US1594448A

US1594448A - Method of and device for cementing wells

Info

Publication number: US1594448A
Application number: US88076A
Authority: US
Inventors: Boynton Alexander
Original assignee: Individual
Current assignee: Individual
Priority date: 1926-02-13
Filing date: 1926-02-13
Publication date: 1926-08-03
Anticipated expiration: 1943-08-03

Description

. A. BoYN'rLoN METHOD 0F AND DEVICE FOR CEMENTING WELLS- Filed Feb. 13,

INVENTORl ATTORNEYS lill Il l |||||l||lL|||||lllrlllsrftrilnlnlll Alexander gyno,

Patented Aug.. 3, 1.9276. i"

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Application mea February 1:,1926. manl It. come; t

This'invention relates to a. method of and device for cementing wells.

The object of the invention is toprovide a method and device of this character which separates during passage of the cement into the well casing, which prevents the adherence of the cement to the well casing as well as the admixture of the cement with the mud fluid;

from the casing'to the oint of cementation and also prevents disp acement of the cement beyond the point where it is desired to apply the same; which has all of these ad.

vantages without necessitating manipulation of the well casing and without liability of any of thetparts of the device becoming stuck or jammed in the well casing.

ln carrying out the present invention the well casing 1s provided with cement d1scharge means pointtherein. Adjacent, and preferably just above'the cement discharge means, the casing is provided with a valve seat which may take any suitable form. A lower plug of soft pliable material adapted to snugly fit the casing and to be broken up when forced agaiustt casing above the mud iuid; that is, above the liquid employed to eiect circulation. Liquid cement is introduced into the well casing above the lower lug and on top of the cement an upper p ug of soft pliable material also adapted to snugly fit the casing and to be broken up when forced against the valve seat is intro uced into the casing. In the upper plug a relatively small and hard incompressible valve and indicator member, which may be in the form of a ball, isfimbedded and this valve and indicator member is adapted toco-act with the valve seat to close the bore of the well casing when the plug in which it is carried has been broken up. After the introduction of the upper plug into the well the well casing is cap ed and connected with thev pump-and mu fluid is forced` down lon top of the upper plug. The plugs ma any suitable soft and plia le material which is adapted to be broken up'` when forced against the valve seat under thepump pressure and preferably these plugs are constituted of silica gel, alumina gel or any other reasonably vrm gelatinous substance which the cement from the mud iuidwhich maybe located at any e valve seat, is introduced into the be constituted of is pliable though .substantially inelastic.'`

The advantage of the use of such plu is that they provide eiective packers an' yet are sufficiently deformable to permit them to ass dents and im erfections in the casing. oreover, these p ugs will notv swell and, stick or .jam in the casing although they isolate and separate the cement from the. mud iuid. The lower lug sweeps and'. scrubs the wall of the wel casing ahead of the cement so as to clean the wall of the mud fluid and also prevent the cement from being precipitated into the mud iuid. The top plug or the upper plug likewise serves as a casing sweeper and scrubber and not only 'serves to prevent admixture ofthe cement and mud fluid buttalso sweeps the cement oii' ofthe well casing and prevents the cement -from setting thereon. 4lfVhen all of the cement has been discharged the top or upper plug will be forced under the great pump pressure against the valve. seat and will be broken up. This will release ordisassociate the ball of the upper plug and pen mit it to engage the seat/to plug or close the bore of the well casing just above the po-int of cementation. The engagement of the ball valve member with the valve seat not only prevents Qdisplacement of the cement beyond the point of ap lication but also causes the erator that the cementing o eration has been completed. The combine indicator and valve member may be of any specific gravity.

"Whiley the plugs servev during their descent through the Well casing all of the puri poses of woodenvplugs in so far as isolation of the cement and mud fluid is concerned they arefree from the fatal objection of wooden plugs in that these gelatinous plugs are sufficiently yieldable and elastic to pass imperfections in the casing.

In order to enhance the packing action of pump to stall, t ereby indicating to the op- Athe plugs their upper ends may be provided with a recess of such a character as to permit the iuid dpsressure to expand the same. I The lower en of theplugs are tapered or pointed to permit them -topass or guide ,Y

themselves through obstructions Aor imperections inthe well casing. Af

Other objects and advantages reside iny certain novel features of the construction, arrangement and combination of parts which will be hereinafter more fully described and lparticularlyr pointed out in the l another embodiment ofthe invention, and

`Figure 3 is a detail vlew, partly in section and partly in elevation showing the up er plug. t

eferring to the drawings it will be seen that the cementing deyice is made up of a number of hollow cylindrical sections 1 and 2 coupled together b. means of a'coupling sleeve 3 which is loc ed to the section sfby` between# b means of keys 4 driven in coupling sleeve and the sections. In the form of the invention shown in y Figure 1, a set shoe 6 is threadedly con- 20 f indicated at 7, and islocked means of a number e suitably v short cylindrical portion 16 and carries a charge openings 21'* which have their otherwise suitably secured to blade nected to the lower end of the section 2, as to the section g of keys 4 which are ntical with the keys'4 except that they are longer.

Between the sections 1 and 2 the flange 8 of a valve seat 9 is clamped and such flange is held in position by means of lock screws 10 eo-acting with the coupling 3 andlwith the ange, as shown in Fi ure 1. The valve seat 9 has a conoidal portlon 11 and an o positely disposed conoidal ortion 12, t e

conoidal portions 11 and 12 eing connected .n by a short cylindrical portion Q 13 and in the conoidal ortion 12 a valve seat 15 is provided. T e ange-S is connected with the lower end of the conoidal portion -11 by means of a short cylindrical connectin portion 16. A spider 17 is integral with or connected to the flange 8 and to the back pressure valve, designated generally at 18. A second back pressure valve 20 is provided between the lower end of the section 2 and the set shoe 6 and the back pressure valve 20 is held against spinningby means of lock screws 21.

The section 2 is provided with cement disouter portions or walls countersunk to rovide valve seats. Metal valves 22 in the half spheres co-act with the valve seats and these metal valves 22 are spot welded or springlike carriers 23, the ends of which have slots 24 co-acting with headed-,pins 24l` fastened to the section 2. The spring carriers 23 are tensioned to hold the valves against their seats but under the influence of a certain predetermined degree of pressure exerted against the valves and the carriers, these spring carriers may be iiexed outwardly to ermlt discharge through the openings 21. utward lexure is permitted by virtue of the provision of the slots 24. This cement discharge means is fully shown, described well casing and orm of' and'claimed in co-pelidin application filed Dec. 21 1925, Serial No; 6,839.

A lower plug 25 of soft pliable and somewhat yieldable and elastic material is provided and hgsa body portion of cylindrical `form, a pointed or tapered lower end 26 and a conical recess 27 in its upper portion. The plug 25 snugly fits the well casing and also the section 1 which are incorporated in the which are of the samel size as the well casing. The plu 25 is interposed between the liquid cement and the underliing mud uid. Between the cement and t 'eibverlyin mud Huid an upper or top plug 30 is provi ed and also has a cylindrical ody, a pointed or tapered lower end 31 and a conlcal recess 32 at its upper end. The

plugs

25 and 30 may be constructed of any soft and pliable material having some slight degree of yieldability and elasticity and adapted to be broken up when forced against the" valve seat but preferabl the plugs are constructed of gelatinous' su stance such as alumina gel or silica gel although the plugs have sufiicient elasticity or yieldability to pass imperfections inthe casing they have not any material or substantial property of elasticlty and under the iniuence of .great pressure and when striking the valve seat readily become disintegrated or broken up. In theup er plug 30 a ball 35 of hard, noncompressi le substance is imbedded. ball 35 is relatively small with respect to the `well casing but as this ball is carried by and within the plug 30 the speciic gravity is immaterial. It may be of greater specific gravit than the cement or not as may be esira le or convenient. The valve v35 is adapted to coact with the valve seat 9.

-This device may be readily converted for use with one string Wells by omitting the set shoe 6 and the back pressure valve 20 and replacing these parts with a, couplin 40 and brass plate barrier -41 as shown in igure 2. In one string wells the liner 42 is suspended below the wellcasing 43 as shown in the drawing and it will be desirable to provide suitable formation packers, such as indicated at 44, below the cementing device and above the liner. i

The valve Seats are made of-soft brass or any other suitable material which may be easily `,drilled out after the cementation has been entirely completed.

In carryin ,out the method the-plug25 is first intro uced into the casing on top of the mud iiuid M. The plug 25 snugly fits the casingV and when the liquid cement L is placed on top of the plug 25 within the casing it is separated from the underlying mud fluid M by The means of this plug 25 because of the snug fit of the plug in the cas-- p capped and connected up to the pump mud fluid M is :forced down on top of the plug 3() and this forces the plug 30, the liquid cement L, plug 25 and mud flu-id `M down throu h the casing until the plug 25 strikes the va ve seat 9 when it is broken up or disintegrated whereupon the liquid cement ows through the openin of the valve seat `and out through the chec valve controlled cement discharge openings 21. When all of the cement has passed through the open`l ing of the valve seat the plug BOstrikes the valve seat and is disintegrated and broken up which permits the ball valve 35 to en-A gage the valve seat 9 and block or close the casing at this point, thereby preventing the mud fluid M from being pumped down through the valve seat and displacing the .cement beyond thel point desired. The

pumps stall at this time and advise the operator that the cementation has been completed. e

The advantages cf plugsare had without any of the disadvantages incident thereto. In other Words, the icement is separated andV isolated l from the mud fluid so that admixture is` prevented and the wall of the well casing is cleaned and scrubbed of .cef

ment which precludes the cement from setting thereon. Exce t for the upper plug 30 cement would ad ere to the casing and settle down upon ball 35 after same has seated. This plug 30 not only saves the cement for use outsidethe casing, but avoids having to drillit out when-set. Along with these advantages it is not necessary to manipulate the well casing and the sibility of plugs jamming or sticking in the casin is avoided.

l. The herein described method of cementing walls equipped with casing provided with cement discharge means which consists in providing avalve seat adjacent the point of discharge, introducing into the casing above the mud fluid a lower plug of soft, pliable material adaptedl to snugly fit the casing and to be broken up when forced against the valveseat, introducing cement into the casing above the lower plug, l

introducingl into the casing above the cement an upper plug of soft, pliable material adapted to snugly fit thefcasing and to be broken up when forcedV a ainst the valve seat and having imbedde therein a relatively small and hard valve member adapt# ed to enga e the valve seat when the plug which carries the same is broken up, and introducing mud Huid in the casing above the upper plug.

2. The herein described vmethod lof" cementing wells equipped with casing provided with `cement discharge means which posconsists in roviding a valve seat adjacent the point o discharge, introducin cement into the casing, introducing into t e casing above the cement a plug of soft, pliable material adapted to snugly fit the casing and -to be broken u vwhen forced against the valve seat and aving imbedded therein la relatively small and hard' valve member adapted to engage the valve seat when the plug which carries the same is broken up,

and `introducing mud fluid in the casing above the plug. v 3.' In the herein described method of cementing walls equipped with casing pro- 1 4. A cementing device for wells. compris-` ing a well casing having cement discharge means, a valveseat adjacent said discharge means, spaced; plugs of soft pliable material adallced to be broken up when forced against t e valve seats and snu ly fitted in the casing o n vthe opposite sies of the cement to preventadmlxture of mud fluid and cement and to prevent adherence of the -cement to the inner wall of the well casing,

and a relatively small and hard valve and',

indicator member imbedded in the upper plug and co-operable with' the valvev'seat when the plugs havebeen broken yup. f

' 5.v A cementing device for wells comprising a well casing having cement discharge means, a valve seat adjacent said dischar e means, spaced plugs of gelatinous materia adapted to be broken up when forced against the valve seats and snugly fitted in the casing on the 'opposite sides of the cement to prevent admixture of mud Huid-and cement to prevent adherence of the cement to the inner wall of the well casing, and a relatively small and hard valve and indicator member imbedded in the upper plug and co-operable with the valve seat when the plugshave been broken up.

6. A cementingdevice for vwells comprising a well casing having cement discharge means,la valve seat adjacent said discharge means, spaced plugs of soft, pliable material adapted to be broken up when forced against thevalve seats and snugly fitted in the casing on the opposite sides of the cement to Vprevent admixtureof mud uid and cement and to prevent adherence of the cement to having expansible upper ends forced against the casing by the pressure ofthe Huid abeve'k the same, and a' relatively small and hard valve and indicator member imbedded in.

1n I the cement to prevent admixture of mud' the upper lug and co-o 'rable with the valve seat w en the'plugs ave been broken4 p ""f j v Y e 7. A cementing device for wells com- 5 prisingv a. well casing havingcement 'd1scharge means, a valve seat adjacent said discharge mea'ns, spaced lugs of soft,'pl1able material adapted to broken up when forced against the valve seats and snugly fitted in the casing on the opposite sides of Huid-.and cement and-to prevent adherence Aof the cement to 'the inner wall of the well casing, said plugs having recesses in their l5 forced into pac upper ends adaylitl-ing the upper ends to be 'ng engagement with the casing, and a relatively small and hard valve and indicator member imbedded in the vupwhen t e plugs have been broken up.

' 8. A vcementing device for, wells com prisinga well casing having` cement discharge means, a valve seat adjacent said discharge means, spaced plugs of soft,` pliable material adapted to e broken up when 'forced against the valve seats a'ndvsnuglyl fitted in the casing on the opposite sides of the cement to prevent admixture of mud fluid and cement and to prevent adherence of casing, said plugs having pointed lower ends to facilitate movement 'of theplugs" down.

per plu and co-operable with the valve seatl and having packing the cement tothe inner .wall of the well' through the casing, and' `a `relativel and hard valve and indicator mem r im-l bedded in Athe upper plug and co-operable been broken up.4 v c 9. A cementing device .for wells comf pris1ng` a well casingY having cement discharge means, a valve seat adjacent said discharge means, spaced plugs of soft, li` able material adapted to be broken up w en forced against the. valve seats and snugly fitted in the casing on the opposite sides of the cement to prevent -admixture .ofmud fluid and cement and to prevent adherence of with the valve seat when the plugs `have the cement to the inner wall of the well 'and a relatively small ,and hard indicator and valve member carried by the upper plug and co-operable with 'the valve seat when disassociated from its plug.V

ALEXANDER BoYN'roN.