US2813589A

US2813589A - Cementing shoe

Info

Publication number: US2813589A
Application number: US376301A
Authority: US
Inventors: Shelley G Woodruff
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1953-08-25
Filing date: 1953-08-25
Publication date: 1957-11-19
Anticipated expiration: 1974-11-19

Description

v. i9, 1957 s. G. WOODRUFF CEMENTING SHOE 5 Sheets-Sheet 2 Filed Aug. 25, 1953 INVENTOR.

SHEL/.Ey Gf MOD/@0pm rroQA/Eys.

CEMENTING SHOE 3 Sheets-Sheet 3' INVENTOR. Y SNEL/.LEX 6I Hfoonez/F;

TrQQA/Eys'.

S. G- WOODRUFF Nov. 19, 1957 Filed Aug. 25, 1953 H @y s United States Patent 2,813,589 CEMENTING SHOE Shelley G. Woodruff, Long Beach, Calif., assigixor to Baker Oil Tools, Inc., Los Angeles, Caiif., a corporation of California Application August 2S, 1953, Serial No. 376,361 19 Claims. (Cl. 166-225) The present invention relates generally to oil and gas wells, and more particularly to a novel well bore tool.

The well bore tool of the present invention finds particular use las a cementing plug. When setting casing in an oil or gas well bore it is common practice to pump a quantity of cement slurry down the casing, around a cementng plug Secured to land closing the lower end of the casing, and up into the annular space between the exterior of the lower end of the casing and the walls of the well bore adjacent thereto. Thereafter, the cementing plug may be removed so Ias to permit a second string of pipe to be lowered through the lower end of the casing string into the portion of the well bore therebelow.

It is a major object of the present invention to provide a novel cementing plug for use in a well bore.

Another object of the invention is to provide a cementing plug that includes a packer element which is lowered into the well bore in a retracted position and which may be expanded radially outwardly into sealing engagement with the walls of the well bore at a desired elevation.

A more particular object is to provide a cementing plug of the aforedescribed nature incorporating a closure element for the bottom of the plug formed of a readily drillable material, which closure element also acts as an expanding agent for the packer element.

Another particular object is to provide a cementing plug of the aforedescribed nature wherein its expanded packer element serves to dampen the shocks occurring during the drilling out of the closure element.

Another object of the present invention is to provide a cementing plug which is simple in design and rugged of construction whereby it is capable of foolproof operation.

A further object of the present invention is to provide a cementing plug of the aforedescribed nature which may be produced at a comparatively low cost.

It should be particularly noted that the well bore tool of the present invention may also be used as a formation tester. When so utilized it is capable of obtaining a `sample of the well bore liquid `at a desired elevation. The

details of construction of the well bore tool may be substantially the same whether it is utilized as a formation tester or as a cementing plug. Accordingly, the total number of tools required to be kept at a well site may be reduced. Hence, `another object of the invention is to provide a novel formation tester for use in a well bore.

These and other objects and advantages of the invention will be apparent from the following description, when taken in conjunction with the appended drawings, wherein:

Figure 1 is a central vertical sectional view of a well Vbore wherein is disposed a preferred form of cement plug y element has been expanded;

Figure 4 is a reduced central Vertical sectional view showing said cement plug being utilized during a cementling operation;

ICC

Figure 5 is a reduced central vertical sectional View showing the closure element of said cement plug being drilled through;

Figure 6 is a central vertical sectional View showing a formation tester that embodies the present invention, the packer element of said formation tester being disposed in a non-expanded position;

Figure 7 is a View similar to Figure 6, but showing said formation tester after its packer element has been expanded;

Figure 8 is a fragmentary central vertical sectional view showing an alternate form of well bore tool embodying the present invention; and,

Figure 9 is a view simil-ar to Figure 8, but showing the parts of said alternate form disposed in different positions.

Referring to the drawings, there is shown in rigures l through 5 a preferred form of cementing plug C embodying the present invention. This cement plug C broadly comprises a cylindrical housing member rl having its upper portion secured to the lower end of a string of weil casing 2 that is adapted to be lowered into a well bore W; a deformable packer sleeve mounted by the lower portion of the housing member ifi; and, a plug member P which is telescopically disposed wiihin the housing memoer l-l for downward axial movement relative thereto. rlhe inner periphery of the packer sleeve S is seen to be gradually reduced in circumrerenee along the lower portion of its length. `the plug member i includes a closure element, generally designated Z4, the lower portion of which is of downwardly tapered configuration. Upon the imposition of iiuid pressure against tne upper surface of the closure element 24, the plug member P will be forced downwardly within the housing member l-l from its original position of rigure 2 to its lower position of Figure 3. During such downward movement, the tapered sides of the lower portion or' the closure element 24 will wedge the packer sleeve :s radially outwardly into sealing engagement with the walls of the well bore W.

l Referring to Figure i, the cement plug C iinds particular use in conjunction with the operation. of setting tapered casing strings within an oil well bore W, although its value is not to be considered limited solely to such use. ln setting such a casing string, a first length of casing 26 is lowered into the well bore to a desired depth. Thereafter, cement slurry 28 is forced downwardly through the casing into the annular space between the exterior of the casing string 26 and the walls of the well bore W. Control over the flow of this cement slurry into the well bore may be effected by means of one of the cement plugs C of the present invention in a manner to be fully set forth hereinafter. After the cement slurry 23 has hardened sumciently, the closure element (not shown) of the cement plug C' is removed in a manner also to be disclosed hereinafter. Next, a string of casing 22 smaller in diameter than the first casing string is lowered into the well bore until its lower end is spaced at the desired elevation within the well bore. Cement slurry is then forced downwardly through the casing, the cement plug C being employed to control the flow of cement between its exterior surface and the walls of the well bore W.

Referring now to Figure 2 for a more detailed descripton of the cement plug C, it will be seenfthat the upper end of the cylindrical housing member Hl is formed with internal threads 3i) that are shown engaged with external threads 32 formed on the lower end of the casing string 22. The lower end of `housing member H is formed with external threads 34, which threads are engaged with internal threads 36 formed on a ring element 38. The ring element 38 is bonded to the upper portion of the packer sleeve S. The housing member H rs formed with a plurality of ports 40 at its intermediate portion. Below these ports 40 the inner wall of the housing member is formed with an annular groove 42.

The plug member P includes an expansion tube member 44 that encompasses the closure element 24. The closure element 24 will preferably be formed of a readily drillable material such as wood, and includes an upper portion 46 of somewhat smaller outer diameter than the inner diameter of tube member 44. The lower portion of closure element 24 ares radially outwardly to approximately the maximum inner diameter of the packer sleeve S'. as indicated at 48. From this point the closure element tapers downwardly at approximately the same angle as that of the inner periphery of the packer sleeve S, as indicated at 50. The lower end of the expansion tube member 44 is rigidly connected, as by welding, to a lock ring 52. The upper portion of the expansion tube 44 is formed with an external annular groove 54 wherein is disposed a radially expandible snap ring 56, which snap ring is constantly biased outwardly against ,the inner walls of the housing member H. The upper portion 46 of the closure element is rigidly secured to the lower .portion of expansion tube 44 by one or more pegs or pins 58. These pins 58 should also be formed of a readily drillable material such as Wood. and they are disposed within radially extending bores 60 formed .in the closure element and apertures 62 formed in the lower portion of the expansion tube member 44.

v.The cement plug C is run into the hole with its parts disposed in their position of Figure 2. At this time the snap ring 56 will exert sufficient pressure against the inner wall of the housing member H to restrain the tube member 44 from downward axial movement relative thereto. Referring now to Figure 3, at such time as the cement nlug C has reached the elevation within the well bore W at which its packer sleeve S is to be expanded. a Huid such as conventional drilling fluid or mud will be pumped downwardly from the earths surface through the interior of the casing string 22. This uid vrwill exert downward force upon the upper surface of the closure element 24 nf sufficient magnitude to overcome the resistance offered by the snap ring 56. Accordingly,

then-nlug member P will be forced downwardly within the housing. During such downward movement the tapered sides of the closure element 24 will wedge the packer sleeve S radially outwardly into sealing engagement with the walls of the well bore W, the upper end of the lock sleeve 52 finally reaching a point adjacent the lower end of the packer sleeve S. At this time the `snap ring 56 will have been moved to a point adiacent the groove 42 formed in the cylindrical housing H. Inasmuch as this snap ring is constantly biased radially outwardly, it will then snap into the groove 42 so as to lock the expansion tube member 44 against further downward movement within the housing H. The ports 40 will meanwhile have been uncovered by the sides of the expansion tube member 44 so as to place the portion of the well bore W above the expanded packer sleeve S in communication with the interior of the housing mem- 'Der H and hence with the inside of the casing string 22.

If desired. the downward packer sleeve-expanding force applied against the upper surface of the closure element 24 may be supplied by the cement slurry 28 pumped through the well casing 22. Such cement may be forced through this casing by means of drilling duid, a top cementing plug, generally designated 60, being interposed between the upper end of the cement slurry and the bottom of the column of drilling liquid. As clearly indicated in Figure 4, the cement slurry 28 will be caused to flow radially'outwardly through the housing member ports 40 and into the annular space between the exterior lsurface of the housing H and the casing 22 and the walls of the well bore W. When the underside of the top cementing plug 60 reaches the upper end of the expansion tube member 44, its continued downward progress will be halted by the abutment of its lower end with the upper end of the closure element 24. A rubber-like cup 62 mounted by the upper end of the top plug 60 will serve to seal the drilling liquid from .passing through ports 40.

Referring now to Figure 5, after the cement 28 has hardened sufliciently, it is necessary to remove the plug member P from the lower end of the cementing plug C. Such removal may be accomplished by means of a drill bit 64, which drill bit will have a smaller outside diameter than that of the casing string 22 and the expansion tube member 44. During the rotation of this drill bit 64, the resiliency of the packer sleeve S will tend to absorb the drilling shocks that would normally be applied to the cement plug P and transferred to the cement 28. ln this manner the bond between the cement 28 and the exterior surfaces of the housing member H and the casing string 22 will not be adversely affected. It should be noted that the lock sleeve 52 of the expansion tube member 44 aids in retaining the packer sleeve S wedged in place during this drilling operation. It should likewise be noted that the expanded packer sleeve serves to prevent any of the cement thereabove from falling downwardly into the well bore W. When a sufficient portion of the closure element 24 has been drilled away, this element will fall free of the tube member 44. The cement plug C will then be similar in appearance to the cement plug C shown in Figure l.

Referring now to Figures 6 and 7, the formation tester F embodying the present invention is substantially similar in construction to the aforedescribed cementing plug C. Thus. it includes a cylindrical housing member H having its upper portion secured to the lower end of a pipe string 22; a deformable packer sleeve S mounted by the lower portion of the housing member H; and, a plug member P which is, telescopically disposed within the housing member H for downward axial movement relative thereto. The inner periphery of the packer sleeve S is gradually reduced in circumference along the lower portion of its length. The lower portion of the plug member P is downwardly tapered. The intermediate portion of the housing member H is formed with a plurality of ports 40 that are normally covered by the sides of the expansion tube member 44 of the plug member P. The plug member P includes the expansion tube member 44 and a closure element, generally designated 24a, which is rigidly attached thereto by a plurality of pegs or pins 58. Both the closure element 24h and the pins 58 may be formed of a readily drillable material such as wood. The upper portion of the tube member 44 mounts a radially expandible snap ring 56 in an annular groove 54.

In operation, the formation tester F is run into a well bore W with its parts disposed in their positions shown in Figure 6. At this time the snap ring 56 will restrain downward axial movement of the plug member P relative to the housing. Referring now to Figure 7, at such time as the formation tester F is disposed at the elevation at which a test is to be conducted, a fluid will be pumped downwardly from the earths surface through the interior of the pipe 22. The downward pressure exerted upon the upper surface of the closure element 24b will force the plug member P downwardly within the housing member H. During such downward movement the tapered sides of the lower portion of the closure element will wedge the packer sleeve S radially outwardly into sealing engagement with the sides of the well bore. The downward movement of the plug member will continue until the snap ring 56 snaps outwardly into the groove 42 of the housing member. At this time the ports 40 of the latter will be uncovered so as to `admit well bore uids into the interior of the housing member and hence that of the pipe string 22, as indicated by the arrows'in Figure 7.

Referring now to Figures 8 and 9, there is shown an alternate form of well bore tool embodying the present invention, which tool may be utilized either as a cementing plug or as a formation tester.4 This well lbore tool includes a housing member H and a packer sleeve S which are substantially similar to those shown in the preceding figures. The plug member P thereof, however, is of unitary construction, being formed of a single block of a readily drillable material such as wood.l The upper portion of the plug member P includes an annular groove 54 wherein is disposed a radially expandible snap ring 56. The lower portion of the plug member defines a downwardly tapered packer sleeve expanding element 24h. In Figure 8 the well bore tool is shown before its packer sleeve S has been expanded, while in Figure 9 the latter has been expanded and the ports 40 of the housing member H uncovered. It will be apparent that drilling out the plug member P will permit the packer sleeve S to return to its original retracted position whereby the tool may readily be returned to the earths surface.

` While there has been shown and described three forms of well bore tools embodying the present invention, it will be apparent that yet other forms are possible. For example, it is possible to force'an acidizing uid or the like, outwardly through the ports 40 rather than cement slurry. It should also be noted that although a radially expandible snap ring 56 has been shown for locking the plug member against unlimited downward axial movement with the housing member, other suitable lock means may be utilized. These and other similar modifications and changes fall within the spirit of the invention and the scope of the following claims.

I claim: l. A well bore tool for use with a pipe string, comprising: a cylindrical housing attachable to said pipe string; a deformable packer sleeve secured to said housing, the inner periphery of said packer sleeve being gradually reduced in circumference along at least a part of its length to provide such part with an inside diameter substantially less than the inside diameter of said housing; and, a plug member telescopically disposed within said housing for axial movement relative thereto, said plug member having an element which is tapered whereby it may engage said part and wedge said packer sleeve radially outwardly into sealing engagement with the wall of said well bore upon relative axial movement between said housing and said plug member to seal off the annulus between said housing and the wall of said well bore.

2. A well bore tool for use with a pipe string, cornprising: a cylindrical housing member attachable to said pipe string; a deformable packer sleeve havingits upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof and having an inside diameter substantially less than the inside diameter of said housing member; and, a plug member telescopically disposed within said housing member for axial movement relative thereto, said plug member including a downwardly tapered lower portion adapted to engage said frusto-conical configuration and wedge said packer sleeve radially outwardly into sealing engagement with the wall of said well bore upon relative axial movement between said members to seal off the annulus between said housing member and the wall of said well bore.

3. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof and having an inside diameter substantially less than the inside diameter of said housing member; and, a coaxial plug member telescopically disposed within said housing member for axial movement relative thereto, said plug member being formed of a readily d rillabl'erjmaterial and having a downwardly tapered lower portionafor closing-.off the lower end of said housing memberand adapted t engage said truste-'conical coniguration and wedge, said packer sleeve radially outwardly into sealing engagement with the wall of said well bore upon downward movement of said plug member relative to said housing member to seal oit the annulus between said housing member and the wall of said well bore.

4. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable tothe lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower lportion of said housing, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof; a coaxial plug member telescopically disposed within said housing member for axial movement relative thereto, said plug member being formed of a readily drillable material and having a downwardly tapered lower portion for `closing olf the lower end of said housing member and adapted to wedge said packer sleeve radially outwardly into `seal,- ing engagement with the walls of said well bore upon downward movement of said plug member relative t-o said housing member; and, a port formed in said housing member that is originally covered by said plug member but which is uncovered when said plug member moves downwardly a predetermined distance relative to said housing member so as to connect said well bore with the interior of said housing member.

5. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a deformable packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof; a plug member of readily drillable material telescopically disposed within said housing for axial movement relative thereto, said plug member including a downwardly tapered lower portion; a radially movable lock element carried by one of said members that is constantly biasedtoward the other of said members; and, a radially extending abutment surface formed on the other of said members, said plug member being adapted to wedge said packer sleeve radially outwardly into sealing engagement with the walls of said well bore upon its downward movement within said housing member, and said lock element engaging said abutment surface when said plug member has moved downwardly a predetermined distance.

6. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a deformable packer sleeve having its upper end secured to the lower portion of said housing member, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof; a plug member telescopically disposed within said housing member for axial movement relative thereto; means for locking said members against further relative axial movement when said plug member has been moved downwardly a predetermined distance; a port formed in the lower portion of said housing member that is adapted to connect said well bore with the interior of said housing member when said plug member has been moved downwardly said predetermined distance; and, a closure element formed on said plug member having a downwardly tapered lower portion that is adapted to wedge said packer sleeve radially outwardly into sealing `engagement with the walls of said well bore as` said plug member is moved downwardly.

7. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing', the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof; an expansion tube member telescopically disposed within said housing member for axial movement relative thereto; means for locking said members against further relative axial movement when said expansion tube member has been moved downwardly a predetermined distance; a port formed in the lower portion of said housing member that is originally closed by said expansion tube member but which is uncovered when said tube member moves downwardly said predetermined distance; and, a closure element having a downwardly tapered lower portion that is yadapted to wedge said packer sleeve radially outwardly into sealing engagement with the walls of said well bore upon downward movement of said expansion tube member said predetermined distance.

8. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a deformable packer sleeve having its upper portion secured to the lower portion of said housing member, the inner periphery of said sleeve being of truste-conical configuration with the smallest circumference disposed at the lower portion thereof; an expansion tube member telescopically disposed within said housing member for axial movement relative thereto; a radially movable snap ring carried by one of said members, said snap ring being constantly biased toward the other of said members; an annular groove formed on the other of said members adapted to receive said snap ring when said tube member has been moved a predetermined distance downwardly within said housing member; a port formed in the lower portion of said housing member that is originally closed by said expansion tube member but which is uncovered when said tube member moves downwardly said predetermined distance; and, a closure element having a downwardly tapered lower portieri that is adapted to wedge said packer sleeve radially outwardly into sealing engagement with the walls of said well bore upon downward movement of said expansion tube member said predetermined distance.

9. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the vlower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of truste-conical configuration with the smallest circumference disposed at the lower portion thereof; an expansion tube member telescopically disposed within said housing member for axial movement relative thereto; an annular groove formed in the outer wall of said tube member; a radially expandible snap ring disposed in said groove; a second annular groove formed in the inner wall of said housing member for receiving said snap ring when said tube member has been moved downwardly therein a predetermined distance; a lock ring formed at the lower end of said tube member below the bottom of said housing member, said` lock ring being of larger .outer diameter than said tube member; a closure element coaxially disposed within said tube housing member, the portion of said closure element adjacent the bottom of said housing being ared radially outwardly to approximately the outer diameter of said lock ring, said closure element then tapering downwardly at substantially the angle of the inner periphery of said packer sleeve; and, a radially extending pin rigidly connecting said closure element to said tube member, said closure element and said pin being formed of wood.

l0. A well bore tool for use with a pipe string, cornprising: a cylindrical housing member attachable to the lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being ofnfrusto-conical configuration with the smallest circum- Xference `disposed at the lowerportion thereof; an expansion tube member teleseopically disposed within said housing member for axial movement relative thereto; means for locking said members against further relative axial movement when said plug member has been moved downwardly a predetermined distance; a port formed in the lower portion of said housing member that is originally closed by said expansion tube member but which is uncovered when said tube member moves downwardly said predetermined distance; a lock ring formed at the lower end of said tube member below the bottom of said housing member, said lock ring being of larger outer diameter than said tube member; a closure element coaxially disposed within said housing member, the portion of said element adjacent the bottom of said housing being ilared radially outwardly to approximately the outer diameter of said lock ring, said closure element then tapering downwardly at substantially the angle of the inner periphery of said packer sleeve; and, a radially extending pin rigidly connecting said closure element to said tube member, said closure element and said pin being formed of wood.

11. A cementing plug for use with a pipe string that is adapted to be lowered into a well bore, comprising: a cylindrical housing member attachable to the lower end of said pipe'string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of frusto-conical coniiguration with the smallest circumference disposed at the lower portion thereof; a coaxial plug member formed of a readily drillable material and having an upper portion that is telescopically disposed within said housing member and a downwardly tapered lower portion adapted to wedge said packer sleeve radially outwardly into sealing engagement with the walls of said well bore upon downward movement of said plug a predetermined distance; means for locking said members against further relative axial movement when said plug member has been moved downwardly a predetermined distance; a port formed in said housing member that is originally covered by said plug member but which is uncovered when said plug member moves downwardly a predetermined distance relative to said housing member so as to connect said well bore with the interior of said housing member, the top of the upper portion of said plug member being disposed adjacent the lower edge of said port after it has moved said predetermined distance.

12. A cementing plug for use with a pipe string that is adapted to be lowered into a well bore, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of truste-conical configuration with the smallest circumference disposed at the lower portion thereof; a coaxial plug member formed of a readily drillable material and having an ripper portion that is telescopically disposed within said housing member and a downwardly tapered lower portion adapted to wedge said packer sleeve radially outwardly into sealing engagement with the walls of said well bore upon downward movement of said plug a predetermined distance; a radially movable lock element carried by one of said members that is constantly biased toward the other of said members; a radially extending abutment surface formed on the other of said members for receiving said lock element when said plug member has moved downwardly a predetermined distance; and, a port formed in said housing member that is originally covered by said plug member but which is uncovered when said plug member moves downwardly a predetermined distance relative to said housing member so as to connect said well bore with the interior of said housing member, the top of the upper portion of said plug member being displaced adjacent the lower edge of said port after it has moved said predetermined distance.

n13. JA-ee'mentingplugfor use with valpip'e string that is adapted to be lowered into a well bore, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof; a coaxial plug member formed of a readily drillable material and having an upper portion that is telescopically disposed within said housing member and a downwardly tapered lower portion adapted to wedge said packer sleeve radially outwardly into sealing engagement with the walls of said well bore upon downward movement of said plug a predetermined distance; an annular groove formed in the outer wall of said plug member; a radially expandible snap ring disposed in said groove; a second annular groove formed in the inner wall of said housing member for receiving said snap ring when said plug member has been moved downwardly therein a predetermined distance; and, a port formed in said housing member that is originally covered by said plug member but which is uncovered when said plug member moves downwardly a predetermined distance relative to said housing member so as to connect said well bore with the interior of said housing member, the top of the upper portion of said plug member being displaced adjacent the lower edge of said port after it has moved said predetermined distance.

14. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a deformable packer sleeve having its upper portion secured to the lower portion of said housing member, the inner periphery of said sleeve being of frusto-conical coniguration with the smallest circumference disposed at the lower portion thereof; an expansion tube member telescopically disposed within said housing member for axial movement relative thereto; a radially movable snap ring carried by one of said members, said snap ring being constantly biased toward the other of said members; an annular groove formed on the other of said members adapted to receive said snap ring when said tube member has been moved a predetermined distance downwardly within said housing member; a port formed in the lower portion of said housing member that is originally closed by said expansion tube member but which is uncovered when said tube member moves downwardly said predetermined distance; and, a closure element formed of a readily drillable material telescopically disposed within said tube member and formed with a downwardly tapered lower portion that is normally positioned within the frusto-conically configured portion of said sleeve whereby it may wedge said sleeve outwardly into sealing engagement with the walls of said well bore upon downward movement of said tube member said predetermined distance, the top of said closure element being disposed adjacent the lower edge of said port after said tube member has moved said predetermined distance.

l5. A well bore tool for use with a pipe string, comprising: a cylindrical housing member attachable to the lower end of said pipe string; a rubber-like packer sleeve having its upper portion secured to the lower portion of said housing, the inner periphery of said sleeve being of frusto-conical configuration with the smallest circumference disposed at the lower portion thereof; an expansion tube member telescopically disposed within said housing member for axial movement relative thereto; means for locking said members against further relative axial movement when said plug member has been moved downwardly a predetermined distance; a port formed in the lower portion of said housing member that is originally closed by said expansion tube member but which is uncovered when said tube member moves downwardly said predetermined distance; a lock ring formed at the lower end of said tube member below the bottom of said housing member, said lock ring being of larger outer diameter than said tube member; and, a closure element formed of a readily drillable material telescopically disposed within said tube member and formed with a downwardly tapered lower portion that is normally positioned within the frusto-conically configured portion of said sleeve whereby it may wedge said sleeve outwardly into sealing engagement with the walls of said well bore upon downward movement of said tube member said predetermined distance, the top of said closure element being disposed adjacent the lower edge of said port after said tube member has moved said predetermined distance, the top of said lock ring being disposed adjacent the lower edge of the expanded sleeve after said tube member has moved said predetermined distance.

16. A well tool for use with a pipe string, comprising: a cylindrical housing attachable to said pipe string; a deformable packer sleeve secured to said housing, a portion of said sleeve having an inside diameter substantially less than the inside diameter of said. housing; and an expander member telescopically disposed within said housing for axial movement relative thereto and engageable with said portion to force said packer sleeve radially outward into sealing engagement with the wall of a well bore upon relative axial movement between said housing and member to seal off the annulus between said housing and the wall of said well bore.

17. A well tool for use with a pipe string, comprising: a cylindrical housing attachable to said pipe string; a deformable packer sleeve secured to said housing, a portion of said sleeve having an inside diameter substantially less than the inside diameter of said housing; and an expander member telescopically disposed within said housing and movable by fluid under pressure within the pipe string and said housing axially within said housing and said portion to engage said portion and force said packer sleeve radially outwardly into sealing engagement with the wall of a well bore to seal oli the annulus between said housing and the wall of said well bore.

18. A well bore tool for use with a pipe string, comprising: a cylindrical housing attachable to said pipe string; a deformable packer sleeve secured to said housing, a portion of said sleeve being disposed below the lower end of said housing and extending laterally toward the axis of said housing; and an expander member telescopically disposed within said housing for downward movement therewith and engageable with said portion to force said packer sleeve radially outward into engagement with the wall of a well bore to seal off the annulus between said housing and the wall of said well bore.

19. A well tool for use with a pipe string, comprising: a cylindrical housing attachable to said pipe string; a deformable packer sleeve secured to said housing, a portion yof said sleeve having an inside diameter substantially less than the inside diameter of said housing; and an expander member telescopically disposed within said housing for axial movement relative thereto and engageable with said portion to force said packer sleeve radially `outward into sealing engagement with the wall of a well bore upon relative axial movement between said housing and member to seal off the annulus between said housing and the wall of said well bore; said housing having a port originally closed by said expander member, but which is opened when said expander member moves axially within said housing to expand said packer sleeve radially outward.

References Cited in the le of this patent UNITED STATES PATENTS 1,711,125 Owen Apr. 30, 1929 1,734,884 Simpson Nov. 5, 1929 1,915,771 Wickersham et al June 27, 1933 2,027,783 Martin Ian. 14, 1936 2,161,309 ODonnell June 6, 1939 2,162,261 Layne June 13, 1939