CA1210688A

CA1210688A - Bore hole plug

Info

Publication number: CA1210688A
Application number: CA000462827A
Authority: CA
Inventors: Jim Jackson
Original assignee: J J Seismic Flowing Hole Control (C I) Inc
Current assignee: J J Seismic Flowing Hole Control (C I) Inc
Priority date: 1984-09-10
Filing date: 1984-09-10
Publication date: 1986-09-02
Also published as: US4633946A

Abstract

THE ABSTRACT OF THE DISCLOSURE
There is provided a new and useful bore hole plug comprising a central support member, an expandable sleeve secured about the central support, a first reactant chemical within the sleeve which is capable of reacting with a second reactant chemical or a catalyst to form a closed cell foam, and means by which the second reactant can be introduced to the sleeve.

Description

This a~plication relates to bore hole plugs.

In carrying out a seismic exploration, a standard procedure i8 ~0 drill holes into the geologic formations o~
interest and to plant explosive charges in ths bore holes. The charges are then detonated and appropriate measurements ~ecorded to enable evaluation of ~he formation.
There are a number of problems a6sociated with this seismic drilling~ One of these occurs during the actual blast. Unless the hole is properly plugged p~ior to detonation, a large proportion of ~.he energy of tha blast escape6 upwardly ~hrough the hole and is thus not properly directed through the formation of interest.
A second problem which frequently arises is that the boring and hla6t releases from the formation water under pLesSUre which then escapes through the hole. A bore hole plug is necessary to stop the water flow.
There is ~herefore a continuing need for a bore hole plug which is 6imple and inexpensive in construction yet sufficiently duLable to remain in place for extended period~
and to withstand the force of the blast and of the water. To date, a variety of plugs have been proposed and used, but these do no~ satisfactorily meet all o the criteria set out above.
The bore hole plug of the present invention is ~,,1 ~,., ~Z~~8~
intended to alleviate the problems discussed.

PRIOR ART

There are a number of United States and Canadian ~aten~s which fall into the general area of interest but which are defi.cient in one or other aspects. Among United States patents of interest is United States Patent 2 7 609,880, issued Seetember 9, 1952 to one Dyer. In this case the container i6 partitioned to contairl two reactants such as water and cement.
The object, however, is to plug a fracture Ol the like at the side of the bore hole, and ~he device would not be suitable nor is it intended to seal the bore hole itself. In particular, the container is destroyed or removed from the hole in bringing the two reactants toge~her, and it is ~herefore no~ apparent that any seal at all would be formed in the bore hole itself.
United States Patent 2,966,946, issued January 3, 1961, to McCulloch et al., provides a rather comple~ device one a6pect of which is an air inflatable sleeve. Compres6ed air is provided from a cylindeL that is held within the plug.
Inherent in this device are the disadvantages of all of the air inflated types: namely, that there is a tsndency over the long term for leakage and deflation and, as well, ~here is a real danger of ruptuLe. Clearly, rupture of the sleeve is disastrous in an air infla~ed device.
United States Patent 3,130,787, issued A~ril 28, 1960 ~2~
-~o Mason, is a relatively simple inflatable bag type plug. In addition to the disadvantages generally inheren~ in air in1atables, this device has in addition the disadvantage that it is ;nflated via compres60r and piping from the sur~ace and therefore adds this complexity and expense.
Canadian Paten~ 703,786, is~ued February 16, 1965, to 5mith provides another a;r expandable plug. This device has a number of disadvantage6 similar to thos~ o~ the Mason patent.
Canadian Patents 840,~18, issued April 28, 1970 and 10 889,69~ issued January 4, 1972, both to Bassani, provide yet another air inflatable where the air for inflation is provided from the surface.
Canadian Patents 921,399, issued FebruaLy 20, 1973 and 951,241, issued July 16, 1974 both to Schlu~burger Canada Limi~ed, are typical of a large group of prior art patents which pertain to complex plug arrangements, designed wi~h a flow through bLidge which can eventually be blocked to provide a complete plug. In general the complexi~y of these devices adds greatly to the expense and renders them undesirable for use in seismic drilling.
Finally, Canadian Pa~ent 1,117,865, issued Febru~ry 9, 1982, ~o Ditto, provides another air inflated plug wherein the gas cylinder provid;ng the compressed air i6 located in the plug. The air release is by way of an electEically operated valve which is in ~urn connected to the surface and to a source of electric current by a pair of lead wires. Again, this device has the disadvantage of the air inflatables with surface connec~ion.
In cont~st, the plug of the present invention utilizes an inflatable sleeve and reactants which are brought into contact to form an expanding settable foa~l which set,s in the bore hole to ~orm an effective and un;form s~al. The effectiveness of the seal is thus not afEected by leakage nor by rupture of ~he sleeve.

~UMM~RY 0 THE INV~NTION

The invention utilizes an inflatable bag or sleeve to ef~ect a uniform and permanent plug in a bore hole. At least one source of reactant is located within the sleeve and means is provided for effec~.;ng contact between the first reactant and a second reactant or a ca~alyst, the source of which may or may no~ be located within the sleeve. The reac~ants are chosen such ~hat, upon contact, ~hey react to expand into a se~table foam. The foam sets in the hole to form an extremely hard and durable plug.
Accordingly, the invention provid0s a bore hole plug comprising a central su~port member, an expandable sleeve secured about the central su2port, a first reactant chemical within said sleeve which is capabla of reacting with a second reactant chemical to ~orm a closed cell foam: and means by which the second reactant can be introduced to the 61eeve.

z~
In a further embodiment the invention provides a bore hole plug comprising a central suppQrt member, an expandable sleeve secured about the central support, at least two discrete sources of reactan~ chemicals within the sleeve, each of which pLovide~ a chemical, the chemicals being such that they react upon contact with each other to expand into a settable foam, and means as~ocia~ed with the central support member for effecting contact between the reactants.
In a further embodiment ~he invention provides a bore hole ~lug comp~ising a central hollow cylindrical support member having a pair oE slots through the side wall thereof and having to~ and bottom end closures, an expandable sleeve member secured about the support member and encompassing the slots, a pair of fLacturable containers within the sleeve and disposed adjacest the slots, each containing a reactant chemical, ~.he chemicals shosen such that they react upon contact with each other ~o ex~and into a settable foam, a pair of arms pivotally mounted in the central member and adapted to rota~e from a first eosition within the member to a second position extending through res~ective ones of the slots, and a control rod extending through and slidable Lelative to the top closure for effecting rotation of the ar~s, whereby rotation of the arms from the first to the second position causes the arms to fracture the containers ~o thereby effect contact between the reactants.

BRI F DESCRIPTIO~_OF THE DR~WINGS

In dLawing~ which illustrate embodim~?nt~ of the inven~ion, Figu~e 1 is a side elevation partl~ in section of a plug acco~ding to the inven~ion;
Figure 2 i6 a side elevation partly in section illustrating a further embodiment of the invention:
Figure 3 is a view similar to Piyure 2 where the plug has been inflated;
10Figu~e 4 is a side elevation partly in section illustrating a further embodiment of the invention.
While the invention will be described in conjunction with ~he illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifica~ions and equivalents as may be included within the spirit. and scope of the invention as defined by the appended claim6.

DETAIL~D ~S~RIPTION O~ THE INV~NTION

20In the following description, similar features in the drawings have been given similar referance numerals.
With reference to Figure 1, plug lO comprises ~he cent]:al support member 12 about which is secured the inflatable sleeve 14. Sleeve 14 is secured by mean~ of clamp 16 ~o the lower end ca~ or collar 18 and by means of clamp 20 to ~he u~per end collar 22. End cap 13 and collar 22 are securQd to the central support memher 12. End cap 18 is pre~erably cone-shaeed at the lower end to facilitate erllcy and travel of the p].ug in the bore hole.
The member 12 is preferably a length o~ PVC plastic pipe, and the end cap l~ and the collar 22 are preferably of ABS plastic. Typically the pluy will have an overall length in ~he area of eighteen inches. The diameter of uninflated sleeve 14 and of end cap 18 and collar 22 are such as to provide sufficient clearance for insertion ~f ~.he plug into a bore hole.
The sleeve 14 i5 an expandable elastic material such as rubber.
The member 12 is provided w;th at least one opening for communication betwee~ the interior 24 of the member 12 and the inte!ior 26 of the sleeve 14. In Figure 1 fou~ such openings comprising elongated slots 28 are illustrated.
20Also in Figure 1 the tubular membar 12 is provided with a closure 30 comprising, as illustrated, a threadad ~lug.
In the case illustrated the plug i~ actually inserted into a tube 31 leading to tube 12. However~ plug 30 could as well bP
attached directly to collaL 22. ~ny similar removeable closure 30 to seal the member 12 would be suitable and, in particular, once in place in a use situation, it is no~ contemplated that the clo~ure 30 would normally be removed. Therefsre, it i8 generally only nece6~ary that the clo~ure 30 ~eal and hold adequately again6t the expanding foam, BO a qlliCk 8etting cement, a clamp, or the like may be found suitable in ~ome situation6.
The plug lO include6, in the most gene~al configuration, illustrated in Figure 1, a fir6t chemical reactant 32 located in the 61eeve 14. Thi6 reactant i~ one which, upon contact with a second reactant o~ a cataly6t 33, reacts and expand6 to form a closed cell foam.
In use the clo~ure 30 i6 removed, the catalys~ 33 added to the tubular member 12, and the clo6ure 30 replaced.
The whole container i8 then agitated, as by hand shaking, ~o promote movement of the first reactant and the ca~alyst between the ~ubular member 12 and the sleeve 14 to ~romote good contac~. T~e plug i6 then simply dropped into the bore hole where the reaction goes to completion, expanding the sleeve 14 tightly against the bore hole wall6 to effect the ~eal.
Clearly, in sei6mic bla~ting, the explosive charge will have been set in the bore hole prio~ to in~ertion of the plug.
In the flow control ca~e, it may be nece~sary to hold the plug at the proper depth in the hole until the foam has ~et. This can be done by utilizing rods extending from the surface down into the borehole to threadedly engage the end collar 22 in place of ~lug 30. The rod6 can then be removed when the foam has set.
In a modification of this embodiment, the catalyst or ~econd reaceant 33 may be loca~ed in a fracturable containQr in the tube 12. Prior to use the p:lug 30 i5 removed and a su;table prod inserl~d to ~ear or break the fracturable container. The prod is then removed, plug 30 rein~erted, and the ~lug lO shaken. The plug lO is then inserted into the hole prior to the foam setting. ~s with the firs~ embodiment discussed above, in the case of a flowing hole, the closure 30 can be ~eplaced by a connection to the surface to position the plug lO un~il setting is complete~
~ second embodiment of the invention is illu~trated in Figure Z. In ~hat embodiment the plug as an operating unit is com~letely self-contained in tha~ both the firs~. and second reactants are located within the sleeve 1~.
Pr~ferably, the reactants are located in a pair of containers 34 and 36 in ~roximity to central memb~r 12. The chemicals as above are chosen to react upon contact to expand into a set~able foam. The foam iz chosen to be of a type that will set into a very hard material.
In order to effect contact between the chemicals in containers 34 and 36, the mechanism 37 is provided for breaking or puncturing the containers. Clearly, the containers 3~ and 36 are compri~ed of a material which can readily be punctured.
In the preferred case the means for effecting rup~ure of the containers comprises a plunger arm 38 with which is ~hreadedly 8~
engaged a set of arms 40 on a pivotting mechanism 42. The arms are preEe~ably spring biased toward the closed position illustrated in Figure Z.
Prior to use of the plug, the wing6 30 are maintained in the closed posi~ion illustrated in Figure 1 by virturQ of abuttment against the inner walls o~ the member 12 or by the spriny bias. To effect rupture of the container6 34 and 36 and subsequent contact of the chemicals contained in the containers, the plunger 38 i8 moved downwardly in the member lZ
to a position where the wings 40 can extend ou~wardly through slots 28 provided Eor the purposa in the member 12. A camming mechanism is provided in the connection 42 to extend the arms 40 when plunger ~8 is depressed. The containers 34 and 36 are preferably positioned adjacent the 510t6, S0 that when the 15 wings 40 move into the open ~05i~i on, ~he containers 34 and 36 will be ruptured and the chemicals wi.ll. be released ~o contact each other and begin the foaming reaction.
The plunger 38 is removed from the mechanism 42 (by disengaging the threads) and a~ end closure such as plug 30 of Figure 1 is inserted.
The chemicals can be chosen to react at a sufEiciently 810w rate that the plunger can be activeated at the surface to begin the foaming reaction and the plug subsequently dropped into the bore hole. In this situation, it is unnecessary that theLe be any connection at all as bet~een the plug and the surface of the earth~ As with the earlier cases, however, a surface connection may be utilized in cases where the plu~ must be positioned and held until the foam is set in a flowing hole.
The chemicals are chosen to produc~ a foam which will e~pand sufficiently to force the sleeve 14 to expand again~t ~he walls of the bo~e hole to form a tight seal. The ~oam will set to a very hard and dur~ble mass. Such foams are readily available from manufacturers.
In an alternative embodiment, the wings 40 are spring biaæed to the o~en ~osition of Figure 3, so that they assume the open positiQn when the plunger 38 i8 depres~ed to the point where wings 40 reach the upper ends of slots 28. Continued depression of the plunger with the arms 40 extended, further aids in rupture of containers 34 and 36 and in subsequent mixing of the two reactantsO
The embodiment illustrat0d in Figure 4 enhances the effectiveness of the invention. While it is applicable ~o either of the Figure 1 or 2 embodiments, it is particularly useful with the Figure 1 situation.
Her~ the plunger 38 is fitted with a mixing device 44 which may take a variety of forms but is preferably a ~erforated or webbed ring. The ring 44 is joined to the plunger 38 by the rods 46 and 48 which extend through the slots 28 in the tubular member 12 to the threaded collar 49.
In operation, and based on the Figure 1 embodimen~, the s~cond reac~ant or catalyst would be added to the tubular member 12 and the ~lunger 38 would be moved up and down in the member ~2 thereby enhancing mixing between the reactants. This may be further enhanced by agitation of the plug as a whole.
The plungeL is then preferably removed by unscrewing from threaAed collar 49.
Thus i~ i6 apparent that there has been provided in accordance with the invention a bore hole plug tha~ fully satisfie~ the objects, aims and advantages 6et forth above.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of ~he foregoing description.
~ccordingly, i~ is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.

~2~

SUPPLE~E~TARY DISCLOSUR~

In a pre~e~red embodiment the foam may be ~olyure~hane or urea based, and the reactan~s or reactant and catalys~ to produce the foam in situ are available commercially~ For e~ample, a suitable polyurethane based polymer comprises a~
reactants 32 and 33 a polyol and an isocyanate. One such reactant pair is produced by Denys N.V. of Belgium under product designation JJ FO~M 360W and di~tributed in Canada by Denca Construc~ion Specialties Inc. of Edmonton.
~ 6uita~1e urea based polymer compri~es as reactant 32 and catalyst 33 respectively a polyurea polyalkylene oxide and an amine ca~alyst. One such polymer i~ available Erom the above ~u~plier under t~e product designa~ion DECI 16 (Deci is registe~ed trade mark); and one such catalyst i5 available under the produc~ designation D2CICAT 16.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
l. A bore hole plug comprising:
a central support member;
an expandable sleeve secured about said central support;
a first reactant chemical within said sleeve which is capable of reacting with a second reactant chemical or a catalyst to form a closed cell foam; and means by which said second reactant can be introduced to said sleeve.
2. The plug of claim 1 wherein the said central support member is an elongated tubular member having top and bottom ends and closed at the bottom end thereof.
3. The plug of claim 2 wherein said tubular member is fitted with top and bottom collars to which respective top and bottom members of said sleeve are secured.
4. The plug of claim 2 wherein openings are provided in said tubular member for communication between the interior of said tubular member and the interior of said sleeve.
5. The plug of claim 4 including a removeable closure member in the top end of said tubular member.
6. The plug of claim 5 wherein said closure member is threadedly attached to said tubular member.
7. The plug of claim 5 wherein said means by which said second reactant can be introduced comprises said tubular member and said openings.
8. A bore hole plug comprising:
a tubular central support member having a top and bottom end and closed at the bottom end;
a collar secured around each end of said member;
an expandable sleeve having top and bottom ends secured respectively to said collars;
at least one opening for communication between the interior of said tubular member and the sleeve;
a removeable closure threadedly secured in the top of said tubular member; and a first reactant chemical within said sleeve which is capable of reacting with a second reactant chemical or a catalyst to form a closed cell foam.
9. The plug of claim 8 in which said second reactant chemical or catalyst is contained in a ruptureable container located in said central support member.
10. The plug of claim 8 or 9 wherein said central support member contains a series of elongated slots for communication between the interior of said support member and the interior of said sleeve.
11. A bore hole plug comprising:
a central support member;
an expandable sleeve secured about said central support;
at least two discrete sources of reactant chemicals within said sleeve, said chemicals being such that they react upon contact with each other to expand into a settable foam; and means associated with said central support member for effecting contact between said reactants.
12. The plug of claim 11 wherein the said support is an elongated member sealed at the ends thereof.
13. The plug of claim 12 wherein the said central member is a hollow cylinder including top and bottom closures.
14. The plug of claim 13 wherein the said central member includes end collars at each end thereof and wherein said sleeve is clamped in place around said collars.
15. The plug of claim 11 wherein said sources of reactant chemicals comprise a pair of breakable or punctureable containers.
16. The plug of claim 13 wherein said sources of reactant chemicals comprise at least one breakable or punctureable container.
17. The plug of claim 16 wherein the said sources comprise a pair of said containers.
18. The plug of claim 17 wherein the containers are located adjacent said central member.
19. The plug of claim 18 wherein the containers are located on opposite sides of said central member.
20. The plug of claim 16 wherein said top closure is removeable; wherein the said central member includes at least one slot through the side wall thereof; and wherein said means associated comprises at least one arm pivotally mounted in said central member, and adapted to rotate from a first position within said central member to a second position extended through said slot, and a control means extending out of the top of said central member for effecting rotation of at least one arm; whereby rotation of said at least one arm from said first of said second postion causes said arm to fracture said at least one container to thereby effect contact between said reactants.
21. The plug of claim 16 wherein said top closure is removeable; wherein the said central member includes at least one slot through the side wall thereof; and wherein said means associated comprises a plunger extending out of the top of said central member and moveable longitudinally relative thereto from a first upper to a second lower position, and at least one arm pivotally attached to said plunger and moveable and spring biased from a closed toward an open position, and wherein the said arm is so located relative to said at least one slot that when the said plunger is in said upper position, said at least one arm abuts against the inner surface of said central support member and when said plunger is moved to said lower position, said arm assumes said open position by rotation through said slot.
22. The plug of claim 19 wherein said central member includes a slot therein adjacent each said container; and wherein said means associated comprises a pair of arms pivotally mounted in said central member and adapted to rotate from a first position within said central member to a second position extending through respective ones of said slots, and a control means extending out of the top of said central member for effecting rotation of said arms; whereby rotation of said arms from said first to said second position causes said arms to fracture said containers to thereby effect contact between said reactants.
23. The plug of claims 20 or 21 wherein said control means comprises a rod slidable relative to said central member.
24. A bore hole plug comprising:
a central hollow cylindrical support member having a pair of slots through the side wall thereof and having a bottom end closure;
a top end closure adapted to be secured in the top end of said central member;
an expandable sleeve member secured about said support member and encompassing said slots;
a pair of fracturable containers within said sleeve and disposed adjacent said slots, each containing a reactant chemical or a catalyst, the chemicals chosen such that they react upon contact with each other to expand into a settable foam;
a pair of arms pivotally mounted in said central member and adapted to rotate from a first position within said member to a second position extending through respective ones of said slots; and a control rod extending through and slidable relative to the top of said central member for effecting rotation of said arms;
whereby rotation of said arms from said first to said second position causes said arms to fracture said containers to thereby effect contact between said reactants.
25. The plug of claim 19 wherein said openings include at least two longitudinally extending slots and wherein the plug includes a rod extending longitudinally through and slidable relative to the top end of said tubular member into the interior thereof, an annular ring between said tubular member and said sleeve, and connecting members extending through said slots to secure said ring to said rod, whereby longitudinal movement of said rod will cause said ring to move correspondingly in the space between said tubular member and said sleeve to rupture said containers and mix said reactant chemicals.
26. The plug of claim 25 wherein the said connecting members are joined to a collar and wherein the said rod threadedly engages the said collar.

CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE
27. The plug of claims 1, 2 or 4 wherein the said foam is polyurethane or urea based.
28. The plug of claims 1, 2 or 4 wherein the first and second reactants are respectively a polyol and an isocyanate.
29. The plug of claims 1, 2 or 4 wherein the first reactant is a polyurea polyalkylene oxide and the catalyst is an amine.
30. The plug of claims 8, 9 or 10 wherein the said foam is polyurethane or urea based.
31. The plug of claims 8, 9 or 10 wherein the first and second reactants are respectively a polyol and an isocyanate.
32. The plug of claims 8, 9 or 10 wherein the first reactant is a polyurea polyalkylene oxide and the catalyst is an amine.
33. The plug of claims 11 or 24 wherein the said foam is polyurethane or urea based.
34. The plug of claims 11 or 24 wherein the first and second reactants are respectively a polyol and an isocyanate.
35. The plug of claim 11 or 24 wherein the first reactant is a polyurea polyalkylene oxide and the catalyst is an amine.