US2374317A - Well production equipment - Google Patents

Description

April 24, 1945. K. AI WRlGHT 2,374,317

WELL PRODUCTION EQUIPMENT Filed Dec. l0, 1940 2 Sheets-Sheet l lkl pri 24, 1945. K. A WRlGHT 2,374,317

WELL PRODUCTION EQUIPMENT Filed Deo. 10, 1940 2 Sheets-Sheet 2 @ai 4 ,f

2'? v mi l.

Arrows/fn Patented Apr. 24, 1945 UNITED STATES PATENT OFFICE WELL PRODUCTION EQUIPMENT Kenneth A. Wright, Los Angeles, Calif.

Application December 10, 1940, Serial No. 369,389

(ci. 16e-1s) Claims.

This invention relates to well production equipment, and particularly pertains to inventions of the general type shown in my (zo-pending application entitled Method and means of conditioning the walls of well bores, Serial No. 291,027, filed in the United States Patent Office by me on August 19, 1939, and is a continuation in part.

In preparing oil wells for production it is often necessary to set a perforated or flank casing in the well, and it is also common practice to cement casing in position within the well bore. In order to do this the casing is lowered into the well and is cemented in place 1by circulating the cement slurry downwardly through the casing and then upwardly within the well bore and around the casing. The cement is intended to ll the space Ibetween the casing and the walls of the well bore and to form a suitable 'bond with the side walls of the Well.

It has been found in actual practice that mud remaining on the walls of the well bore after drilling operations is often responsible for cemcnting failures due to the fact that the uid which is circulated ahead of the cement, or the cement itself, will not eiectually remove the mud cake. The presence of mud cake on the walls of the well bore causes channeling and also prevents the cement from completely filling the annular space between the wall of the well bore and the casing to form a bond between the actual wall of the bore and the casing. The mud cake left on the wall of the hole during cementing of a casing. or the like. is often the cause of weakness which may result in failure of the cementingr operation. This failure to obtain a Fbond as described, and also the channeling, may be responsible for failure to effectively separate or isolate one stratum from another and thus result in comt mingling of fluids or gas contained in such strata.

In order to obtain an effective cementing of the casing it is necessary that the bond of the cement with the well bore shall be continuous from the bottom of the casing to the top of the cemented area. It is also necessary to form a continuous cementing bond behind the casing in any given strata and a failure of the cement may result in undesirable leakage and in allowing water to invade the producing zones. This failure may also create high gas oil ratios or the flooding of producing zones by water. In order to obtain the most effective cemcnting of well casing within a Well bore it is desirable to insure that uniform distribution of cement is made around therasing and between it and the wall of the well bore, and that uniform lbonding of the cement to the wall of the well bore is obtained.

When it is desired to produce a Well through a perforated casing which is placed in the Well, the mud cake left on the wall of the Well bore may retard or prevent the oil and/or gas or fluids in the strata from entering the perforated casing. It is desirable to remove this mud cake from the wall of the well bore prior to putting the well on production. To do this the mud rcake must be abraded and loosened from the wall of the well bore and then fluid must be circulated to carry the loosened material from the hole. To accomplish this it is desirable to attach an a-brading member permanently to the perforated casing, which casing and abrading member remains within the well after the removal of the mud cake has been completed. Movement of the casing and abrading member may take place either up or down within the bore or 'by rotation of the casing. Attention is called to the fact that under normal well conditions when a well is being drilled 0r a casing set, the well is filled with drilling fluid. This drilling uid carries an appreciable proportion of suspended solids which tend to settle out of the suspending liquid and to deposit on the Wall of the well bore in a sheath. When various devices have been used heretofore'to ream the wall of a well it has been necessary to remove those devices by withdrawing the complete assembly from the well before a well casing could be set. In such instances it will be appreciated that not only will the loosened material tend to accumulate in the bottom of the well Ibut that also the drilling uid standing in the well will cause an additional sheath or layer to form on the wall of the well during the time the reaming assembly is being removed and the time while the permanent casing structure is being lowered into the well. It is therefore desirable to provide a device which will permit the wall of the well to be conditioned rapidly just as the casing is being set without the necessity of an elapsed period of time occurring within which a new sheath of material may accumulate on the Wall of the well to defeat the very purpose sought to fbe obtained when the wall was scraped.

It is the principal object of the present invention, therefore, to provide a means of conditioning the wall of the `well bore rapidly so that cementing operations can `be aided and so that by removing the mud cake the exposed strata behind the perforated casing in the well may produce its contained fluid and gas freely and permit a casing to be promptly set before a new vsheath of mud accumulates on the wall of the well bore. It is also an object of the invention to provide means i or centering the casing in the well 'bore so that uniform spacing will occur around the casing, the said method being simple in its performance and embodying the use of an inexpensive and easily operable means for accomfplishing the same.

Another object of the invention is to provide a unit or device for abrading the wall of a well bore and for centering a casing in the bore, which is characterized by novel spring elements anchored to the body of the device in such a manner that they may flex and work during operation with little or no danger of failure or detachment. 'Ihe spring elements are of novel shape to be effective in the ab'rading of the well wall and in centering the casing in the well bore without gouging into the earth formation and without becoming caught. 'I'he securing or anchoring means for these spring elements is such that extensive integral shanks of the elements are subjected to a mild torque action when the elements are in operation, the torque being distributed along the Shanks for a substantial distance so that there is no danger of permanent distortion or fracture.

A further object of this invention is to provide abradingv and casing centering devices of the character referred to that are sturdy and dependalble and yet are simple and inexpensive to manufacture. 'I'he low cost of the albrading units allows the employment of an adequate number well cementing operations, the abrading operation to be. accompanied by the circulation of a desired fluid to remove or flush out of the well bore the abraded and loosened mud cake. This fluid may be any suitable fluid, such as water, oil, acid or alkaline solutions, or water treated with desirable reagents, such as chemicals for reducing surface tension. which chemicals are known as wetting reagents.

The invention is illustrated by way of example in the accompanying drawings, in which:

Figure 1 is a vertical section of a well showing a casing and device of the present invention in elevation therein with la portion near the lower end broken away to show in section.

Fig. l* is a sectional view similar to a portion of Fig. 1 showing a slightly modified form of the invention.

Fig. 2 is an enlarged view in transverse section as seen on the line 2--2 of Fig.' 1, and discloses the manner in which the casing is centered in the well bore by the device of the present invention.

Fig. 3 is an enlarged view in side elevation showing one of the spacing and abrading units provided by the invention in |place on a casing and with a portion broken away to show in section.

Fig. 4 is an enlarged fragmentary view in section and elevation as seen on the line 4-4 of Fig. 3, showing the construction of the guide unit.

Fig. 5 is an enlarged fragmentary view as seen on the line 5-5 of Fig. 3 showing the crosssectional formation of the ribs.

Fig. 6 is a view in perspective showing one of the spring guide and cleaning elements of the unit provided by the invention.

Referring more particularly to the drawings. I0 indicates a well bore. Positioned within the well bore is a string of casing II. This casing may be perforate (as shown in Fig. 1 where it is designated as II), or imperforate (as shown in Fig. l), as required, and may be fitted with a lplurality of cleaning and guide units as generally indicated at I2. It will be seen that' these units I2 may be spaced from each other throughout a selected length of the casing, and-'that they act to position the casing centrally ofthe well bore I0. l

'I'he lower end of the casing II is provided with a suitable guide shoe I3.

Where the casing IIi is perforated or in the nature of a screen as shown in Fig. ll, a removable wash pipe 30 is lprovided to conduct fluid therethrough. The wash pipe 3U extends longitudinally through the casing to the shoe I3 so that the fluid is conducted downwardly to the shoe for discharge into the well. A cleaning and centering guide is shown in detail in Figs. 2 to 4 of the drawings. Here it will be seen that each unit comprises an inner sleeve I4 secured on the casing II and around the circumference of which are mounted ribs I5. The ribs I5 extend longitudinally of the sleeve and are secured at their opposite ends to the outer circumferential face of the sleeve. By reference to Fig. 3 it will be seen that the opposite ends of the ribs, as indicated at I6, lie iiat against the circumferential face of the sleeve and may be spot welded in place. The major portion of each rib, as indicated at I1, is of angle section, having an outer portion I8 parallel to the outer circumference of the sleeve and an inturned portion I9 standingV substantially radially with respect to the sleeve. The intumed portions I8 are formed with a plurality of recesses 20 which are spaced apart lengthwise of each rib and form guide seats for the shanks 2l of the cleaning and spacing iingers 22.

The spring finger structure is shown particularly in Fig. 6 of the drawings. Here it will be seen that the shank portion 2l is arcuate and as'indicated in Fig. 4 conforms to the outer circumference of the sleeve I4. At one end of the spring element 2I the finger 22 occurs. 'Ihis 'finger is arranged or shaped to assume a radial position with relation to the circumference of the sleeve. 'I'he length of the finger 22 is greater than the width of the annulus or space 23 which occurs between the casing II and the wall of the well bore I0. An upturned end part 24 is provided on the outer end of each finger 22 to act on the wall *of the well. 'I'he shank 2| and the finger 22 are formed integral from a continuous piece of round stock spring material. The end of the spring shank portion 2I opposite from that onwhich the finger 22 occurs is bent outwardly, as indicated at 25, and extends through a perforation 26 in the portion I1 of a rib beneath which it terminates. The extending portion at 25 'is "riveted over" so that this end of the spring shank 2| is held in position.

By reference to Fig. 4 it will be seen that each spring shank 2I is of substantial length. By reference to Fig. 3 it will be seen that the spring and finger elements 'are arranged in spiralled or helical sets, the fingers 22 being disposed radially of the sleeve and spaced consecutively around the sleeve in equal spaced relation to each other. The consecutive ngers 22 with their spring shanks 2| are disposed in separate horizontal planes as determined by the spacing and number of perforations 20. Each set of springs and fingers lies along a helix line extending substantially from one edge to the other of the sleeve I4 and across the width thereof. In the present instance ve sets of springs are shown as thus arranged. The formation, proportions and mountings of the spring insure that the spring ngers 22 will universally adapt themselves to the surface of the well bore, whether in a cleaning or spacing operation.

It is to be understood that since the spring fingers 22 are all of the same radial length their outer ends when unflexed terminate an equal distance from the sleeve. Attention is also directed to the fact that since the arcuate spring shanks 2| extend for a considerable distance around the circumference of the sleeve they extend beneath a plurality of ribs |5 and seat within a plurality of the recesses 20 in these ribs. Thus the springs are each held at a plurality of points to properly support the spring shank 2| and their ngers 22 during a time when the spring iingers are being flexed, It will he further seen that since the ends of each of the spring portions 2| are anchored by their extensions 25 the spring may be subjected to fa suitable torque action while allowing swinging of the spring lingers longitudinally of the sleeve.

In operation of the apparatus here disclosed and a typical method to be practised the cleaning and centering guide units l2 are iixed on the casing in spaced relation to each other along a desired length of the casing. This length of casing should normally represent the thickness of strata including the producing formation and the area in which cementing operations are to be carried onv The units l2 are proportioned so that a circumferential line including the ends of the spring iingers 22 has a diameter somewhat greater than the inside diameter of the well bore so that as the casing is lowered into the hole the spring ngers frictionally and yieldingly engage the walls of the well bore, and ilex upwardlv as the casing moves downwardly. The strength of the spring fingers is such that the collective action of the guide units tends to center the casing in the well bore. It is desirable to mount the guide units l2 permanently on the casing or well screen as the case may be. The casing is lowered into position in the well and then reciprocated and/or rotated within the well bore for any desired distance, such for example as a distance lgreater than that occurring between adjacent guide units. As previously explained. when the casing is moving downwardly, the fingers 22 flex upwardly and the curved ends 24 ride along the wall of the well bore while centering the casing. When a lifting. lowering or rotating action is produced the ends of the fingers 22 frictionally engage the well bore, and these fingers tend to iiex so that the end points of the portions 24 scratch the walls of the well bore. This is effective in removing the mud cake. and since the various ngers 22 of each guide unit are arranged in staggered relation to each other the wall is simultaneously engaged in different planes so that a thorough abrading action is effected. During this operation circulation is maintained to flush the loosened material from the Well.

Where the casing is imperforate, as shown in Fig. 1, the fluid is pumped down through the casing and discharges from the shoe I3 to flow upwardly through the annulus 23 to the ground surface. When the casing employed is perforated, as shown in Fig. 1a, the uld passes down through the wash pipe 30 to discharge into the well at the shoe I3 and returns upwardly through the space between the casing Il and the well wall. The uid thus circulated through the well serves vto carry away the solid matter or mud cake that is being removed from the well wall by the abradingunits |2, serves to wash or clean the well wall and operates to prevent'the mud from re-depositing or re-forming on the abraded well.4 wall. The character of the fluid employed at this stage of the operation may vary with the operating conditions. In most instances the fluid employed may be clean water or oil but, in other cases, it may be desirable or necessary to employ an acidizing solution or a solution containing a wetting agent. The fluid may be circulated during the entire abrading operation to carry away the major portion of the mud or material removed from the well wall by the units I2. The wash pipe 30 is withdrawn following the abrading .and circullating operations and prior to producing the we l.

When imperforate casing is being set, landed or cemented, the abrading and the circulating operations are celrred out simultaneously as above described. As the abrading operation continues cement slurry is usually substituted for the circulating or mud iiJuid, that is, cement slurry is passed down through the casing and discharges from the shoe |.3 to occupy the annulus 23 throughout a selected portion of the well. The abrading action may be continued during the delivery of the cement slurry to assure the direct intimate contact of the cement slurry with the virgin earth formation.

It is to be observed that the guide members |2 sustain the casing in a position concentric with the well bore so that a uniform thickness of cement is provided around the casing and the cement fills the annulus of the well bore to a selected level and bonds directly with the clean native formation penetrated by the well bore. When the cement is set it will be evident that the well casing, together with the guide units |2, will be held in the well permanently by the cement, and that the presence of the guide units including the plurality of fingers 22 imbedded within the cement will insure a thorough bond and union between the cement and the well casing.

From the foregoing it will be evident that the following advantages are obtained by the practice of the present invention:

(a) The advantage of cleaning the walls of a well bore just before and during the placing of the cement slurry, removing the mud cake from the wall of the well bore, thus permitting actual contact between the cement and the walls of the sections while placing the cement, thus insuring improved cement distribution and preventing fluid migration behind the casing.

(e) 'Ihe advantage of obtaining a perfect seal with cement in the annular space between the casing and the walls of the formation.

(j) The advantage of.' removing the mud sheath from the wall of the well bore in those sections where prevention of iiuid migration is necessary, which further prevents the cement slurry from channeling and provides a cleaned formation surface into which the excess mixing water from the cement slurry may fllter.

It will thus be seen that the invention here disclosed provides a simple and effective means for cleaning a well bore preparatory to setting a casing, and inexpensive means whereby the casing may be centered in a well bor'e preparatory vto a well cementing operation.

While I have shown only a typical preferred form of the means I have provided for cleaning a well wall of mud and for centering and cementing a casing in a well'bore, it will be understood that various changes may be -made in the invention by those skilled in the art without departing from the spirit of the invention as claimed, and it is to be further understood that this is a continuation in part of my co-pending application entitled Method and means of conditioning the walls of a well bore, Serial No. 291,027, filed in the United States Patent Oflice by me on August 19, 1939. I wish it understood that I do not limit myself to the particular details or application of the invention herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In combination, a tubular casing to be permanently installed in a well, a sleeve adapted to be secured on the casing to be lowered into a well thereon, a plurality of abrading fingers projecting from the sleeve in spaced relation to one another, the outer free ends of said fingers being adapted to engage the wall of a well bore into which the device is lowered, and means for yieldably supporting said fingers on the sleeve whereby the fingers may swing longitudinally of the sleeve.

2. In combination, a tubularA casing to be permanently installed in a well, a sleeve adapted to be secured on the casing to be lowered into a well thereon, a plurality of radially projecting abrading fingers arranged in spaced relation around the sleeve, the outer free ends of said fingers being adapted to engage the wall of a well bore into which the device is lowered, and means yieldably anchoring said fingers on the sleeve whereby the fingers may swing longitudinally of the sleeve, said fingers being disposed in sets of fingers lying in spaced transverse planes and with the fingers in each plane being uniformly spaced circumferentially and the iingersin the several planes being disposed out of axial alignment with each other.

3. A device of the character described, comprising a tubular cylindrical member adapted to be lowered into a well bore, semi-resilient elements carried thereby and spaced around the cylindrical member, said elements each comprising a semi-resilient radially disposed finger terminating in a free upwardly curved outer end and being formed integral at its opposite end with an arcuate semi-resilient element adapted to conform to the circumference of the cylindrical member, a plurality of longitudinally extending and circumferentially spaced ribs upon the outside of said cylindrical member having a, plurality of recessed seats spaced longitudinally of the ribs, the seats of the ribs lying in parallel transverse planes. the seats of a plurality of ribs in one plane receiving the semi-resilient arcuate portion, and means anchoring the free end of the semi-resilient arcuate portion to one of said ribs, whereby torque may be set up in the arcuate portion as the finger swings longitudinally.

4. A device of the character described, comprising a tubular cylindrical member adapted to be lowered into a well bore, semi-resilient elements carried thereby and spaced around the cylindrical member, said elements each comprising a semi-resilient radially disposed finger terminating in a free upwardly curved outer end and being formed integral at its opposite end with an arcuate semi-resilient element adapted to conform to .the circumference of the cylindrical member, a plurality of longitudinally extending and circumferentially spaced. ribs upon the outside of said cylindrical member having a, plurality of recessed seats spaced longitudinally of the ribs, the seats of the ribs lying in parallel transverse planes, the seats of a plurality of ribs in one plane receiving the semi-resilient arcuate portion, and means anchoring the free end of the semi-resilient arcuate portion to one of said ribs, whereby torque -may be set up in the arcuate portion as the finger swings longitudinally, said radial fingers in successive planes being circumferentially spaced with relation to each other whereby the fingers will be arranged in groups lying along a line of helix extending across the face of the cylindrical member and circumferentially thereof.

5. In well production equipment, a casing to be permanently set in the well, a sleeve on the casing, and a plurality of spring fingers spaced around the circumference of the sleeve and projecting outwardly from the sleeve to en'gage the wail of the well.

6. In combination, a well casing to be permanently set in a well, a sleeve secured on the casing. and a plurality of spring fingers secured to the sleeve and projecting substantially horizontally therefrom to engage the wall of the well.

7. In combination, a well casing to be permanently set in a well, a'sleeve secured on the casing, and a plurality of spring fingers secured to the sleeve and projecting substantially radially therefrom, the outer portions of the fingers being upturned and adapted to act on the wall of the well.

8. In combination, a well casing to be permanently set in a well, a sleeve secured on the casing, a plurality of spring members each including an elongate shank and a finger projecting from an end of the shank, and means confining the Shanks of said members against the periphery of the sleeve to extend circumferentially thereof so that the ngers project substantially radially from the sleeve to engage the wall of the well.

9. In combination, a well casing to be permanently set in a Well, a sleeve secured on the casing, a plurality of spring members each including an elongate shank and a finger projecting from an end of the shank, and means for holding said shanks against the exterior of the sleeve to extend circumferentially thereof so that said ngers project outwardly from the sleeve to contact the well wall, the contact of the fingers with the wall subjecting said Shanks to torque.

10. A device for use on a well casing comprising a sleeve to be secured on the casing, a plurality of flexible resilient members each comprising an arcuate shank adapted to conform to the sleeve when extending circumferentially thereof, and a finger adapted to project outwardly from the sleeve to engage the wall of the well, and means for holding said Shanks where they conform to the sleeve and allowing the application of torsion to the Shanks when said ngers engage the well wall.

11. A device for use on a well casing comprising a sleeve to be secured on the casing, a plurality of flexible resilient members each comprising an arcuate Shank adapted to conform to the sleeve when extending circumferentially thereof, and a finger on one end of the shank adapted to project outwardly from the sleeve, and means for holding said Shanks in general conformance to the sleeve so that the Shanks form torsion spring anchors for the fingers, said means including parts on the sleeve engaging each shank at circumferentially spaced points.

12. A device for use on a well casing comprising a sleeve to be secured on the casing, a plurality of flexible resilient members each comprising an arcuate shank adapted to conform to the sleeve when extending circumferentially thereof, and a finger on one end of the shank adapted to project outwardly from the sleeve, and means for holding Said Shanks in general conformance to the sleeve so that the Shanks form torsion spring anchors for the fingers, said means including longitudinally extending ribs on the sleeve engaging over the Shanks.

13. A device for use on a well casing comprising a sleeve to be coniined on the casing, a plurality of 'flexible resilient members each comprising an arcuate shank adapted to conform to the sleeve when extending circumferentially thereof. and a finger on one end of the shank adapted to project outwardly from the sleeve, and means for holding said Shanks in general conformance to the sleeve so that the Shanks form torsion spring anchors for the fingers, said means including longitudinally extending ribs on the Sleeve engaging over the Shanks, and end parts on the other ends of the Shanks cooperating with said ribs to anchor Said other ends of the Shanks.

14. A device for use on a well casing comprising a sleeve to be Secured on the casing, a plurality of flexible resilient members each comprising an arcuate Shank adapted to conform to the sleeve when extending circumferentially thereof, and a n nger on .pne end of the shank adapted to project outwagiily from the sleeve, and means for holdinglsai'd Shanks in general conformance to the Sleeve so that the Shanks form torsion Spring anchors for the fingers, Said means including circumferentially spaced longitudinally extending ribs on the sleeve extending over the Shanks and having recesses on their inner Sides receiving the Shanks, and 4bent over parts on the other ends of the Shanks engaging the ribs to prevent bodily turning of the Shanks and circumferential movement of the Shanks.

15. In combination, a perforate well casing intended to be permanently installed in the well, a sleeve secured on the casing, and a plurality of Spring members projecting substantially radially from the Sleeve for acting on the wall of the well.

KENNETH A. WRIGHT.

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