US2445100A

US2445100A - Anchoring means for whipstocks

Info

Publication number: US2445100A
Application number: US546994A
Authority: US
Inventors: Wright Stanley
Original assignee: Eastman Oil Well Survey Co
Current assignee: Eastman Oil Well Survey Co
Priority date: 1944-07-28
Filing date: 1944-07-28
Publication date: 1948-07-13
Anticipated expiration: 1965-07-13

Description

July 13, 1948. s. WRIGHT ANCHORING MEANS FOR WHIPSTOCKS Filed July 28, 1944 Patented July 13, 1948 I i 45 9 N s 7. Anaheim MEANS FOR wnlrs'roox's Stanley Wright; Long Beach; Calif assignor, by

direct and mesne' assignments, to Eastman'OiI 1 Well Survey'Company, Denver, (1010.; a corporation of Delaware .Application July 28, 194 1;; Serial 1 39?1 ,I v, a

' 11 Claims. (01. ass-1.6)

" This invention relates to new and useful improvements in anchoring means for whipstocks.

As is well known, 'whipstocks are used in well drilling operations ior guiding a drill bit intothe formation at an angle with respect to the main well bore,- their' use being particularly valuable in side-tracking or directional drilling" Because the whipstock 'must belowered andset improper position within the well bore, the outer diameter of said whipstock must necessarily be smaller than the inner diameter of the well bore, whereby there is a clearancefo'r .spacebetween the whipstocl; and wall of the bore after said whipstock is in its set position, When drilling offof the whipstock occurs, the resistance of the formation to the bits' entry causes thebit 'to' exert'a pressure against the lower portionof the whip-stock and this results in the whip'stock being forcedagainst the' wallof the bore'at a point opposite that at which the bit is engaging the formation; This lateral shifting of the whipstock is 'undesirahlebec'ause it obviously causes ajloss of the full deflecting value of thewhipstock. It is particularly disadvantageous when drilling off a cement plug orwhe f drilling in the harder sub-surface formations. j One object of the invention is to'prov'ide an improved means whichmay be attached-,to'the lower portion of a whipstock and which will effectively prevent lateral shifting or displacement of saidwhipstock whereby maximumdev flectionof the bit within the lim-its'of the whipstock is assured. I i v v v v p 4 An important object of the invention isto :provide improved means v f or preventing. lat'eral'shifting or displacement of a. whipsto ck, which 'fmeans may be constructed in the form of an attachment so as to -be readily appliedtotheusual whips tock :withoutf'any change in theIwhi-pstock construction; such arrangement making-it possible; to

utilizesaid means when the drilling conditions require it.

, jotherobject of the invention t fprbvide an improved means, of the characterhdes cribed, which includes a pivoted leg or support which of the whipstock, whereby said leg "engages the formation or plug, asthe case may be, prior,to engagement of the whipstock, with the result that s ubsequent continued lowering of saidwhipstocl; causesthe whipstock to fulcrum or swing toward that wall of the bore through whichdrilling is to occur; said leg or support also acting ,to lock the whipstock' against lateral displacement after the drilling operation is begun. f

.15v *'aftler""the drilling operation is completeflThe whips-took is'for'med with'an' elongate inclined guide surface I 6 which is arranged 'to 'gii'i'de the drill bit" 1'5 outwardly into the formation at an is attached'to and dependsbelow the, lower end the member'andwhipstock' 1 Still another object or the invention isto provid "anf' improved means of the character described; wherein the anchoring leg or menrber is pivotally connected to the Whip'sto'ck and-also wherein the construction is such that any thrust orload imposed on said-memberis carried solely by the member and no load or undue strain is imposed" upon the 5 pivotal connection between A-further' object of the invention to 'provide an imlp-rovfed device, of the character described; which comprises a minimumnumber of parts and which is so constructed that normally it does not P Qlect bey'ondt-he "outer diameter of th h o l w y said means *does not interfere with lowering ofthe -'whipstock within "thewell Qre'fl" The construction-designed to carry out the invention "will "be hereinafter described together with other f eatur'es'of the invention.

The invention will 7 be more readily understood from a reading of -the following'specification and by --reference to the accompanying drawing, wherein an exampleoftl're invention is'shown, and"wherein:' I Figure" 1'i's "a vi 'w of a whipstock having adevice, 'constructedin accordance with' the invention attached thereto, the whipstockbeing ima position just prior' to "setting thereof v "Figure 2 is a similar 'v'iew' with the'whlps'tock in its Setpositionfl Figure 3 is an enlarged, transverse sectional View of the device, may;

' Figure 4' isf 'a "cross-sectional view, taken on the In'" he drawings, the numeral 10 aesi'g ate 'a w'hipstock which is constructed in the usual manner. The whipstock includes an elongate what encircles'the drillj st m l3a'nd suitably connected thereto by'a shear pin-l4. "-Thelower 'end off'the'fdrill stem carries; a drillbit l5" which is disposed below the collar l2 and which is of a larger diameter than said Collar; whereby the bit may befutil'izedfto retrlevefthewhipstock angle to the main well 'bore A The whipstock generally semi-cylindrical in cross-section and the rear or trailing side I! extends substantially f p na to t longitudinal of the body. he lQ efe o ew p 'c s'pb n dia 'f nt me It W11 po n entail-n ates- 3 lar surfaces l9 and 20 which are cut in the lower portion of said whipstock. The above is the usual construction in whipstock and is described in detail merely for the purposes of a better understanding of the :present invention.

The whipstock is usually set upona cement plug B or is set in the formation at the lower end of the well bore A. Because said whipstock must be lowered through the well bore the size of the whipstock body ll must necessarily be smaller than the inner diameter ofsaidbore; thus when the whipstock is in its set position there is a clearance or space between the outer surface of,

said whipstock and the inner-wall of-the. well bore. In order to obtain maximum deflecting efliciency of the whipstock it is desirable that the lower end of the inclined guide surface it be maintained in engagement with the wall of the formation so that as the bit l moves downwardly,.the.- entry of the bit into the formation at an angle from the bore A- is assured, Since the usual whipstock has a space between its outer surface and the wall. of the well bore, it has been found that as the bit engages the formation,

theresistance of the formation to the entry of the'bit. will cause the bit "to exert apressure against the whipstock: whereby said whipstock is shifted later-ally Within the bore until the rear surface l1 abuts the wall of the-bore. Obviously such lateral shifting moves the inclined guide i face lfi away from the wall of the bore with the 'result'that some of the effectiveness or deflecting value of the whipstock is lost.

Inorder to assure the disposition of the lower end -oftthe inclined face of the whipstock in close proximity to the wall of the wellbore and also to prevent lateral shifting or displacement 'of said whipstock when drilling begins, an improved anchoring means is provided. Said means includes a channelshaped bracket 2| which is secured-to the inclined surface at the lower .end of the whipstock by suitablestud. bolts -.22. An elongate anchoring member or leg 23 is formed with a slot 24 in its upper portion and a pivot pin 25 which is mounted in. the bracket 2| extends through the-slot to pivotallymount the -member insaid bracket. Thelower end of the anchoringmember isnpointed or sharpened as shown at 26 and-this end is adapted to engage the plug 13 or formation on which. thewhipstock is set.

The member or leg 23 is normally held against a stop pin 21 which extends across the bracket by a flat spring 28. As is clearly shown. in Figure Bl the spring has oneend secured to the. bracket 5 with its other end overlying the edge of-the member-23. The stop pin 21 limits the inward move- 'ment of the member 23 while a stop web 29 which is preferably made integral with the bracket is secured in one end ,of the bracket and limits movement of the memberin anopposite orup- :ward direction. its normal position the member. is disposed ata slight angle (Figure 1) With respect to the longitudinal axis of thewhipstock body and in such position the lower pointed 1 end of themember is disposed in a plane well below' the pointed end l8 of said whipstock. With such arrangement the member 23 will first en-' In the operation of thede 'cethe parts arein the positionshown in Figure l and as the whipstock is lowered into position, the pointed end 26 of the member first engages the plug.'"'This the: timethatthe pointed end l8 of the whipstock has engaged the plug the-member 23 has assumed the position shown in Figure 2, in which position the inner or upper end of the member has engaged the stop web 29 whereby the thrust imposed upon-the member is taken by said member rather than by the pivot pin 25. As the pivotingaction occurs between the whipstock and the member23 the lower end of the whipstock is 1 the wall of the well bore.

shifted'so that the inclined guide surface [6 of said whipstock is moved into engagement with Of course, after the pointed end l8 of the whipstock has engaged the plug a two point contact of the whipstock with the formation is. had. Because of its inclination with respect to the longitudinal axis of the whipstock, the member 23 forms a brace which will prevent the whipstock ,being shifted laterallyduring subsequent drilling operations. Thus the arrangement provides not only for locating the lower end of the inclined surface H5 in close proximity to the wall of the well bore but also prevents lateral displacement of said whipstock after the same has been set.

The device is very simple in construction and includes a minimum number of. parts. One of its main features is the fact that it may be readily used with ordinary whipstocks without changing the construction of said whipstock. Thus, it may be used as an attachmentand may be secured to the whipstock if the subsurfaceconditions require its use. The member or leg 23, may be constructed of any suitable material and it has been found that hard wood issatisfactory although any desirable metal may be employed.

The foregoing description-of the invention is explanatory thereof and, various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is: V I

' 1. A whipstock including, an elongate body having an inclined guide surface and'also having a pointed lower end, and an anchoring member pivotally secured to the lower portion of the whipstock at a point spaced abovethe lower end,

said member having its lower end normally'projecting below the extremity of said whipstock whereby said member engages theformation or support on which the whipstock is set within the well bore prior to the engagement of the whipstock, the pivotal mounting of the member permitting swinging thereof upon continued downward movement of the whipstock to form an inclined brace for preventing lateral movement of the whipstock when drillin off of said whipstock occurs.

'2. A whipstockas set forth in claimfl, wherein the anchoring member is mountedon the. rear or trailing edge of the whipstock bodywvhich is substantially one hundred and eighty degrees opposite the inclined guide surface of said body.

3. A whipstock as set forth in claim 1, together with resilient means for normally urging the anchoring member toward a position inwardly of the body, whereby said member: will notinterfere with lowering ofthewhipstock within a well bore;

4. The combination with a whipstock having an elongate inclined guide surface, of an anchoring means including a support having means for attaching said support to the rear or trailing edge of the whipstock, and an anchoring member pivotally mounted in the support, said member being elongate and having its lower end projecting below the plane in which the lower end of the whipstock is disposed, said member being normally disposed at an angle with respect to the longitudinal axis of the whipstock, whereby when the member engages the formation or plug within the bore, the subsequent lowering of the whipstock causes said whipst-ock to be urged in a direction away from the lower end of the member and also whereby after setting of the whipstock said whipstock is prevented from lateral shifting within said bore.

5. The combination as set forth in claim 4, with spring means attached to the support and engaging the member to hold the member inwardly of the whipstock body whereby said member will not interfere with lowering of said whipstock within the well bore.

6. The combination with a deflecting tool having an inclined face of an attachment adapted to be connected to the lower end of said tool including, a bracket having means for connecting said bracket to the deflecting tool, an anchoring member having one end pivoted to the bracket, resilient means mounted on the bracket and engaging the member for urging the memberin a direction inwardly of the deflecting tool, and stop means mounted in the bracket and engaged by the member for limiting the inward movement of said member.

'7. The combination as set forth in claim 6, wherein the resilient means is a flat spring having one end secured to the bracket with its opposite end overlying and engaging one side of the anchoring member.

8. The combination with a whipstock having a lower pointed end of an anchoring means comprising, a bracket attached to the rear lower portion of the whipstock, an elongate anchoringmember having its lower end pointed and having its upper end pivoted to the bracket, the lower end of said member extending below the lower end of the whipstock, and resilient means carried by the bracket and engaging the member for urging the member inwardly toward the whipstock.

9. The combination with a whipstock having a lower pointed end of an anchoring means com.- prising, a bracket attached to the rear lower portion of the whipstock, an elongate anchoring member having its lower end pointed and having its upper end pivoted to the bracket, the lower end of said member extending below the lower end of the whipstock, resilient means carried by the bracket and engaging the member for urging the member inwardly toward the whipstock, and a stop element carried by the bracket and engaged by the member for limiting inward movement of said member, said stop being so located that the member is normally disposed at an angle with respect to the longitudinal axis of the whipstock.

10. A whipstock as set forth in claim 1, wherein the pivotal mounting between the anchoring member and whipstock body comprises a pin and slot connection, whereby after both the body and. member engage the formation a slight relative movement of these parts to permit their direct engagement is possible so that any forces against the body are transmitted directly to the anchoring member.

11. The combination set forth in claim 8, wherein the pivotal connection between the anchoring member and bracket comprises an elongate slot in the member and a transverse pin in the bracket, said slot and pin allowing relative movement of the bracket and whipstock with respect to the anchoring member, whereby after both the whipstock and member engage a formation or support within a well bore, relative movement of the parts is possible to allow the whipstock to directly engage the member and thereby transmit forces directly thereto rather than through the pivotal connection.

STANLEY WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,108,419 Trotter Feb. 15, 1938 2,170,284 Eastman Aug. 22, 1939 2,171,020 Achley Aug. 29, 1939 2,196,528 Hughes Apr. 9, 1940