US2092041A

US2092041A - Apparatus for sealing off the strata in a well bore

Info

Publication number: US2092041A
Application number: US29989A
Authority: US
Inventors: Arthur L Armentrout; Elwin B Hall
Original assignee: SECURITY ENGINEERING CO Inc
Current assignee: SECURITY ENGINEERING Co Inc
Priority date: 1935-07-05
Filing date: 1935-07-05
Publication date: 1937-09-07
Anticipated expiration: 1954-09-07

Description

Sept. 7, 1937.

A. L. ARMENTROUT ET A1.y 2,092,041 l A' APPARATUS SEALING OFF THE STRATA IN A WELL BORE Filed July 1935 2 sheets-sheet 1 giga f 0 Sept. `1937. A A. 1 ARMENTRQUT ET, AL y l24,092,041

APPARATUS FOR SEALING OFF` THE STRATA INA WELL BORE Filed July S, 1955 k2 ySheets-Sheet 2 Patented Sept. 7, 1937 Wi, s:

APPARATUS Fon'sEALING oFF THE STRATA 1N `il WELL Bons Arthur L. Armentrout, Bakersfield, and Elwin B. Hall, Los Angeles, Calif., assignors, by mesne assignments, to `Security Engineering Co., Inc., Whittier, ,(lalif., a. corporation of y California applicati@ 'July/"5, 1935, serial No. 29,989`

5 claims.

This inventionjrelates to a method and apparatus for lexcluding encroaching fluids from a Well* A general object of this invention is to provide a rapid, practical and inexpensive meth- 5 od for sealing or shutting oil water ornotherunf desirable fluids from ,a Well and to provide a simple, practical and effective apparatus for carrying out said method.

In the drilling of deep wells'such as oil wells` l and gas wells, the bore often penetrates strata bearing water and/or water withv a small por-` It` is usually necessary tion of oil and/or gas. to exclude these undesired encroaching fluids from the well. For example, where a water sandy lor a stratum bearing water is located either above or below a productive oil orv gas stratum f in relatively close proximity thereto, it' is desrable to exclude or seal ofi the water from the Well without sealing ofi the `'productive stratum' 20 or strata. Heretofore much difficulty hasbeen encountered in excluding or sealing oi encroachy ing fluids from wells.

An object of thisl invention'is to provide a simple method by `meansofwhich encroaching fluid or a liner or other subsequent operations'. Upon the completion of the method of thepresent invention the ywater or encroaching iiuid` is fullyv 3 and dependably sealed from the well and the well tions of the bore.

Another object of this invention is toprovide' 4 a method for excluding vfluids from a Wellthat fere with'or obstruct subsequent operations.- Another'y object of this invention is to provide a method for sealing water and the like :from

v 45 deep wells that may be employed to seal off.

vthe encroaching fluid at any point in the open wellbore as required, and that may be employed to seal leaking casing.

Another object of this invention is -to provide 50 a method o'f the character mentioned that may be easily [and quickly carried out with a minimum number of simple operations.

` Another object of this invention is to provide apparatus useful in excluding encroaching fluids 5 irom a well that comprises a frangible or friable sequent passage of tools, the setting of casing 'rhas entered the well bore.

,and below the stratum S may be considered as shale, or the like, while the stratum B below the bore at that point is clear and unobstructed, being of the same diameter as the adjacentl por-l doesnot necessitate the setting of metal casing, metal liners or other metal parts likely to inter' member that may be drilled from the well when the' water bearing sand has been cemented oi leavingthe well bore entirely clear'and' unobstructed.

' Another object of the invention is to provide apparatus useful in excluding fluid-from a well that assures the proper placementl and'idistribution of the sealing cement.

A further object of the invention is to provide an apparatus for use in excluding water or other fluid from a well-that is very simple and inexpensive of manufacture.

'The various objects andfeatures of the invention will be fully understcodfrom-the following detailed description of va typical manner of carrying out the method and a typical form 'of the invention, throughout which description reference is made to the accompanying.'

' at the point of entrance of fluid .to the well. Fig. V2 is a view'similar to Fig. il illustrating the friable member and its baskets in positionto re- Vceive the cement. Fig'. 3 is a view similar toFig. l2 showing the cement filling the "member and expanding the baskets to occupy'the enlargement ortcavity and Fig. 4 is a view similarfto Fig. 3 illustrating a 4drill'drilling out` the friable memf-ber and the excess cement in the well.

In the drawings the well bore B passes'through or.v penetrates a stratum S that bears water or otherl undesired iiuid which is entering or which The vstrata A above lower stratum A may be considered as a productive sand bearing oil or gas, or both. y

,. present invention will be better understood after reference has-been made to the apparatus employed in performing or carrying `out the method. Accordingly wewill proceed with a detailed description of a typical embodiment of the apparatus and will then describe rthe method as carried out in employing the apparatus. The apparatus provided by the invention and employed in carrying out rthe method of the invention includes, generally, an underreamer IU for enlarging the well bore B at the stratum S,

va tubular string II adapted to; berun into the well, a drillable or friable perforate member I2 detachably connectedwith the lower eridof the stringk I I, a basket I3 on the member I2 to receive cement for filling the enlargement or cavity C made by the underreamer I0, and a drill D for drilling up the member I2 and the cement re' maining therein and remaining in the well bore 5 proper following the setting of the cement.

The invention contemplates the employment of any desired form or type oi underreamer for making the enlargement or cavity C in the well bore at the water bearing stratum s. It is preferred to employ an underreamer capable of making an enlargement or cavity C considerably larger in diameter than the well bore B. The particular underreamer III illustrated is intended merely to be illustrative of a typical tool of this l5 class and includes a body I4 carrying a plurality of cutters I5 mounted to expand or move outwardly. As shown in Fig. 1, the cutters I5 are in their expanded positions. The underreamer bodyl I4 is attached to the lower end of a drilling string. or operating string IB and the underreamer is operated by rotation of the string in the usual manner. Before running the underreamer I0 into the well it is preferred to definitely locate the stratum S bearing the water or encroaching fluid. 'I'his location of the stratum S may be accomplished by any of the well known methods. It may be preferred to carry or extend the cavity C beyond the upper and lower limitsof the stratum S, as illustrated through- 3 out the drawings. After forming the cavity C the cutters I5 are retracted and the underreamer is removed from the well bore on the operating string I8. Y

The string II is provided to run the friable member I2 into the well and to conduct the cement to the member. In accordance with the invention the string Il is tubular and may be made up of a plurality of lengths of pipe or tubing.

'I'he member I2 is an important feature of.

the present invention. The member I2 is an elongate part proportioned to be received in the well bore B with suitable clearance. The friable member I2 is preferably suiiiciently long to extend beyond the upper and lower limits of the cavity C when in its proper position or location in the well bore B. A longitudinal opening I1 enters the member I2 from its upper end and extends to a point adjacent the lower end of the member. The lower end of the opening I1 is closed and a tapered or rounded nose I8 is provided on the lower end of the member to guide it ln the well boreA B. The upper en'd I9 of the member I2 is preferably tapered downwardly and inwardly for the purpose tolbe hereinafter described. In accordance with the -invention the member I2 is releasably connected with the lower end of the string I I to have its opening I1 in communication withthe opening of the string. In practice the member- I2 may be releasably connected with the string I I in any suitable manner or by means of any suitable device; for instance, by a releasable adapter, a safety joint, or by left hand threads 2li as illustrated in the drawings. The threads 20 being left hand threads may be easily released or unthreaded without loosening the usual right hand threads4 in the string II. The invention provides a plurality of circumferentially and longitudinally spaced ports 2i in the wall of the member I2. It is a feature of the present invention that the member I2 is drillable or friable being formed of cement, Bakelite, hard and brittle rubber composition, glass, ceramic material, or any other material that may be readily broken up or drilled up by drilling aocaon tools. Owing to the fact that the member I2 is encased in cement when it is to be drilled up it may be desirable to form the member I2 of cement, it being understoood that the member may beformed of any material that is readily drilled up, as just described.

In the preferred form of the invention illustrated means is provided-for preventing a reverse or upfiow of cement from the opening I1 to the string II and to prevent the loss of pressure on the cement in the opening I1 and the cavity C. I have shown a check valve arranged in the upper portion of the opening I1 to prevent the reverse flow of cement and the loss of pressure on the cement. The particular check valve illustrated includes a seat 22 arranged across the upper portion of the opening I1. 'I'he seat 22 is frangible or friable, being formed of cement, or the like, and is provided with a central opening 23. A ball 24 is provided to seal upwardly against the seat 22 to close its opening 23. The ball 24 may be formed of hard rubber or a suitable composition. A cage is provided to hold the ball 24 when in its open position. The cage may comprise wires 25 having their ends embedded in the seat 22 or the menber l2. 'I'he ball 24 is adapted to seal upwardly against the seat 22 by internal pressure in the opening I1.

The basket I3 is provided to receive the cement asit discharges from the ports 2| and is operable to expand into the cavity C by the internal pressure of the cement to hold the body of cement in the cavity C and prevent its loss longitudinally in the well bore. The basket I3 includes a main skirt or main basket part 26 surrounding the member I3 and extending throughout the perforated portion of the member. The main basket part 26 is preferably formed of rubber to be expansible or ii' desired the part 26 may be formed of canvas, in which case it is initially pleated to be expansible. 'I'he lower end Portion of the basket part 26 closely embraces the member I2 at a point below the lowermost ports 2l. A band 21 or other means may be employed to hold the lower end portion ofthe basket part 26 in tight engagement with the external surface of the member i2 so that it is closed against the leakage of the cement.V The main basket part 26 extends upwardly some distance beyond the .uppermost ports 2 I.

The basket I3 includes an upper apron or skirt 28 which extends into the upper end of the main basket part 26. By this arrangement the basket I3 includes two overlapping or telescoping basket sections making it such as to readily expand and conform with the bore into which it is forced. 'I'he skirt 28 may be formed of rubber or canvas and is adapted to expand outwardly as the basket becomes filled wth cement. It is preferred that the skirt 28 extend downwardly a considerable distance into the main basket part 26 .to prevent the upward escape of cement from the `interior of the basket. A band 29 or other means may secure the upper end of the skirt 28 to the member I2. A plurality of spaced openings 30 may be provided ln the main basket part 26 to discharge a limited amount of cement into the stratum S in the event that the stratum S is porous to absorb the cement. The openings 30 are preferably spaced a considerable distance fromthe opposite ends of the basket to prevent the leakage of the cement into the well bore B.

The drill D is employed to drill up the friable member I2 and the cement remaining within the member I2 and surrounding the member in the well bore proper following the cementing operation. The invention contemplates the employment of any suitable form of drill for drilling up the iriable member I2 and the excess cement 5` remaining in the well bore. `It may be foundfdesirable to employ a pilot bit or a diamond point bit of the type illustrated which is operable to Y first enter the projecting upper end of the member I2 and then cut away the member and the l excess cement as it is fed downwardly.l The diamondpoint drill D illustrated. in the drawings is adapted to berun into the well bore on` an operating string or drilling string` 32. The drill D has a pointed lower end 33 having downwardly 15 `and inwardly inclined cutting edges 34. The i drill D has the usual. discharge ports 35 for the discharge of the circulation uid during' drilling.

It may be preferred to employ a drill D having an eilective diameter equal to the diameter of the 20 well bore -B so that it is operable todrill out all the cement in the Well bore proper leaving the bore clear and unobstructed. i

It is believed that the operation of the apparatus will be readily understood from the following detailed description of the method of the present'invention as carried out with the apparatus. The method of this invention as practiced with the apparatus described above includes, generally, forming an enlargement or cavity C in the wall of the well bore B at the stratum S bearing the encroaching iiuid, positioning a perforate friable member I2 and a cement basket I3 in the well bore B at the cavity C, passing or delivering cement 40 to'the member I2 and the basket I3 to expand thebasket and illlr the cavity C, allowing the cement 40 to set, and then drilling out the friable member I2 and more or less of the cement in the well bore B to leave the desired size of bore and to leave 40 a shell or lining 4I of cement in the cavity C to shut oi theencroaching nuid from the well bore.

'I'he forming of the enlargement or cavity C may be readily accomplished by the underreamer I0 or by an equivalent tool. The underreamer I0 45 is run into the well bore B on the string I 6` to the previously located stratum S and the string is operated to expand the cutters I5 and is then rotated and fed downwardly so that the cutters I5 form the cavity C. It is preferred to extend 50 the cavity C beyond the upper and lower limits of the stratum S so that the lining 4I of cement is anchored in the hard strata A. Following the forming or drilling of `the cavity C the underreamer I0 is withdrawn from the well bore on the 55 operating string I6.

Following the drilling of the enlargement or cavity C in the wall of the well bore B the friable perforate member I2 is run linto the well on the string I l to a position such as illustrated in Fig. 2

80 of the drawings. The member I2 is attached to lthe lower end of the string II by the left hand threads 20 or other suitable connecting means and the string I I is run into the well in the usual `-manner to properly position the member I2 in 65 the well bore Where it extends through the cavity C to project beyond the upper and lower extremities of the cavity. Afterthe member I2 has been positioned the invention provides for the delivering of cement to the member to expand its basket 70 I3. The cement may be delivered or passed to the member I2 by means of any of the well known methods, for example, the cement may be delivered to the member I2 in a drop bottom bailer or by the Perkins method. It is preferred to 75 pump the cement into the member I2 or put the cement under pressure so that it flows through the ports 2| into the basket I3 under a suitable pressure. The cement readily passes the check valve 24 and then flows through the opening I1 to pass out through the ports 2I into the basket.

The cement under pressure entering the basket I3 expandsthe main basket part k26 and the skirt 2B. The basket part 26 and the skirt 28 are expanded outwardly until they bear with pressure against and conform to the walls of the cavity C. In the event that the stratum S is porous the cement passes out through the openings 30 into the stratum. A sufiicient quantity of cement 40 is delivered to the member I2 to fully `expand the basket I3 against thewalls of the cavity C and rto flow into thestratum S until the stratum has absorbed suicient cement. It is preferred to employ a quick setting cement so that the body of cement in the basket and encasing the member I2 will quickly harden or set. When the basket I3 has been properly expanded and the stratum S lled with cement until it no longer absorbs the cement, the pressure may be removed from the cement allowing the valve 24 to close against the seat 22. The cement that may remain in the string II is then removed as by bailing. The valve 24 closed against the seat 22 maintains the pressure on the body of cement 40 and prevents the upflow of the cement into the string I I. Following the cementing operation the string II is released from the member I2 and withdrawn from the well bore. The cement 40 is then allowed to set or harden.

The final step of the method is the drilling up of part or all of the frangible member I2 and the cement remaining in the well bore proper. This may be readily accomplished'by any suitable form of drilling tool. It is preferred, however, to employ a rotary drilling tool so that the body of cement 40 is not shattered. In most instances it may be preferred to employ a pilot drill or a diamond point drill of the type illustrated. A pilot drill or the diamond point drill D first enters Ythe opening I1 of the projecting upper portion of the member I2, The tapered upper end I9 of the member I2 guides the entering end 33 of the bit into the opening I1. As the bit or drill D is rotated and fed downwardly it drills away the friable member I2 and the cement 40 within the member and the portion of the body of cement immediately surrounding the member. When the drill D is of the same eil'ective diameter as the adjacent portions of the well bore B it drills an opening 42 in the body of cement 40 of the same diameter as the well bore, leaving a lining or sleeve 4I of cement in the cavity C which fully shuts oil' the iluld in the stratum S. The drill D is capable of drilling out the entire member I2 and the excess cement 40 in the well bore forming an opening 42 of the same diameter as the well bore B. The basket part 26 and the skirt 28 in being formed of rubber or canvas are readily cut or drilled away by the drill D without endangering the cement sleeve 40 occupying the cavity C. After the drill D has drilled through the body of cement 4I! and has fully drilled away the frlable member I2 it is removed from the well bore on its operating string 32 leaving the well bore clear and unobstructed for further operations. The

cement lining or sleeve 40 left in the cavity C effectively shuts or seals off the undesired fluid of the stratum S from the well bore B.

The apparatus and method provided by the present invention is adapted to be employed for sealing leaking well casing. When employed for n 'we this purpose the member i2 with its basket i3 may be substantially as described above and is positioned in the casing at the point of leakage.

The inside Wall of the casing atsaid point would i correspond to the bore at C, above described, except that it would not ordinarily be in the form of a cavity. Cement is then delivered or passed to the member I2 through the string I I to expand the basket i3 and pass out through the openings 3G. The cement leaving the openings 30 enters the crack or opening in the casing and possibly the opening behind the casing to seal the same. The cement is preferablypumped into the member i2 or put under pressure and when a proper quantity of the cement has discharged'into the basket I3 the pressure is removed from the cement and the string` ll is detached from the member I2 and Withdrawn from the Well bore.vr

The cement is then permitted to harden or set; After the cement has set, themember I2 and the excess cement remaining within the `casing is drilled up by means of a suitable drilling tool leaving the casing clear and unobstructed. The cement which will have entered the opening in the casing effectively seals the casing against leakage.

Having described only a typical preferred form of the apparatus and a typical manner of carrying out the method of the invention, we do not Wish to be limited or restricted to the specific details set forth, but Wish to reserve to ourselves any changes or variations that may appear to those skilled in the art or fall within the scope of the following claims:

Having described our invention, We claim:

1. Apparatus of the character described including, an integral drillable tubular member closed at its lower end and adaptedto be run into a Well, the member having a longitudinal opening and longitudinally spaced lateral ports, and a tubular basket surrounding the member to receive cement from the ports. l

2. Apparatus useful in excluding encroaching "duid from a well including a drillable member adapted to be run into the Well on a string, the member having a longitudinal passage for conducting cement from the string and a plurality of longitudinally spaced lateral ports communieating with the passage, a valve in the passage above the ports for preventing reverse now of the cement, and a basket on the member for receiving cement from the ports and expansible by the cementto occupy a cavity in the Well IWall, the member being drillable to be drilled up after setting of the cement.

3. Apparatus useful in excluding encroaching fluid from a well including, an integral drillable member adapted to be run into the Well on a tubular string, the member having a longitudinal opening communicating with the string and a plurality of vertically spaced lateral discharge ports, and a basket on the body adapted to receive cement from said ports to be expanded thereby into a cavity in the Well Wall, the basket including telescoping oppositely extending expansible skirts surrounding the body, the member being drillable to be drilled up after setting of the cement.

4. Apparatus useful in excluding encroaching iiuid from a well including a drillable member adapted to be run into the Well on a tubular string, the` member having a longitudinal opening for receiving cement under pressure from the string and longitudinally spaced ports for dis- ,harging the cement, and a basket on the memoer for receiving the cement from the ports and expansible into a cavity in the Well Wall by the cement passed into it, there being openings in the basket to discharge cement into the earth formation, the member being drillable to be drilled up after setting of the cement.

5. A device of the character described comprising, a cast drillable member having a longitudinal opening entering its upper end and longitudinally spaced lateral discharge ports extending outwardly from said opening, the member having an integral wall closing the lower end of the opening, an expansible basket on the member for receiving cement from the ports, and a valve at the upper end of the passage for preventing a return flow of iiuid therethrough.

ARTHUR L. ARMENTROUT. ELWIN B. HALL.