US1432017A

US1432017A - Oil-well-casing cementing shoe

Info

Publication number: US1432017A
Application number: US451032A
Authority: US
Inventors: Erd V Crowell
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-06-15
Filing date: 1921-03-09
Publication date: 1922-10-17
Anticipated expiration: 1939-10-17

Description

E.V. CROWELL.

OIL WELL CASING CEMENTING SHOE.

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APPLICATION FILED MAR. 9| 192|.

E. V. CROWELL. OIL WELL CASING CE'MENTING SHOE.

APPLICATION FILED MAR. 9, 1921.

Patented Oct. 17, w22.

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` i WIM/8858 E. V. CROWELL. OIL WELk CASING CEMENTING SHOE.

. APPLICATION FILED MAR. 9. 192|. 1,432961?, Patented Oct. 17, E922,

, 3 SHEETS-SHEET 3. 5 l! Y ze?? g A A www Patented Oct. 17, 1922.

l I S ERD V. CROWELL, OF TULSA, OKLAHOMA.

OIL-WELL-CASING CEMENTING SHOE.

Original application led June 15, 1920,.Seria1 No. 389,151. Divided and this application led March 9, 1921. VSerial No. 451,032.

To all whom t may Concern Be it known that I, ERD V. CiiowELL, a citizen of the United States, and a resident of Tulsa, in the county of Tulsa and State of Oklahoma, have invented certain new and useful Improvements in Oil-Well-Oasing Oeinenting Shoes, of which the lfollowing is a specification.

`My invention relates to improvements in well casings, particularly those of the type employed in oil and gas wells,l and it consists in the constructions, combinations and arrangements herein described and claimed.

One of the foremost objects of the invention is to provide a cementing shoe for use in connection with an oil or gas well cas- .ing, by means of which a cementiiig mixture, as for example mud-fluid, can be ejected from the lowerinost section or oil string to fill the space between the foil string and well bore and thus seal the formation seat against the seepage of water.

A further object of the invention is to provide a cementing shoe for oil or gas well casings, which offers the distinctiveand exclusive advantage of providing means for placing a cementing mixture behind the oil string while the well is expelling oil and gas and the casing is resting on its formation seat.

A further object of the invention is to provide means for introducing a cementing mixture into the. space between. the oil string and wall of the hole, without having to first plug the hole beneath the casing, raise the casing or work against the high pressure of the oil and gas.

A further object of the invention is to provide -means in oil or gas well constructions, enabling the making of a water-tight seal between the casing and rock formation independently of the casing shoe on the lowermost extremity of the oil string or the texture of thel landing formation on which the shoe rests.

A further and important object of the invention is to provide means, including a valve mechanism forming part of the well casing, enabling placing a mud-fluid or other ceiiienting mixture behind the oil string while it is resting on its formation seat, and oil and gas are being expelled through the casing.

Other objects of my invention will appear in the following specification, reference bein had to the accompanying drawings, in w .ich

Figure l is a longitudinal section illustrating the casing cementing shoe and its associated parts in the operative position in the oil string of a well casing, said casing being shown resting on its formation seat near the bottom of the bore.

Figure 2 is a detail sectional View illustrating the mudding packer in the approximate position to have the upper and lower packer rubbers expanded against the cementing shoe,

Figure 3 is a similar View, taken at right angles to the section in Figure 2, illustrating the mudding packer in the operative f position opposite. the mud valves in the cementing shoe, f

Figure 4 is a detail side elevation of the mudding packer before the rubbers are expanded, the supporting slips at the bottom being shown disassembled for purposes of illustration,

FigureI 5 is a detail longitudinal section of' the cementing shoe with lits mud valves,

Figure 6 is a detail horizontal section on the line 6 6 of Figure o, showing how the.

mud valves ai'e mounted,

Figure 7 is a detail plan View of the rubber-expanding spider, and

Figure 8 is a detail horizontal section taken substantially on the line 8-8 of Figure 4, and showing the springs and associated parts of the supporting slipsz This is a division of my co-pending application for Letters Patent for oil well casing cementng shoes, filed June l5, 1920, Serial No. 389,151.

In order that the reader might be able to more fully appreciate the purpose of the invention, it is thought well to preface the description of the construction and mode of operation by a brief description and gas well casing operation. Casing, as now used in oil field operation, in either iron of the oil :icoI

or steel tubular pipe, the kinds and sizes A complete column of pipe or casing as placed in the bore of oil wells, is commonly referred to as the string of casing. rlhe fundamental purpose of the oil well casing is that of protection, that is to say, to keep the water and other foreign substances from falling into the shot hole at the bottom and thereby either crowding the oil back from the bore or obstructing the lower end of the bore in such a manner that neither oil nor gas can flow.

The problem of water exclusion from oil wells is merely that of inserting a string of water-tight casing, so that its bottom is tightly lodged below the lowest water-bearing stratum and above thetop of theproductive oil sand, thereby s'ealing the water off from descent below the casing, thus preventing water originating above from invading the productive oil or gas sands below.

ln drilling oil or gas wells, the formations passed through as the depth increases consist of alternating`layers of lime-stone, shale, and occasionally a stratum of sand. The Shale layers predominate over the lime layers as regards number and thickness, and again the lime layers `predominate over the sand layers in the same manner. Usually the lunderground water finds its channels of flow in the lime or sand strata, the water flowing through the sand stratum generally above or below a lime stratum.`

As the depth of the hole is increased during the drilling operation, water producing lime or sand strata are encountered, the

water thus released by the puncturing of the strata by the drill point, settling in the hole and filling it with Water. The drilling operations are thus greatly retarded, due to the cushioning effect the water has on the drilling operation of the tools.

Again, the water released from the lime strata washes down over the shale strata below, causing the -shale to cave, slough out .and fall down the hole. A loose shale formation may thus cave to such an extent as to even entirely bury the tools. An enormous amount of additional work is required in thereafter excavating the material and recovering the tools.

Referring to Figure 1, it is obvious that for the casing to successfully perform its function of protecting the shot hole, in the productive oil or gas sand, as represented at O, from being flooded with water that originates in the strata above the casing seat S, it is necessary that the casing shoe 2 make a positive water-tight seal or bond with the rock formation at S.

lhen the casing has been landed on its format1on`seat S and the casing shoe 2 has made a positive water-tight seal with the i formation seat S, it is said to .have made a shut-off, as commonly referred to. The present day methods of effecting a positive water-tight seal between the casing shoe 2 and the formation seat S, separate themselves into two main classifications', the formation shut-off and the cement shut-off.

Formation shut-off is the term commonly applied to the operation of excluding water, where the casing, with a shoe of some kind, is landed or driven into a stratum of shale or clay, using no artificial bond. Cement shut-ofi1 is the term commonly applied to the operation of excluding water, where cement or mud-Huid is used to form a bond between the casing and the formation in which the shoe of the casing is landed.

Formation conditions, and texture of the landing formation are often such that the .casing shoe 2 is prevented from making a seal or bond with the formation seat S. Consequently, water finds its way down around the casing shoe 2, and the casing l thus fails in its primary function of protecting the productive oil or gas sand from being flooded with water from above, commonly referred to as top water.

It is generally conceded by those experienced in the art, that `the only means of providing a water-tight bond or seal between the casing and the formation, independent of mechanical packers, is by the application of cement or mud-fluid behind thecasing and above the casing shoe 2. It is the prime purpose of the device to provide means of placing cement or mud-fluid behind the casing of oil or gas Wells in a way more ex- `pedious than is commonly practiced, and

at the lowermost extremity resting on an annular projection of rock or other material, commonly known as the formation seat S. The bore of the well merges with the opening O in the stratum of oil or gas sand, commonly known as the shot hole.

The very first consideration is to produce a water-tight joint or bond between the casing shoe 2 and the formation seat S. In order that the need of the invention may be more fully appreciated, and a particular and exclusive advantage more thoroughly understood, it is thought well to explain the method, now practised, of placing a sealing materia-l behind the .casing of oil or gas wells.

Therefore, digressin brie-fly from the description of the invention, it is Well to bear in mind that'the method, no w practised, is

to insert or Abuild a temporary plug in the the introduction of the sealing material through the casing. l

After the temporary plug is thus in place, and the oil and gas effectually sealed in, the sealing mater-ial is then introduced through the casing where it falls on top of the plug,

' when it is necessaryv to lift the casing from its .format-ion seat so as to let the sealing material out into the annular space between the casing and wall of the bore.v After the sealing material has been forcedvfrom the casing, with a column of water above, to fill the annular space outside the casing, the' casing is again let down, and the temporary plug in the hole drilled out.

` Now, due to a heavy internal sand pressure and consequent violent expulsion of oil and gas, under heavy pressure, it is often impossible to insert or build a temporary plug beneath the formation seat S, and above the oil or gas sand, as such a procedure requires, Aside from the impossibility of ap-` plying a sealing material by this method, in' many instances, it offers the disadvantage of having to suspend production for a time.

lt is also regarded `by those experienced inI the art, that. the question of determining just when the casing is lifted from its formation seat, and just when the cementing material has been forced out of the casing to fill the annular space outside of the casing, offers one of the most perplexing problems in the application of this method, the accurate determination of which is necessary for assurance of its successful operation.

By referring to Figure 1, a particular and exclusive advantage of my invention may be observed, whereby means are provided for the introduction of a sealing material through the tubing 25, while oil and gas is being expelled through the casing 1, exterior of the tubing 25, thus obviating the necessity of having to temporarily plug the well in, or raise and lower the casing.

Reverting now to the description of the invention: There are two major parts of which vitv is constituted, namely, the cementing shoe 3, and the mud packer 4. The cementing shoe 3 is very much like one of the sections of the well casing, it being in fact, joined. to one of them by the coupling 5 in Figure 1. Both ends are threaded; one for the coupling 5 and the other for the bowl 6, which in turn is very much like an ordinary coupling since it has the same eX- ternal and internal diameters.

Two or more valves 7 normally close ports 8 in the annular enlargement 9 of the shoe 3, each being held in place by rather powerful arcuate leaf springs 10, which are secured to the shoe at 11. The springs occupy an annular groove 12 and are sheltered therein by the overhanging parts of the enlargement 9. l

Either the flange 13 or a series of projections in the same place, which would accomplish the same purpose, support the mud packer'4 in the bowl 6 of the cementing shoe, by virtue of the engagement of the slips 14 therewith. These slips are segmental as shown in Figures 4 and 8, having keeper slots 15 shaped to suit the keys 16 on the slip cage 17. Recesses 18 in the slips 14 accom' modate springs .19 which force the slips outwardly into contact with the adjacent wall.

The c-asing bowl 6 is machined from a steel forging and when thus machined is provided with a tapering portion 20 which aids in contracting the slips 14 when pulling the mud packer 4 out of the casing. The

surfaces of the slips 14 are slightly convexed to facilitate the withdrawal of the mud packer. The adjusting ring 21 on the lower end of the shell of the packer 4, abuts the slidable packing mechanism on the shell to lift said mechanism out of the casing upon withdrawingthe packer.

The upper threaded end of the packer I shell carries the collar 22, into which the spider 23 is screwed, the legs 24 of the spider resting on the collar. The mud tubing 25 is screwed into the spider from above, while the delivery tube 26 is screwed into the spider from beneath. But by virtue of the fact that the delivery tube is integrally joined to the packer shell 4 at the right angled outlet extension 27, it would be more nearly correct to say that the spider 23 is screwed onto the delivery tube 26.

There are two packer rubbers on the shell 4; the upper rubber 28 is located below the collar 22, the other rubber 29 below the mudluid distributor ring 30. This ring has an annular concavity 31 which readily permits the mud-Huid to flow toall outlet valves 7 from the point of discharge 27. The distributor ring 30 is slidable on the shell 4 and has a slot 32 which enables relative movement of the ring in respect to the outlet 27 without obstructing the outlet.`

A base ring 33 provides the foundation for the lower packer rubber 29, in that the lower packer rubber employs the base ring as an abutment against which to expand, and in that the base ring holds the lowermost rubber out of the casing bowl 6. llt is necessary that the lowermost rubber 29 expands against the shoe 3 slightly below the discharge valve 7, the parts of the mechanism being so proportioned that this acthe rubbers 28 and 29 are gradually compressed and expanded against the wall of the shoe 3, while the discharge outlet 27 ultimately finds 'a position in line with the valve 7.

It is important that particular attention be called to valves 7, upon which depend the practical value and possible operation of the invention; it is to be understood, therefore, that modifications and changes as to their 'particular design and number may be made without departing from the spirit of the invention. l

The operation may now be easily followed. As the well drilling operation progresses and various water-beauang strata are encountered, sections of piping are let down. These become progressively smaller as the depth of the well increases, and the uppermost ones are known as water stringsf As mentioned above, the lowermost section of piping is known as the oil string, and a portion thereof is shown in Figure 1. The lcasing shoe 2 is solely for the purpose of imparting strength to the-oil string and keep it from crimping due to the enormous weight .imposed thereon. It is very seldom that a satisfactory joint forms of its own accord between the shoe 2 and the formation seat S. A mud seal meets all requirements satisfactorily.

The cementing shoe 3 is introduced in the. casing l at the desired location from the bottom, the mud-fluid outlet valves 7 being normally held closed by the leaf springs 10. The tubing 25 with lits mud packer mechanism 4 is lowered into the casing, the slips 14 rubbing against the casing walls by virtue of the springs 19 behind them, until they encounter the supporting ledge 13 near the bottom of lthe casing bowl 6.

1t is the weight of the tubing 25 on the spider 23 and associated parts, whereby the upper and

lower rubbers

28 and 29 are caused to expand from the positions in Figures 2 and 5 to that shown in Figures 1 and 3. They form a perfect seal between the shell 4 of the packer and the shell 3 of the shoe, the concavity 31 of the mud distributor ring 30 constituting an annular channel which leads the mud fluid to the two or more discharge valves 7.

,1t is of utmost importance to observe that while mud-fluid lis being pumped through the tubing 25, gas and oil are. enabled to es- Cape up through the casing but around the tubing. The pressure of the mud fluid opens the valves 7 so that the material flows out into the space between the casing and the wall of the bore B, filling all crevices and excluding the water which flows from water bearing strata, from the casing of the well. Naturally, none of this water can seep into the shot hole O because of the secure seal around the shoe 2. If desired, mud fluid may be pumped Iin until it overflows at the top, and when the seal is completed, the mud packer 4is withdrawn by pulling on the tubing 25.

`While the construction and arrangement of the improved casing ceIhe'nting mechanism as herein described and claimed, is that of a generally preferred form, obviously modifications and changes may be made without departing from the splirit of the invention or the scope of the claims.

I claim l. A well casing resting on its formation seat in a well bore open to a productive stratum, and means forming one of the sections of the casing, including valve mechanism enabling the ejection of sealling material from inside of the casing into the space between the casing and bore, while fluid flows through the casing from said productive stratum. 2. The combination of a well casing, and means located in the casing for conducting sealing material to a point of discharge in the wall of the casing, in a direction opposite to that of the fluid flow in the casing without obstructing it.

3. The combination of a well casing, and

its formation seat in a bore opened to a productive stratum, a conduit 4on the interior of the casing conducting sealing material in the direction opposite to the flow of fluid from the stratum without obstructing said flow, and a valve apparatus embodied as a section of the casing, through which the sealing materiial from the conduit is ejected into the space between the casing and bore. to Aform a tight joint around the formation seat.

4. The combination of a well casing and its formation seat in a bore opened to a productive stratum-a conduit on the interior of the casing conducting sealing material lin the direction opposite to the llow of fluid from the stratum without obstructing said flow, a valve apparatus embodied as a Section of the casing, through which the sealmg material from the conduit is ejected into the space between the casing and bore, and f cementing shoe embodied as one of the .cas- .j

ing sections, with a plurality of valved' ports a delivery tube interiorly of the casling for conducting sealing material to said ports; and means operatively assocla-ted with a part of said tube for securing a tight joint against the casing above and below said ports.

6. The combination of a well casing, a cementing shoe embodied as .one of the casing sections, with a plurality of valved ports; a delivery 'tube Iinteriorly of the casing lfor conducting sealing material to said ports; means operatively associated with a part of said tube for securing a tight joint against the casing above and below said ports, and means for circumferentially distributJing the sealing material to said portsv from the discharge of said tube.4

7. The combination of a Well casing, a cementing shoe embodie'd as one of the cas-` ing sections, with valved. ports; tubing interiorly of t-he casing conducting sealing material to said ports, includling a packen shell spaced from the casing but enabling the passage of iiuid through the casing while the sealing material flows in said tubing; and packing means in the space between said shell and casing forming a tight joint-above and below salid valved ports.

8. The combination of Aa well casing, a cementing shoe embodied as one of the casing sections, with valved ports; tubing interiorly of the `casing conducting sealing material to said ports, including a packer shell spaced from the casing but enabling the passage of fluid through the casing whilethe sealing material flows in said tubing; packing means in the space between said shell and casing forming a tight joint above and below the valved ports, and a ring surrounding the packer shell and formingan abutment for said packer means, for distributing the sealing material to said ports.

9. The combination of a well casing, with a cementing shoe having a plurality of valved ports; tubing interiorly of the casing for conducting seallng material to the ports, including a packer shell spaced from the casing and slightly movable relative thereto; a ring surrounding said shell for distributing the sealing material to all ports, including a slot preserving communication of the tubing outlet during said shell movement; a ring bridging the slot at the upper end of the distributor` ring, packer means in the space between the shell and casing, abutting the bridge and distributor rings; and means carried by the shell and tubing for expanding the packer means to form a tight joint above and below said valved ports.

10. r1`he combination of a well casing, a cementing shoe coupled in the casing, with a plurality of valved ports; tubing interiorly 'of the casing conducting sealing material to said ports, including a packer shell capable of slight movement in respect to the casing; packer means on the shell to form a tight joint above and below said ports, and means carried by the shell engageable by a portion of the casing at a predetermined place to constitute an abutment against which said packer means expand.

ll. The combination of a well casing, including a cementing Shoe withy a plurality of valved ports, and a casing bowl with a supporting ledge; tubing inside the casing conducting sealing material to said ports. and including a packer shell capable of slight movement in respect to the casing; normally contracted pac-ker means carried by the shell, for making a tight joint between the shell and casing above and below said ports, and means carried by the shell engageable 'with said supporting ledge to constitute an abutment against which said packer means eX- pand during said slight movement of the shell.

1.2. The combination of a packer shell, with a slip cage; a casing bowl in respect to which the packer shell has slight movement, including a. supporting ledge; and slips carried by the cage, with sprlngs for pressing the slips against the wall of the casing bowl thereby to engage the ledge and provide an abutment.

13. The combination of a packer shell, with a slip cage having recesses and keys, a casing bowl in respect to which thel packer shell has slight movement, including a supporting ledge; and slips occupying the recesses, with openings receiving the keys for limiting the outward movement of the slips, including springs urging the slips into contact with the bowl wall as the packer shell moves downwardly, said slips finally engaging the ledge to form an abutment.

14. The combination of a cementing shoe, with a series of valved ports, and an attached casing-bowl of an internal diameter larger than that of the shoe, including a supporting ledge; and a packer shell spaced from the shoe, with upper and lower packer rubbers in said space, and abutment means engageable with the ledge, against which said rubbers expand to form tight joints.

15. The combination of a well casing, including a cementing shoe with a series of valved ports; and tubing for conducting sealing material to the ports, with an integral packer shell spaced from the casing f and carrying upper and lower packer rubbers, and a spider and collar respectively carried by the tubing and shell, for expanding the rubbers at the sides of the ports by virtue of the weight of the tubing.

16. The combination of a well casing with a Xed abutment and a series of valved ports; tubing in the casing for conducting sealing material to the ports, made integrally with a packer shell spacedly located from the casing; an abutment carried by and movable with the shell into engagement with said fixed abutment` packer rubbers respectively above and below said series of ports in the space between the shell and casing, and means including a spider, mutually car-` ried by the tubing and shell for imposing the weight of the tubing on the rubbers to expand them into tight engagementwith the casing, the lowermost rubber abutting the movable abutment through a. base ring.

17. The method of sealing wells, consisting of lowering a well casing into permanent engagement with the formation seat near the bottom of a bore. and introducing sealing material into the bore around the casing Without stopping the flow of Huid through the casing.

18. The method of sealing wells, consisting of lowering a valved well casing into permanent location on the formation seat of a bore, and introducing sealing material into the casing to flow out of the Valve and ll the surrounding bore.

ERD V. CROWELL.