Title:
Apparatus for forming a section of casing below casing already in position in a well hole
United States Patent 2447629


Abstract:
said Johnson assignor to Baash-Ross Tool Company, Los Angeles, Calif., a corporation of California Application May 23, 1944, Serial No. 536,908 11 Claims. (C. 166-4) 1 This invention relates to the art of lining wells, such as oil wells, with casings and is particularly directed to an apparatus...



Inventors:
Beissinger, Victor J.
Johnson, Glenn D.
Application Number:
US53690844A
Publication Date:
08/24/1948
Filing Date:
05/23/1944
Assignee:
RICHFIELD OIL CORP
BAASH ROSS TOOL COMPANY
Primary Class:
Other Classes:
166/277
International Classes:
E21B17/00; E21B29/10; E21B43/10
View Patent Images:



Description:

said Johnson assignor to Baash-Ross Tool Company, Los Angeles, Calif., a corporation of California Application May 23, 1944, Serial No. 536,908 11 Claims. (C. 166-4) 1 This invention relates to the art of lining wells, such as oil wells, with casings and is particularly directed to an apparatus by means of which a section of well casing may be formed at the end of a casing which has already been positioned in a well hole.

It is a customary procedure on completing an oil well to install in the well a string of casing known as a well casing in order to maintain the well bore and to prevent fluid from some of the formations from entering the well. This well casing is usually cemented into position at its lower end at least. After the well casing has been set in the well hole it may become desirable to extend the length of the casing below the bottom of the well casing as already set. Furthermore, it may become desirable to replace a section of the well casing already set. Thus, for example, where a section of the well casing is found to be defective or leaking, it may be desirable to remove this section of the casing. Also, it may be desirable to remove a portion of the well casing to perform additional operations back of the well casing, such as additional cementing operations. After the removal of the section of the casing, it may become necessary to install a new section of casing.

Previous to the present invention, whenever it has been found desirable to install another section of casing in a well hole after a well casing has been set in position, it has been necessary to install sections of casing of smaller exterior diameter than the interior diameter of teor diameter thanlready set in positionr diameterhis the well casing already set in osition, and this necessarily reduces the size of the well bore.

It is the general object of the present invention to provide an apparatus by which a new section of well casing of the same size as the casing previously set in the well may be formed at any desired position in the well hole.

Another object of the present invention is to provide an apparatus by which a new section of well casing formed in the well may be aligned with the previously set well casing. ther ob et of the resent invention is to 4 provide an apparatus by which a section of te provide an apparatus by which a section of the well casing already set in a well hole may be removed and a new section of well: casing of substantially the same size formed in the place thereof.

We have found that a new section of well casing of substantially the same size as the well casing already set in the well, may be formed in the well hole and aligned with previously: formed sections by the process and apparatus hereinafter described. In the process of the present invention the elements of a section of well casing are established in retracted position on a setting string. In this retracted position they may be lowered through the previously set well casing, although they are adapted to be expanded into a position to form a section of well casing of the full diameter of the previously set well casing. On lowering to the desired position, connection is made between these elements to the previous well casing in order to align the elements therewith. The setting string is then manipulated to move the elements from their retracted position into the position formed in the new casing, the setting string disconnected from the elements and withdrawn from the well hole. Finally the elements are cemented to the well hole. The new section of casing thus formed is anchored in place aligned with the old casing, and its formation does not reduce the size of the well hole.

The, apparatus of. the present invention includes the casing elements of the new section of casing to be installed, the setting string, and means for releasably connecting the elements to the setting string, which means allow for the positioniing or assembling of the elements in a retracted position. This releasable connecting means also includes means by which on relative longitudinal movement between the elements and the setting sring the elements may be moved from the retracted to a casing-forming position.

The elements are provided with spring arms or other suitable interconnecting means by which connection may be established between the elements and the previously' formed well casing, both in the retracted and expanded positions of the elements, whereby the new casing section so formed is wautomatically aligned with the previously set well casing.

The apparatus of the present invention, togeher w many further advantages of the inete with mny furter advantages of te nventlon, will be fully understood from a description of a preferred example of the invention, and for that purpose we have electedto illustrate an example of the invention as applied to the task of formiig a nev section of casini it place of of forming a new section of casing in place of a defective section of thewell casing previously set in the well. The apparatus by which new ections of a well casing can be formed at their position in the well hole will be apparent from the following description.

In the drawings: Figure 1 is a diagrammatic, vertical section. .55 through a well showing a well casing cemented in position and having a defective or leaky section which, is-toe be removed.

Figure 21 is a: view oft the same:well: after the,defective casing has been removed and the bore milled out preliminary to the forming of the new well casing.

Figure 3 is a view of the, same- well._showing, the apparatus of the present inventionin -:position adjacent the opening in the old well casing, thus produced, and preliminary, to, the-formation. of the new casing section.

Figure 4 is a view of the same well after :the step of moving the staves to'form-the new-casing; section.

Figure 5 is a view of the'same' well'after the cementing step.

Figure 6 is an enlarged elevation; mainly, in vertical section, of the apparatus positioned in the well bore and before the expanding operation.

Figure 7 is- a fragmentary: perspective view: ofone of: the: bottom centering, members, .Egurei 8:is; a view.:of-the apparatus:,in: overexpanded position, as taken on. the line. 8-8: of' Fig.. 16.

Figure 9 is a, section through the: apparatus, taken on the'line- 9;-9 of Fig. 6.

Figure 10' is a fragmentary. elevation, of the staves assembled .in position to- form, the new: casing' sectiom Figure, 11 is- a, section, on, the line 11-- l of Fige 1OJ Figure, 12 is: q fragmentaryl elevation of: one of the-inner staves.

Figure 13 is a fragmentary elevation of one 3 of the outer staves before the, addition of the guard members.

Figure 14- is- a fragmentary elevation, of' one of the inner' stave members showing the openings for the'installation. of the cam boxes: 4 Figure 15 is an enlarged fragmentraryvertical quarter'section of the-apparatus in the well' hole before the expanding- operationm Figure: 16: is- a- similar- view after the; overexpanding operation. 4 Figure 17- iS a similar view -after the- release of the mandrel.ftbm- the: formed casing-::section.Figure 18- shows a modified form of'theupper dogs_ to be-used;:where the new -casing Is to be. formed below the well casing. Referring, to the drawings,, the casing section. to, be produced is,'formed from a plurality of' casing, elements. As illustrated, these.casing elements, are. shown in. the. form of staves. The staves,arer divided, into, two. units, a set of inner 5: staves.. ,and asetof outer staves. 3. There are. equal, numbers of inner, and, outer staves,. In the. preferred, form of: the invention, four outer staves are employed. These staves mighthbe.produced through slitting .a section. of, well, casing 64 longitudinally.. The- staves. are. of. the. usual thickness of, well casing ordinarily employedlin oil: wells, or. may, be of, heavier materiall, and therefore have inherent rigidity, The staves are assembled"as indicated in Figure 9 with the inner 6! staves 2jin one. concentric series on the mandrel 4. The outer staves are arranged in a second concentric. series and' staggered- relative to the inner, staves 2.

In this position the staves are sufficiently com- 7( pacted so that,-they may -be-lowered' through thepreviously set well casing-in:the well T'-fbrm the well casing both the inner-staves 2' and the outer-staves,3·are moved radially from the-position.-Illustrated in Figure -.9;- the-inner :staves' :2 76 being interposed between the outer staves so that theybecome finally arranged in. one.circumferential series-.

To guide the stave members in these opera, tions, the stave members 2 and 3 are provided with cooperating guide means. For this purpose the inner staves are. provided with a plurality of pins'. 5 adjicent.their edges. The pins 5 extend radially from the, staves. The outer staves are 10. provided with slots 6 extending inwardly in a circumferential direction from their edges, and impositiorr for receiving the pins 5. The interSfitting 'engagement between the pins 5 and the slots61rlock the staves 2 and 3 from relative longi1s- tudirialmovement', while permitting both circumferential and radial movement of the staves.

They also permit, a relative radial movement between the staves so that the inner staves may be' positiofed as described, back of the outer staves. Preferably at each of the slots 0 the outer :staves are; provided with guards 7 which are: indicated as preferably welded to the staves.

The guards 7:extend beyond the edges of the staves and'are provided with elongated apertures 8 which through a portion of their length align with the slots 6 but which extend beyond the edges of the outer staves-3; These apertures receive.the'ends -of the pins 5, the' ends of the-apertures limiting: the circumferential separation of the staves. Tension means;are- provided for yieldingly urging:the stave: members: 3 toward the axis of the apparatus.: For this- purpose we preferably employ':ai:number, of elastic bands. 9 which are indi5a cated as' formed: of-helical spring wire. We have shown"-three of the: elastic bands 9 spaced apart andr'ate least- two. elastic bands should be used, one:adjacent eachend:of the:staves. We preferably"positionthe. guards in: sets spaced apart a 40'suitable distance; as indicated, for example, in Figure 10; in order to -retain the elastic bands in position, but'obviously; other means might be employed:for anchoring- the -guards in their correct longitudinal position with reference to the staves.

,5s For'expanding;thel staves radially, the mandrel. 4 :ls-indibatedi'as provided with two or more sets of circumferentially spaced hubs 10. Toothed cams'n1. :are pivoted to each of the hubs 10. The cams; :i as :indicated more particularly in Fig90 ures-l5. 16; andi 17, are of eccentric type and are intendedr:to .cooperate with cam. surfaces 12 on cam- boxes 13. Each: of the inner staves 2 is originally.: provided with at least two longitudinally spaced apertures 14; as illustrated in Figure 6i 14, and the cam- boxes 13 are welded in position insaid apertures_ 14. Counterclockwise rotation of' the :cams ::'I from the: position indicated in Figure:1-Sbyi longitudinal movement of the mandrel':4relative'to the stave members will expand , or move theKinner stave members 2 radially outward. This-positions the :inner staves 2 and also the outer staves 3 into the position illustrated in Ftgurese8 and 16. We- refer to this position as the over-expanded position since the staves have 5now'-been-.advanced radially to slightly beyond thei position in which they are finally to rest. In. this expansion of the stave members the apertures'.iin-.the'guards 7 control the relative circumferential movement of the staves 2 and. 3 and )-limit the separation of the staves.

A-'the' cam I I -passes the center position shown in Figure 16, it:disengages from the cam box 13 andddrops into -the' position shown in Figure 17, whereinthe staves are released from the mandrel S41 The- inner and outer: staves move radially until their edges contact under the influence of the tension bands 9 and assume their final position.

Each of the inner stave members 2 is provided at its upper end with a spring arm 15 having dogs 16 at their other ends, the dogs providing fingers 17 and shoulders 1'8. The spring arms 15 are compressed inwardly when the apparatus is passing through the well casing, but when the apparatus is positioned below the well casing, the arms expand and the fingers 17 contact the inner surface of the casing and come to center the apparatus with reference to the well casing. In the expanded position the shoulders 18 are adapted to engage the bottom of the well casing and stop the upward movement of the device when the mandrel is elevated. This provides a point of mechanical support for the device so that the upward movement of the mandrel may be translated into a force for pivoting the cams II. Preferably there are also provided spring arms 19 at the lower ends of the outer stave members 3.

These spring arms are provided with dogs 20 having fingers 21 for centering the apparatus with reference to the lower section of well casing, and have enlarged portions provided shoulders 22 for limiting the descent of the apparatus.

At their upper ends the dogs 20 have flanges 35 and the lower ends of the staves 3 overlap the flanges 35. Preferably there is installed in the apparatus a bearing surface between the mandrel and staves 2 and 3; and while various bearing surfaces might be provided we have indicated the mandrel 4 as provided with a collar 34 adapted to contact the upper ends of the flanges 35 to serve as this bearing surface. The staves 2 are indicated as of shorter length at their lower ends than the staves 3, in order to provide clearance for the movement of the dogs 20 on the spring arms 19.

For certain purposes, particularly where the apparatus is to be used in a process of forming a section of casing in the open hole below the well casing, additional centering devices may be employed, for which purpose the mandrel 4 is indicated as attached to a spring formed centering device 23.

With the apparatus described, the method of the present invention is as follows: Referring to Figure 1 of the drawings, we have indicated diagrammatically a typical well hole 24. Such a well hole is indicated as having the well-known water string 25 with a shoe 26 at its lower end. This water string is cemented in place, as indicated at 27. A well casing 28 is indicated as suspended at its upper end in the well hole by slips 29 mounted in a landing head 30. The well casing 28 extends to the bottom of the well and is there cemented into position, as indicated at 31. In the drawings the section marked X of the well casing 28 is indicated as of leaking and defective construction.

In the process of the present Invention, this defective section is first milled or cut away. For this purpose there may be employed any usual milling or cutting equipment, not shown. Following the removal of the defective portion of the well casing, the formation back of the well casing is enlarged, as indicated at 32 by means of any suitable expandable cutter or reaming tool. The enlargement of the well bore removes the-mud cake or other foreign impermeable material from the well bore and not only provides adequate space for the subsequent formation of a new casing section but also provides unrestricted access to the permeable formation back of the well casing and facilitates securing a good bond between the formation and the cement to be introduced as hereinafter described.

The staves 2 and 3 are then assembled in the position indicated in Figures 6 and 9 on the mandrel; that is the inner staves form one circle and the outer staves form a second circle, concentric therewith, with the outer staves staggered relative to the inner staves. In this assembling operation the pins of the inner staves are fitted into the slots for the outer staves, and the cams II on the mandrel are properly engaged with their cam surfaces. The tension bands are positioned as indicated, and the mandrel carrying these staves is attached to the end of a drill pipe 33.

The apparatus is then lowered into the well hole.

When the arms 19 pass below the ends of the casing 28 above the enlargement 32 of the well hole, the arms expand until the flanges 35 on the dogs 20 contact the lower end of the outer staves 3. In this position further lowering of the apparatus allows the fingers 21 to pass into the well casing 28 below the enlargement 32 where they are in position to center the device as hereinafter pointed out. When the shoulder 22 of the dogs 20 strike the upper end of the casing 28 below the enlargement 32 they arrest the further descent of the apparatus and signal the operator that the apparatus is at the proper depth in the well hole. When the spring arms 15 attached to the staves 2 pass below the casing 28 they expand immediately and cause their fingers 17 to contact the inner surface of the casing 28 and center the device with reference to the upper portion of the well casing 28.

The operator now elevates the drill pipe 33 and on contact between the shoulder 18 and the well casing 28 the upward movement of the staves is arrested and further upward movement of the drill pipe 33 causes the counter-clockwise rotation of the cams II, expanding the staves as heretofore described and interposes the inner staves 2 between the alternate outer staves 3, Sforming the same into a circumferential series to conform to a well casing section. Further movement of the drill pipe 33 releases completely the mandrel from the thus-formed well casing section and the drill pipe and mandrel are then withdrawn from the well hole. As the outer staves 3 expand, the fingers 21 on the dogs 20 move outwardly into position to contact the well casing 28 below the enlargement 32 of the well hole and these fingers then center and align the formed well casing section with the lower portion of the well casing 28.

The produced casing section is then cemented in position in any ordinary or desired manner.

C, For example, a packer may be lowered down and positioned at a medial point along the newly formed well casing section. Cement is then pumped down the well casing and caused to flow under the bottom of the staves into the enlarge05 ment 32 of the well hole and up around the two ends of the casing 28 and back of the newly formed casing, locking the old casing 28 with the new casing section. Subsequently the packer is removed and after setting of the cement the bore of the new pipe section is drilled out to conform with the bore of the portions of the casing 28 above and below the new section.

In drilling out the bore of the newly formed casing, the dogs 16 and 20 are drilled out. To facilitate the drilling out of these dogs they are preferably foirmed of- a friable o reddily'- drillable mraterials;,such as i ast iron. The pins 5, -'guards 7, elastic bands 9 'and spring arms -' 5'-ahd'9 remain imbedded in the cement b ackebf :the finely formed casing secti~on and anchor arid 'reinforce the section.

Ndw 'referingĂ˝ to-Figure 18 'of :thedraWngs, we have shown a miodification :of ::-the :apparaitus whfh-ichay be iused 'where the -new 'well -asing is to ebe 'formed' below -the already, set :well- casing.

In Figure 18 the -well basing 28 is iidicated'as terminat~iing as usiually :i--a float-sho 36. The dbgs - 1 attached to the -spring arms 15 iin this modification hiave'fingers- 17 which are provided with heads or hooks 37 which are adapted to catch on the ffloat-shoe'36 and isuspend the newly formed section from said float-shoe until 'the i.neWly formed section has been cemented in :place.

-With the apparatus of the'present invention it is 'therefore possible to install a section of well 'casing boffull size in a weltl hole :tei` the well casing has been set in position'in the well hole.

By nmeans of the present invention it is therefore possible to preserve the diameter of the well; the diameter of which has previously been'always reduced by these operations.

While the specific examples of hthe 6apparattus herein described are well adapted to carry but the objects of the invention, it 'Willbe' obvious that variouls 'modifications may be :made in the details of'the apparatus' employed, without rdeparting from the principles of the invention, and this invention includes such modifications :and advantages as come within the scope of the' appended claims.

We claim: 1. An apparatus: for forming sections 'of casing in a well:hole, comprising a mandrel, a set of inner staves and a set of outer staves supported by said mandrel, expanding means interconnecting said mandrel and staves for moving the staves radially upon relative axial movement' between said mandrel and staves, and guiding members interconnecting said staves operative for guiding the staves into circumferential alignment on radial expansion of the staves.

2. An apparatus for forming well casing sections, which comprises an inner set -and a concentric outer set of casing staves, a mandrel supporting said staves, interconnecting expanding members between the mandrel and staves for radial advancement of the staves on relative axial movement between the staves and mandrel, and tension means for yieldingly urging the -staves radially.

3. An apparatus for forming a casing section in a well hole below a previously set casing, comprising a mandrel,. a plurality of casing staves mounted on the mandrel, radially advancing members between said staves and mandrel for radially advancing the staves on relative axial movement between the mandrel and staves, said staves having interconnecting guide members for circumferentially aligning the staves when radially advanced, and centering arms connected to the staves adapted for making centering contact with the well casing below which the 'casing set-ion is to be formed.

4. In an apparatus for forming a section of-basing, a plurality of inner casing staves and a complementary number:of outer casing staves, a pin and slot guiding connection between the inner and outer staves,'and spring arms' connected to the staves having centering fingers.

'5. In an apparatus for forming a section-of . ell casing, a plurality of inner staVes arid a. complementary number of outer staves, a pin and slot guide-connecting means between the inner: and outer staves, a set of spring arms having eentering fingers connected to the inner stavess at their upper ends, and a set of spring arms having centering fingers connected to the outer staves at their lower ends.

6. In an apparatus for forming well casing sections, a mandrel, a plurality of pivotally movable toothed cams connected to said mandrel, a plurality of stave membe-s supported by said mandrel and having toothed cam surfaces for choperation iith said cams, the cams being positioned for radially advancing the staves on pivotal movement of the cams, said cams being adapted to release the staves on completion of the pivotal movement of said cams.

7. In an apparatus for forming well casing sections, a mandrel, a plurality of pivotally movable toothed cams connected to said mandrel, a plurality of stave members supported by said mandrel and having toothed cam surfaces for cooperation with said cams, the cams being :positioned for radially advancing the staves on pivotal movement of the cams, said cams being adapted to release the staves. on completion of the pivotal movement of said cams,: and interconnecting gu'de means between the staves for circumferentially aligning the staves upon 'their radial movement.

8. In an apparatus for forming a sectidn bf well casing in a well hole, in which a well'casing has been previously set, a plurality of staves, means for mounting said staves for radial movement from a nested position to a circumferentially aligned position wherein the staves define a casing section, spring arms connected to the staves at their lower ends, and having stop blocks for arresting the movement of the staves at the position of the well hole where the casing is to be produced.

9. In an apparatus for forming a section of well casing, a circular series of stave members, a concentric outer series of stave members, the staves of the outer series being staggered to the staves of the inner series, means for radially ad50 vancing the staves, means, interconnecting' the staves for guiding the same into circumferential alignment upon expansion, and tension bands yieldably urging the stave members radially inward.

10. An apparatus for forming sections of casing in a well hole, comprising casing elements, means for releasably mounting said elements in retracted position on a setting string, means for interconnecting said elements with the previously set casing while said elements are in retracted position, and means carried by the setting string for expansion of the elements on relative movement between the said elements and'setting string.

11. An apparatus for forming a casing section in a well hole below a previously set well casing, comprising casing elements,. means for releasably connecting said casing elements to a setting string, said releasable connecting means allowing for movement of the casing elements from a retracted position to an. expanded position. on relative movement between said elements and said setting string, and interconnecting .means on said elements for establishing connection and alignment between said elements and the, previously set well casing on lowering of the elements and setting string adjacent thereto, said means being adapted for establishing connection between said elements and said previously set well casing while said elements are connected to said setting string.

VICTOR J. BEISSINGER.

GLENN D. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent: UNITED STATES PATENTS Name Date Simmons --------- Oct. 4, 1932 Price ------------ Nov. 20, 1934 Yowell --------- Sept. 15, 1936