US2854081A - Well cementing apparatus - Google Patents

Description

United States Patent WELL CEMENTIN G APPARATUS Bernard Kriegel, Los Angeles, Calif., assignor to Baker Oil. Tools, Inc., Los Angeles, Calif., a corporation of California Application July 11, 1955, Serial No. 520,988

14 Claims. (31. 166188) The present invention. relates to well bore'apparatus, and more particularly to apparatus useful in cementing a string of casing, and the like, in a well bore.

Under certain conditions, it is desirable to run a string of casing in a well bore to the required depth, condition the Well by pumping circulating fluid down through the casing for discharge from its lower portion, and subsequent upward passage around the casing to the top of the hole. Thereafter, the casing is to be cemented in place without contaminating the formation below the casing, or at least below a predetermined point in the casing. After the cement sets and hardens, the interior obstructions in the casing are drilled out through use of a suitable drilling bit.

It is an object of the present invention to provide improved apparatus to be incorporated in a casing string that embodies normally closed side ports, in which circulating fluid can be pumped completely through the apparatus, after which the well bore annulus around the apparatus and the interior of the apparatus below the side ports are positively sealed oif or closed and the ports opened, to cause cementitious material or other fluent substance to flow out through the side ports, such material or substances being prevented from moving down in the well bore below the sealed off region.

Another object of the invention is to provide apparatus of the character indicated, in which the sealing off of the annulus around the apparatus and the opening of the side ports is accomplished through use of a minimum number of parts or materials within the apparatus itself, thereby facilitating the subsequent drilling out of the interior of the apparatus.

A further object of the invention is to provide an apparatus of the character indicated, in which the sealing off and port opening functions are accomplished hydraulically by members movable along the external portions of the apparatus only, thereby keeping the interior of the apparatus relatively free of operating parts.

An additional object of the invention is to provide an apparatus of the character indicated, which is simpler in construction and more economical to produce.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of 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, with portions shown in side elevation, of an apparatus disposed within a well bore, with the parts in their initial positions;

Fig. 2 is a longitudinal section similar to Fig. 1, disclosing the apparatus packed-01f within the well bore and the side ports open;

Patented Sept. 30, 1958 ice , disclosing a portion of the annular piston and cylinder.

The apparatus specifically disclosed in the drawings constitutes a casing shoe forming the lower end of a string of well casing B to be lowered within a well bore C to the required extent, after which the casing is to be cemented in the well bore. If the apparatus A were incorporated in the casing string above its lower terminus, then it would be considered to he a casing collar.

As specifically shown, the apparatus includes a tubular casing member 10 made of several parts. Thus, its main central portion 11 is threadedly secured to an upper box 12 that is, in turn, threaded onto the lower pin end 13 of an adjacent casing section B thereabove. The lower portion of the intermediate tubular member 11 is threadedly secured within a lower abutment 14. For the purpose of facilitating lowering of the casing string in the well here, a cementitious plug 15 is cast within the lower portion of the tubular casing member, this plug being integrated to the tubular member, as by having cementi tious ribs 16 of material cast within longitudinally spaced internal grooves 17 in the tubular member 11. The plug 15 itself extends below the lower abutment 14, terminating in a rounded nose 18, to function as a guide capable of steering the casing past minor obstructions or restrictions in the well bore C as the casing string is being lowered therewithin. The plug has a central passage 19 therethrough to permit fluid to flow between the interior and the exterior of the tubular member 10. However, as described hereinbelow, fluid may be prevented from passing in a downward direction through the central plug passage 19, as by providing a valve seat 20 cast in the upper portion of the plug and surrounding the central plug passage, this seat being engageable by a suitable valve element 21, such as a trip ball, which can be dropped or pumped down the casing string B into engagement with the seat 20. To insure engagement between the valve element 21 and the seat 20, the upper end 22 of the lower plug 15 may be tapered or be made divergent in an upward direction, so that the ball will be guided toward the central plug passage 19 and seat 21.

It is desired to pump fluid down the casing string B and completely through the apparatus A for subsequent passage to the top of the hole through the annulus D around the casing string. Thereafter, the central passage 19 is to be closed against downward flow of fluid and the apparatus sealed off between its tubular member 10 and the wall of the well bore C, side ports 23 above the packed-01f region being opened. This will insure that all cementitious material pumped down the casing string B will pass out through the side ports 23 for upward travel through the annulus D surrounding the casing string, none of the cementitious material being capable of dropping down the well bore C, or through the central passage 19, to contaminate the formation below the apparatus A.

To accomplish the aforenoted purposes, an initially retracted packing structure 24 is disposed around the tubular member 11, the lower portion of this packing structure or sleeve, which may be made of rubber or rubber-like material, resting upon the lower abutment 14. The upper portion of the packing structure is engaged by the lower head or abutment 25 of an annular cylinder annular piston 27 disposed on its exterior above the ports 23, this piston being releasably secured to the tubular member by one or more shear pins or screws 28. The sleeve 29 of the cylinder 26 is integral with the lower head 25, extending upwardly along the annular piston 27, the uppermost end of the sleeve 29 being initially releasably secured to the upper box 12 of the tubular member 10 by one or more shear pins 30. When the shear pins 30 are intact, the upper end of the cylinder sleeve 29 may engage a downwardly facing shoulder 31 on the upper box.

Secured to the upper end of the sleeve 29 is a cylinder retaining device in the form of an upper head 32 attached to the sleeve 29 by a plurality of coupling pins 33. The upper head 32 contains a split ratchet ring or sleeve 34 having upwardly facing internal circurnfer ential ratchet teeth 35 adapted to coact with downwardly facing peripheral ratchet teeth 36 provided on the tubular member 11 below the upper box 12. The outer portion 37 of the ratchet ring 34 is in the form of a plurality of circumferential cam teeth adapted to coact with companion cam teeth 38 on the upper head 32, in order that any tendency of the upper head 32 and its cylinder 26 to move in an upward direction with respect to the tubular member 10 will cause the cam teeth 37, 38 to urge the ratchet sleeve 34 inwardly to maintain its teeth 35 engaged with the external teeth 36 on the tubular member 10. However, downward movement of the upper head 32 and the complete cylinder 26 along the tubular member 10 is permitted, inasmuch as the slope of the ratchet teeth 35, 36 will merely force the ratchet ring 34 outwardly, allowing it to ratchet freely over the teeth 36 on the tubular member. In effect, the upper head 32 is connected to the tubular member 10 by a one-way ratchet clutch, the cylinder 26 being movable downwardly along the tubular member, but its upward movement with respect thereto being prevented by the coaction of the ratchet teeth 35, 36 and the carnming action between the cam teeth 37, 38 to hold the split ratchet ring or sleeve 34 with its teeth 35 engaged with the tubular member ratchet teeth 36.

Fluid from within the tubular member 10 can pass outwardly through the ports 23 into an annular cylinder space 39 provided between the lower cylinder head 25 and the piston 27. Leakage of fluid in a downward direction between the lower head 25 and the tubular member 11 is prevented by providing a suitable side seal 40, such as a rubber or rubber-like O ring, in an internal groove 41 in the lower head which slidably and sealingly engages the periphery of the member 11. Leakage of fluid in an upward direction out of the cylinder space 39 around the annular piston 27 is prevented by an outer seal ring 42, such as a rubber or rubber-like ring, disposed in a peripheral groove 43 in the piston and slidably and sealingly engaging the inner wall 44 of the cylinder sleeve 29, Leakage of fluid along the inner surface of the piston 27 is prevented by a suitable inner seal ring 45, such as a rubber or rubber-like O ring, in an internal groove 46 in the piston, which slidably and sealingly engages the periphery of the tubular member 11.

Because of the relationship between the annular piston 27, cylinder 26 and tubular member 10, fluid cannot flow initially out of the cylinder space 39, the side ports 23 being initially closed. When in this closed position, the packing structure or sleeve 24 is in its retracted position, there being ample clearance between the exterior of the packing sleeve and the wall of the well bore C. The cylinder 26 is movable downwardly along the annular piston 27 and the tubular member to shift the lower piston head 25 toward the lower abutment 14, thereby foreshortening and compressing the packing structure, expanding it laterally outward into firm sealing engagement with the wall of the well bore C, as well as with the periphery of the tubular member 11 itself. The down ward movement of the cylinder 26 is permitted by the ratcheting action of the split ratchet ring 34 along the tubular member teeth 36. When the cylinder 26 is moved downwardly to a certain extent, an upper set of ports 47 in the cylinder sleeve 29, disposed below the upper head 32, is placed in communication with the tubular member ports 23, which effectively opens the ports 23 after the packing structure 24 has been sealed 011 against the formation, in the manner that will now be described in detail.

The apparatus A so far described can be run in the well bore C, with the passage 19 through the lower plug 15 fully open and with the parts around the exterior of the tubular member 10 occupying the position illustrated in Fig. l. The fluid in the well bore can flow upwardly into the casing B through the lower passage 19, unless some other apparatus in the well casing, which need not be used, precludes such upward flow. In any event, the casing string B is lowered in the well bore C to the desired location, whereupon the well can be conditioned by pumping circulating fluid down the casing string. All of the circulating fluid will pass outwardly of the shoe A through its central passage 19 for return flow around the apparatus and the annulus D around the casing string to the top of the well bore.

After the well bore C has been properly conditioned, the trip ball valve element 21 is dropped or is pumped down the casing string until it comes into engagement with its companion valve seat 20, which closes the central passage 19 against downward flow of fiuid therethrough. The pressure of the fluid in the well casing B and apparatus A can now be increased, this fluid under pressure passing through the ports 23, acting on the lower cylinder head 25 and piston 27. When the pressure of the fluid is sufiicient, it overcomes the strength of the. shear pins 30 (which are of much less shear strength than the pins 28), whereupon the cylinder 26 is shifted downwardly along the tubular member 10 and piston, to foreshorten the packing sleeve 24 and expand it outwardly until it firmly and securely seals against the wall of the well bore C. This action may normally occur with the side ports 47 in the setting sleeve 29 still disposed above the piston 27, so that the tubular member ports 23 are still in closed condition. However, an increase in the fluid pressure to the required extent will effect a shearing of the pins or screws 28 securing the piston 27 to the tubular member 11, the fluid then forcing the piston 27 upwardly along the tubular member and the cylinder sleeve 29 to a position above the sleeve ports 47, as disclosed in Fig. 2, which places the tubular member ports 23 in communication with the sleeve ports 47. Fluent material can now pass outwardly of the tubular member 10 through the side ports 23, moving through the annular cylinder space 39 between the tubular member 10 and cylinder 26, and exiting into the annulus D around the apparatus and the casing string B through the setting sleeve ports 47.

The required amount of cement slurry, or other cementitious material, can be pumped down the casing string B, this cement slurry being prevented from passing down through the lower plug passage 19 by the engagement of the valve element 21 with its seat 20. The cement slurry is forced to travel out through the side ports 23, the annular cylinder space 39, and the sleeve ports 47 into the annulus around the apparatus A, flowing upwardly through the annulus D around the casing string. None of the cement slurry can drop down along the casing to contaminate the formation therebelow because of the sealing action of the packing structure 24 against the wall of the formation, as well as against the periphery of the tubular member 11.

In the event that the well bore diameter is relatively large, then the side ports 23 will be opened in any event, despite the existence of pressures insufficient to shear the piston pins 23. The downward movement of the cylinder 26 along the tubular member 10 will carry the sleeve ports 47 below the piston 27, providing communication between the inner and outer sets of ports 23, 47. Thus, a practical limit is placed upon the extent of outward expansion of the packing sleeve 24 into engage" ment with the wall of the well bore. However, the packing sleeve can only be subjected to a certain maximum expanding pressure determined by the shear strength of the screws 28. As an example, the pressure may be 1000 p. s. i. When the predetermined pressure is exceeded, the piston shear screws 28 are disrupted, and the piston is moved upwardly to the position establishing communication between the tubular member ports 23 and the setting sleeve ports 47. Assurance is had that the packing struc-' ture will be held in its expanded condition by the coupling action of the ratchet sleeve teeth 35 with the peripheral teeth 36 on the tubular member 10.

After the cement has set and hardened, the interior of the apparatus can be drilled out, if desired. It is only necessary to remove the ball valve element 21, the valve seat (which may be made of a suitable material, such as rubber), and the cementitious lower plug 15. The packing structure 24 and setting and port controlling structure 26, 27, etc. cemented in place on the exterior of the apparatus, provide no obstruction to the interior of the v tubular member 10.

If desired, a back pressure valve construction may be embodied in the upper portion of the apparatus, to prevent return flow of the cement slurry into the casing string in the event the pressure within the casing string is bled off, and also to allow the apparatus to be floated in the well bore as it is being lowered to the desired location.

As disclosedin the drawings, an upper cementitious plug 60 may be cast in the tubular member 10, the peripheral ribs 61 on the plug being disposed within the longitudinally spaced internal grooves 62 in the tubular member. This plug 60 has a central passage 63 therethrough, and also carries a valve seat structure 64 disposed around this passage. Pivotally mounted on the valve seat structure, as by means of a suitable pivot pin 65, is a flapper valve head 66 which can swing upwardly into seating engagement with the valve seat 64, to prevent upward flow of fluid through the passage 63 and into the casing string B thereabove. However, when fluid is pumped downwardly through the apparatus, the flapper valve 66 is displaced to one side, such as disclosed in Fig. 2, to allow fluid to pass into the tubular member therebelow for downward flow through the central passage 19.

When it is desired to pack-off the structure 24 and open the side ports 23, the trip ball 21 is dropped or pumped down the casing string B, passing through the back pressure valve passage 63 and displacing the flapper valve head 66 to one side, the ball then engaging its companion seat 20. Thereafter, fluid under pressure can be imparted to the cylinder portion 26 of the apparatus to expand the packing sleeve 24 into sealing engagement with the wall of the formation, and to thereafter disrupt the piston shear pins 28 and shift the piston upwardly to the position in which the tubular member ports 47 are in communication with the setting sleeve ports 23. Cement slurry is now pumped down through the apparatus, passing through the upper passage 63, displacing the flapper valve 66 to one side, and then flowing out through the separate ports 23, 47 into the casing annulus D. Upon relieving of the pressure in the well casing B, any tendency for the cement slurry to flow back through the ports 47, 23 will be prevented by the upward movement of the flapper valve head 66 into sealing engagement with its companion seat 64.

The inventor claims:

1. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member adapted to be expanded outwardly; hydraulically operable means on the exterior of said tubular member engageable with said packing structure and disposed initially across said port in sealing engagement with said tubular member on opposite sides of said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said hydraulically operable means, said hydraulically operable means including instrumentalities movable along said tubular member by fluid under pressure within said tubular member to expand said packing structure and shift said instrumentalities to a position permitting such passage of fluid through said port.

2. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port;

' an initially retracted packing structure on the exterior of said tubular member below said port; hydraulically operable means on the exterior of said tubular member engageable with said packing structure and extending upwardly therefrom initially across said port in sealing engagement with said tubular member on opposite sides of said port to prevent passage of fluid through said port between the interior of the tubular member and the exterior on said hydraulically operable means, said hydraulically operable means including instrumentalities movable downwardly along said tubular member by fluid under pressure within said tubular member to expand said packing structure and shift said instrumentalities to a position permitting such passage of fluid through said port.

3. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port and an initially open longitudinal passage below said port; an initially retracted packing structure on the exterior of said tubular member; hydraulically operable means on the exterior of said tubular member engageable with said packing structure and disposed initially across said port in sealing engagement with said tubular member on opposite sides of said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said hydraulically operable means, said hydraulically operable means including instrumentalities movable along said tubular member by fluid under pressure within said tubular member to expand said packing structure and shift said instrumentalities to a position permitting such passage of fluid through said port; and means for closing said passage to enable fluid pressure to be built up in said tubular member for action upon said instrumentalities.

4. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port and an initially open longitudinal passage below said port; an initially retracted packing structure on the exterior of said tubular member below said port; hydraulically operable means on the exterior of said tubular member engageable with said packing structure and extending upwardly therefrom initially across said port in sealing engagement with said tubular member on opposite sides of said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said hydraulically operable means, said hydraulically operable means including instrumentalities movable downwardly along said tubular member by fluid under pressure within said tubular member to expand said packing structure and shift said instrumentalities to a position permitting such passage of fluid through said port;

and means for closing said passage to enable fluid pressure to be built up in said tubular member for action upon said instrumentalities.

5. In apparatus of the character described: a tubular member adapted to form part of a condm't string to be disposed in a well bore; said member having a side port;

an initially retracted packing structure on the exterior of said tubular member adapted to be expanded outwardly; hydraulically operable means on the exterior of said tubular member engageable with said packing structure and disposed initially across said port in sealing engagement with said tubular member on opposite sides of said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said hydraulically operable means, said hydraulically operable means including instrumentalities movable along said tubular member by fluid under pressure within said tubular member to expand said packing structure and shift said instrumentalities to a position permitting such passage of fluid through said port; and coengageable lock means on said instrumentalities and tubular member for holding said packing structure in expanded condition.

6. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port and an initially open longitudinal passage below said port; an initially retracted packing structure on the exterior of said tubular member below said port; hydraulically operable means on the exterior of said tubular member engageable with said packing structure and extending upwardly therefrom initially across said port in sealing engagement with said tubular member on opposite sides of said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said hydraulically operable means, said hydraulically operable means including instrumentalities movable downwardly along said tubular member by fluid under pressure within said tubular member to expand said packing structure and shift said instrumentalities to a position permitting such passage of fluid through said port; means for closing said passage to enable fluid pressure to be built up in said tubular member for action upon said instrumentalities; and coengageable lock means on said instrumentalities and tubular member for holding said packing structure in expanded condition.

7. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member adapted to be expanded outwardly; an annular piston on said tubular member; and an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and initially preventing passage of fluid through said port between the interior of said tubular member and the exterior of said cylinder; said cylinder being responsive to fluid under pressure in said tubular member to be shifted along said tubular member and piston to a position permitting such passage of fluid through said port and to expand said packing structure.

8. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member below said port; an annular piston on said tubular member above said port; and an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and extending upwardly therefrom across said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said cylinder; said cylinder being responsive to fluid under pressure in said tubular member to be shifted downwardly along said tubular member and piston to a position permitting such passage of fluid through said port and to expand said packing structure.

9. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member adapted to be expanded outwardly;

an annular piston on said tubular member; an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and initially preventing passage of fluid through said port between the interior of said tubular member and the exterior of said cylinder; said cylinder being responsive to fluid under pressure in said tubular member to be shifted along said tubular member and piston to a position permitting such passage of fluid through said port and to expand said packing structure; and coengageable lock means on said cylinder and tubular member for holding said packing structure in expanded condition.

10. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member adapted to be expanded outwardly; an annular piston releasably secured to said tubular member; and an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and initially preventing passage of fluid through said port between the interior of said tubular member and the exterior of said cylinder; said cylinder and piston being responsive to fluid under pressure in said tubular member, whereby said cylinder is shifted along said tubular member to expand said packing structure and said piston is shifted along said tubular member to a position permitting such passage of fluid through said port.

11. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member below said port; an annular piston on said tubular member above said port; means releasably securing said annular piston to said tubular member; and an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and extending upwardly therefrom across said port to prevent passage of fluid through said port between the interior of said tubular member and the exterior of said cylinder; said cylinder and piston being responsive to fluid under pressure in said tubular member, whereby said cylinder is shifted downwardly along said tubular member to expand said packing structure and said piston is released from said tubular member and is shifted upwardly along said tubular member to a position permitting such passage of fluid through said port.

12. in apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port; an initially retracted packing structure on the exterior of said tubular member adapted to be expanded outwardly; an annular piston releasably secured to said tubular member; an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and initially preventing passage of fluid through said port between the interior of said tubular member and the exterior of said cylinder; said cylinder and piston being responsive to fluid under pressure in said tubular member, whereby said cylinder is shifted along said tubular member to expand said packing structure and said piston is shifted along said tubular member to a position permitting such passage of fluid through said port; and coengageable lock means on said cylinder and tubular member for holding said packing structure in expanded condition.

13. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port and an initially open longitudinal passage below said port; an initially retracted packing structure on the exterior of said tubular member below said port; an annular piston on the exterior of said tubular member above said port; means releasably securing said piston to said tubular member; an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and extending upwardly therefrom across said port to close said port, said cylinder having an outlet disposed initially above said piston; and means for closing said passage to enable fluid pressure to be built up in said tubular member for action upon said cylinder and piston to shift said cylinder downwardly along said tubular member to expand said packing structure and to release said piston from said tubular member and shift said piston upwardly along said tubular member to a position above said cylinder opening to place said port and opening in communication with each other.

14. In apparatus of the character described: a tubular member adapted to form part of a conduit string to be disposed in a well bore; said member having a side port and an initially open longitudinal passage below said port; an initially retracted packing structure on the exterior of said tubular member below said port; an annular piston on the exterior of said tubular member above said port; means releasably securing said piston to said tubular member; an annular cylinder on the exterior of said tubular member and piston engageable with said packing structure and extending upwardly therefrom across said port to close said port, said cylinder having an outlet disposed initially above said piston; means for closing said passage to enable fluid pressure to be built up in said tubular member for action upon said cylinder and piston to shift said cylinder downwardly along said tubular member to expand said packing structure and to release said piston from said tubular member and shift said piston upwardly along said tubular member to a position above said cylinder opening to place said port and opening in communication with each other; and coengageable lock means on said cylinder and tubular member for holding said packing structure in expanded condition.

References Cited in the file of this patent UNITED STATES PATENTS 1,384,305 Crotto July 12, 1921 2,187,635 Stamps Jan. 16, 1940 2,232,325 Hamilton Feb. 18, 1941 2,488,819 Larkin Nov. 22, 1949 2,630,864 Lynes Mar. 10, 1953

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