FLUID PRESSURE CAN RELEASE SAID RELEASABLE MEANS AND ALLOW ENGAGEMENT OF SAID VALVE MEMBER WITH SAID SEAT.