US2636563A - Oil well finishing tool - Google Patents

Description

April 28, 1953 D. o. RoLLlNs 2,636,563

on. WELL FINIsx-IING Toor.

Filed March 12, 1948 3 Sheets-Sheet l April 28, 1953 D. oi RQLUNS 2,636,563

oIL WELL FINISHING Toor.

Filed March 12, 1948 3 Sheets-Sheet 2 fw 2. f4 (#43 46 7J if 6J Z6 'ze if if Z 676 /f do 4'/ 4 2 J@ JNVENTOR.

Patented Apr. 28 1953 OIL WELL FINISHING TOOL Derrial O. Rollins, Hackberry, La., assigner of three-eighths to Carroll V. Radke and oneeighth to Getty Manufacturing & Tool Company, Jennings, La., a firm Application March 12, 1948, Serial No. 14,422

v 'This invention relates to improvements in oil well finishing tools and more particularly to a j' rchoke and valve assembly adapted to be attached ito -the bottom' end of' a tubing string extended downwardly through a well to flow oil, sulphur,

1 brine or other fluid mineral substance to the top inf the well.

In the modern practice of drilling deep wells,

'rsuch as oil and sulphur wells, the well bore or ihole is maintained full of a uid mud of very Thigh specific gravity which replaces the material removed from the well bore and holds any soft formation against collapsing into the well bore and also maintains suflicient pressure on any gas, oil or other fluid mineral encountered to prevent such mineral from' being forced to the surface, blowing out the well. Such deep wells are drilled i by a rotary bit attached to the bottom end of a string of tubing sections collectively referred to as the drill stem and frequent tests are made by means of this string of hollow tubing to determine the nature of the formation encountered at different depths. Thus the depth below the surface of strata cf oil bearing sands or other mineral deposits is accurately known. As the well is drilled a casing or liner is continuously positioned in the bore and this casing is lowered and the drilling operation carried on through the column of fluid mud in the well bore.

After the well has been drilled to the level of the major oil bearing sands or deposit of other fluid mineral the next step is to now the well, l-that is allow the oil or other mineral to rise to 1 thesurface. In the past it has been necessary to swab the well, that is, remove the column of 'fluid' mud from the well to permit the fluid mineral to rise, The present method of flowing does not necessarily require removal of al1 of the mud and involves lowering a string of open, flow tubing, usually with a restricted opening or choke in the bottom end, through the mud column to the level of the oil bearing sands or other mineral deposit and then pumping or swabing the flow tubing to remove the mud therefrom and bring the petroleum or other mineral to the surface. This removal of the mud from the flow tubing is a laborious and time consuming operation and introduces a serious danger of the well blowing out as a portion of the mud column is removed.

It is among the objects of the present invention to provide an improved method of ilowing wells which involves maintaining the bottom end of the string of.- iiow tubing closed as the string is lowered through the mud column in the well bore, thus maintaining Vthe flow tubing empty and I free of mud until it has been lowered to operative y position at the producing level, and then opening the bottom end of the string to permit the im- Vmediate flow of mineral from the producing level, and to provide suitable apparatus for carrying out such method including a combined choke and valve assembly so arranged that the valve will remain closed while the tubing string is being lowered to operative position, and can be opened at any depth by a. valve opener lowered from the surface, in which the valve and chokeassembly is effective to prevent leakage of mud or other fluid into the tubing string before the valve is opened, can be arranged to provide for washing or acidifying the well by uid forced into the flow tubing at the surface level, is bodily retrievable from the bottom of the flow tubing string when desired, provides for the use of chokes of different volumetric capacity and is simple, durable and economical in construction and easy to apply and operate.

Other objectsand advantages will become apparent from a consideration of the following description and appended claims in conjunction with the accompanying drawings wherein:

Figure 1 is a diagrammatic elevation showing a choke and valve assembly, illustrative of the invention, in operative position on the bottom end of a string of iiow tubing in a well bore;

Figure 2 is a longitudinal cross section of the choke and valve assembly;

FigurevS is a longitudinal elevation of a fragmentary upper portion of the assembly showing a releasable assembly lock in a different operative position from that shown in Figure 2;

Figure 4 is a longitudinal cross section through the valve unit per se, showing the valve closed;

Figure 5 is a view similar to Figure 4 showing the valve open;

Figure 6 is a top plan View of the valve unit;

Figure 7 is a longitudinal elevation of valve opener;

Figure 8 is a view illustrating the manner in which the valve opener opens the valves; and

Figure 9 is a view similar to Figure 8 showing a modified valve opener for opening a modified form of valve.

With continued reference to the drawings, there is illustrated in Figure 1 a well bore i0 having vstringof flow tubingis fragmentally illustrated;

as indicated at I2, and to the bottom end of the bottom section l2 of the flow tubing string there Yscrews or rivets 5215.

is attached a choke and Valve assembly illustrative of the invention and generally indicated at i3. The assembly I3 is conveniently attached to the bottom end oi the tubing section I2 by a coupling sleeve ld threaded onto external screw threads provided on the tubing section and the valve and choke .unit adjacent `,their adjoining ends.

The choke and valve assembly is illustrated in detail in Figures 2 and 3 and comprises ...aan elongated cylindrical casing l5 having external screw threads l5 and I? at the lowerfandupper ends thereof, spaced apartinternal cylindrical recesses le and I9 providing v'between them an annular internal shoulder ...20, andlthreelateral ports 2l intermediate the length thereof. The cylindrical internal recess I9 opens to theupper end of the casing and the portslarefclosedby respective valve plugs 22 mounted on litherends of respective leaf springs 23 positioned in longi- ,tudinal` grooves prevded .in .the outersurfacepf .the ,Ga-Sins and Seeuretlat theirgqnnosite :ends

,t the .casineby ,Suitablefastenerssuch,as .the ,annular de'ector ,25 surrounds .the lported v.portion of 'the vcasing ,circumspacially thereof ands secured at Vits ,upper end to the casing :by suitable means such ,as welding, as indicated` at 2.6.

An elongated tubular` mandrel 1211s positioned inthe casing t andisprovided on theoutersur- .tace thereof with two .spaced ,apart ,packing as- .Semblies the upper of whichfis indicated at 22S and the flower at 29. vThe end l.portions of the mandrel are reduced "to provide ,spaced ,apart annular shoulders 3.o and 3i I ,providingfabutments A155cv: ltheflower end of 'the-upper packing and .the

upper end o'f'thelowerpacking respectively. Each packing comprises a ring 32 .bearing against the corresponding shoulder, packing rings 33 ,of suitable flexible material, such vas .leather .or rubber, separated by an annular Separator '34 an endring 35 corresponding to the ring ,3l and opposed thereto, and a packing nut 3.6 threaded Onto .the ,corresponding screw threaded `end portion of the mandrel. The p ackings ,2,8 andl 4may be adiustably expanded by tightening the ,packing nuts 36 and provide a duid tightseal between tthe mandrel 2l .and the internal .bore of .the casing 1,5. .An elongated, perforated ,nipple 3.1 is secured to rthe lower ends `Vof the mandrel .by -a .cylindrical poupling 3S threaded onto .the .externally .screw- .lhreaded upper end .of .the ,nipple `and onto the externallyscrew ,threaded lower endof .the inandrel .upon which the .packing nut .36 is `also threaded. The lower fend of the mandrel `=is also internally screw threaded and receives ya choke tube or bean l0 which has an externally l.screw .threaded portion threaded into the :mandrel vand a restricted bore lll therethrough for limiting the flow of iuid .mi-neral, such .as petroleum, through the choke and valve assembly. The :bottom end of the choke tube is bored or made otherwise non- `circular to provide a wrench head 42 for threading the tube into .and out of the mandrel. The .choke tube is thus rendered interchangeable and a tube having a bore of any desired volumetric capacity within the operative limits of .the apparatus can be used.

A tubular, locking ,slip mandrel, generally indicated at A3, is provided in its lower end with internal screw threads ,and is threaded onto the externally screw threaded upper end of the packing mandrel 21. This looking vslip mandrel has, intermediate .its length, an upwardly tapering .Goncal portion 44, a cylindrical portion 45 at the rlo ...mandrel Lchokeandvalve from the bottom of the string of .iiow `tubing in .the Awell. `Vvcarrier ftlispprovided with another annular en- .largemclfltintheinner side of which are pro- At its lower end the vided angularly spaced openings which receive the upper ends of locking slips 59. The locking slips fdd lare --pivotally secured in the carrier by Aknobs 5.9 on the upper ends of the locking slips seated in the openings in the carrier and the lower ends of the. locking slipsare -enlarged .and

somewhat spade .shaped and Vprovided .at'ltheir .upper ends with inclinedshnul'clersl which Igenvgage under the internal shoulder 2li of .casing l-l 5 'to c releasably' lock themandrelsin .operative position .in the casing. vA wire 52 extending around the 'locking slips and seated in notches provided in angularly .spaced radial extensions 53.011 "the -locking slip vmandrel holds Ithe "locking .slipsin operative position on the slip mandrel'.

In the varrangem'en't illustrated, .there .are three locking slipshaving "their center'lines spaced at substantially vequal angular intervals around the slip mandrel. 'When ltneassenbled 'mandrel-s are in' the/'position inthe casing, illustrated .in 'Figure v`2, the l'oring slips are 'forced :outwardly bythe conicalp'ortion "lill :of the slip mandrel .to engage under 'the shoulder 2B, but, when themandrels are positioned vfurther Vtoward the 'bottomend of the casing and thecarrier 4l israised on the slip mandrel the lower ends of the slips are moved inwardly, as illustrated in vFigure `3, out of engagement with the shoulder 2B so 'that the mandrels can be withdrawn from the casing` In the form of the invention illustrated in Eigures 2 and 3 a valve unit, generally indicated at 'ljis secured in the upper ends of .the Vlocking slip mandrel i3 by an Vinternally flanged nut 5.5 screw threaded onto the upper ends of the vslip mandrels. This vnutmay be locked in .positionon the slip mandrel by .a set screw extendmg through fthe wall of the vnut.

The .valve unit 5H, as illustrated in .detail in Figures 4 `and .5., `comprises `a cylindrical valve 'boch/15.5 khaving a bore of circular cross section therethrough, a bevelled valve seat 5'! in its low-- er .end and an outwardly extending annular ange d8 around its upper end whichiiange is yengaged .by lthe internal flange of nut 55 to secure lthe valve unit 5d in the slip mandrel, and a valve plunger 59 slidable in the bore of the housing. The plunger 59 has on its lower end a gate or piston El! having a bevelled upper surface Si adapted to engage the valve seat vEl and a conical lower end 62 for reducing the lfrictional-resistance of iiuid ow past the valve gate. At its upper end the plunger 5l is provided with a `knob 63 and intermediate its length is a transverse aperture 64 adapted to receive a shear pin S5 which serves to maintain the valve `in closed position, as illustrated in Figure s. The lower end cf the valve body bore is provided with a counterbore 6G and annularly spaced uid passages 61 lead from the upper end of this counterbore to the .upper .end surface of the valve body. The

counter bore provides at its upper end an annular shoulder 68 internally of the valve body and the stem 5S is provided below the transverse aperture 64 with a second transverse aperture $9 the ends of which open into downwardly extending diametrically opposed slots 'lil in the valve stem. A U-shaped spring 'Il having outwardly turned lower end portions is mounted in the stem 59 so that its bight portion is seated in the transverse apertures 69 and its legs are disposed in the longitudinal slots 10. When the valve stem is moved to valve opening position, as illustrated in Figure 5, the outwardly turned lower end porti'cns of spring il engage under internal annular shoulder B8 to retain the valve in open position.

In using the improved choke and valve assembly, the assembly is attached to the bottom kend of the rst section of the flow tubing string at the upper end of the well by the coupling I4. The tubing section is then lowered into the well and additional sections consecutively added thereto until the choke and valve assembly is brought to the production level in the well, the valve unit .54 remaining closed while the ow tubing string is being lowered through the mud column in the well to exclude mud from the interior of the flow tubing. When the choke and valve assembly has been brought tothe production level of the well and it is desired to open the valves a valve opener, generally indicated at i3, is lowered through the string of flow tubing to strike the knob E3 on the valve plunger forcing the plunger down and shearing the shear pin 85 to move the plunger from the valve closing position illustrated in Figure 4 to the open valve position illustrated in Figure 5.

This valve opener 'i3 is a body of metal having three angularly spaced, longitudinally extending blades or ns 'M joined at their inner edges to a central core. The lower end of this core is provided with a screw threaded well 'i5 into which is threaded the upper end of a valve operating pin 'i6 having a cylindrical shank and a cylindrical head on the bottom thereof somewhat larger than the shank. The upper end of the valve opener 73 is provided with a hollow, externally screw threaded cylindrical extension 11 engageable by a suitable wire supported tool to retrieve the valve opener from the ow tubing string when desired. It is not necessary for operativeness of the device however to retrieve the opener since the amount of iiuid flowing through the choke tube im will easily iiow through the spaces between the blades or iins 'i4 of the valve opener, and through ports between the blades lead into the hollow extension 11.

As illustrated in the modified form of the invention shown in Figure 9, the valve unit 5d may be substituted by a frangible disc 3@ secured on the upper end of the locking slip mandrel 43 by the internally flanged nut 55. In this case the valve opening pin l? at the lower end of valve opener 'i3 is substituted by an elongated pin Si having a substantially conical, pointed lower end 82 for rupturing the disc 30.

Any necessary amount of weight may be added to the valve opener to open the valve or rupture the frangible disc and as soon as the valve is opened or the disc broken the uid mineral, such as petroleum, will flow into the perforated nipple 31, through the choke tube 49, the packing mandrel lil, and the locking slip mandrel d3 into the lower end of the bottom section of the string of flow tubing.

Under certain conditions it is desirable to force fluid downwardly and through the ow tubing and into the space between the casing and the bottom end of the ow tubing to wash out or acidify the well, to dissolve precipitated matter, or force some or all of the material between the casing and the flow tubing string to the surface. This is accomplished with the device of the present invention by withdrawing the mandrel choke and valve assembly from the casing and upwardly through the ow tubing to the surface, removing the upper packing 28 and placing sleeve 83 in the location of the removed packing and then forcing the assembly back down through the flow tubing string to a position in which it is again locked in the casing l5. The sleeve 83, under these conditions, serves to center the vmandrels in the casing i5 and is provided in its inner face with angularly spaced openings 84 which permit fluid such as water, acid or solvent to flow between this sleeve and the packing mandrel and into the space between this mandrel and the surface of the casing bore from which it flows through the'ports 2| opening the spring closed valves 22. As thefluid flows through the ports 2l the annular deilector 25 directs the fluid downwardly to prevent damage to the well casing at this location.

Thus, with the device of the invention, the well may not only be iiowed without removing the column of fluid mud from the well and without having toremove any mud from the interior of the flow tubing, but fluid, such as water, acid or solvent, may be forced to the production level of the well also without interference by the mud column in the well.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments` are therefore to be considered in all respects as illustrative and not restrictive, the sc pe of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meanng and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A valve and choke assembly for flowing wells comprising a cylindrical casing adapted to be connected at' one end to the bottom end of a string of well flow tubing and having an annular internal shoulder adjacent said one end, a tubular packing mandrel slidably mounted in said casing and extending longitudinally thereof, a perforated nipple having a closed end and an open end secured at its open end to the end of said mandrel remote from said one end of the casing, a choke tube having a restricted bore therethrough threaded into the end of said mandrel to which said nipple is connected, a packing on said mandrel sealing the latter to the interior of said casing, a slip mandrel threaded at one end to the other end of said packing mandrel and having a conical surface intermediate its length tapering in a direction away from said packing mandrel, a slip carrier slidable on said slip mandrel, locking slips pivotally secured to said carrier and engageable with the shoulder in said casing by said conical surface to releasably lock said mandrels in said casing, a valve unit secured in the other end of said slip mandrel, and a anged nut threaded onto the other end of said slip mandrel operatively securing said valve unit to said mandrel, said valve unit being adapted to be opened by a valve opendiseases er lowered through a string of flow tubing to which said assembly is attached and striking the upper end of said valve unit.

2. A valve assembly for flowing wells comprising a hollow casing attachable at one end to the bottom end of a string of well ow tubing, a tubular mandrel assembly slidable in said cas ing, and a valve unit carried by said mandrel assembly adjacent said one end'of the casing and comprising a cylindrical housing received in said mandrel assembly at said one end thereof and having an internal fluid passage extending therethrough and a valve seat at the end thereof disposed inwardly of said mandrel as.- sembly, a plunger slidable in said housing and extending longitudinally therethrough, Said plunger having a valvegate on one end engageable with said valveseat to close said valve, a shear pin extendingv through said plunger and engageable with said valve housing to hold said valve plunger in valve closing position, said plunger being movable to valve opening position by a valve opener lowered through the now tubf ing string to impinge the top end of said valve plunger, and means carried by said plunger and engageable with said housing to lock said plung-l er in valve opening position relative to said housing.

3. A valve and choke assembly for fiowng wells comprising a tubular casing attachable at one end to the lower end of av string of well flow tubing, a tubular mandrel assembly slidably mounted in said casing, means releasably locking said mandrel assembly in operative position in said casing with one end of said assembly adjacent said one end of the casing and the other end of the mandrel assembly adjacent the other end of said casing, packing means between said mandrel assembly and said casing preventing the now of fluid therebetween, a tubular choke se-l cured in said mandrel assembly at said other end of the latter and having a restricted bore there,- through, a tubular valve housing secured in said mandrel assembly at said one end of the latter and having one end disposed inwardly of said mandrel assembly and provided with an annular valve seat, a valve plunger slidably mounted in said valve housing and extending longitudinally therethrough with one end extending outwardly of said one end of said mandrel assembly and having on its other end a valve head engaging said annular valve seat to close the valve, means connected to said plunger and releasably em gaging said housing and holding said valve in closed condition, said valve being opened by impingement of a valve opening weight on said one end of said valve plunger, and lock means connected to said valve plunger and engaging said valve housing when said valve is opened to main-- tain said valve in opened condition.

4. In combination with ay tubular casing attachable at one end to the bottom end of a string of well flow tubing and a. tubular mandrel assembly mounted in said casing and having one end adjacent said one end of said casing, a new controlling valve comprising a tubular valve housingxnounted in said mandrel assembly at said one end of the latter with one end disposed inwardly of said mandrel assembly and provided with an annular valve seat, a valve plunger extending slidably through said valve housing longitudinally thereof with one end extending beyond the other end of the latter for impingement by a valve opening weight and having on its other end a valve head engaging said valve seat to close the valve, means connected to said valve plunger and releasably engaging said housing and holding said valve in closed condition, and lool: means carried by said plunger and engaging said housing when said valve is opened to retain said valve in open condition.

y DERRIAL O. ROLLINS.

References Cited in the iile of this patent.

UNITED STATES PATENTS Number Name Date 1,920,103 Otis July 25, 1933 2,132,081 Nixon g Oct. 4, '1938 2,133,272 Coberly Oct. 18, 1938 2,144,850 Otis Jan. 24, 1939 2,152,794 Dripps Apr. 4, 1939 2,192,236 Nalley Mar. 5, 1940 2,241,439 Ball 1 May 13, 1941 2,246,811 Otis June 24. 1941 2,374,169 Boynton Apr. 24, 1945 2,401,119 Taylor May 28, 1946 2,431,751 Hayward Dec. 2, 1947 2,508,286 Otis May 16, 1950

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