OA12299A - System for creating a conduit in a borehole formedin an earth formation. - Google Patents

Abstract

A system is provided for creating at least one conduit in a borehole formed in an earth formation. The system comprises a device which includes movement means for moving the device in longitudinal direction through the borehole, and injection means for injecting a hardenable substance into the borehole so as to form, for each said conduit, a layer of hardened substance in the borehole behind the device, said layer defining the conduit. The system further comprises control means for controlling the rate of injection of said substance by the injection means so as to correspond with the rate of movement of the device through the borehole by the movement means.

Description

01229g

The présent invention relates to a System forcreating at least one conduit in a borehole formed in anearth formation. Conventional Systems for creating aconduit in a borehole formed in an earth formationinvolve, for example, the provision of a liner to theborehole wall during drilling of the borehole. SuchSystems operate on the basis of a rotating drill string,or a stationary drill string provided with a downholemotor for rotating a drill bit. Generally, a relativelylarge and expensive drilling rig at surface is requiredto suspend the drill string in the borehole.

International patent application WO 98/59146discloses a drilling system which includes a drillingdevice obviating the need for a large drilling rig, whichdevice is powered by an electric cable extending throughthe borehole to surface. Drill cuttings resulting fromthe drilling process are deposited into the boreholebehind the drilling device. One of the drawbacks of theknown drilling System is that there is no possibility ofdirecting a stream of fluid to the drilling device, forexample in order to cool the drilling device, to powerthe drilling device or to transport excess drill cuttingsto surface.

It is therefore an object of the invention to providean improved drilling system, which overcomes thedrawbacks of the known drilling system.

In accordance with the invention there is provided asystem for creating at least one conduit in a boreholeformed in an earth formation, the system comprising adevice which includes: 01229g movement means for moving the device in longitudinaldirection through the borehole; and injection means for injecting a hardenable substanceinto the borehole so as to form, for each said conduit, alayer of hardened substance in the borehole behind thedevice, said layer defining the conduit; the Systemfurther comprising control means for controlling the rate of injectionof said substance by the injection means so as tocorrespond with the rate of movement of the devicethrough the borehole by the movement means.

It is thereby achieved that each conduit is createdand extended continuously in the borehole during movementof the device through the borehole, without the requirement of a large drilling rig. Each conduit thuscreated with the System allows a stream of fluid to flowto, or from, the device in the borehole. Furthermore,each conduit is available for hydrocarbon fluidproduction once the device has arrived in a hydrocarbonfluid containing formation.

Suitably the injection means is arranged to injectthe hardenable substance into the borehole so as to forma cladding of the borehole wall. The cladding can, forexample, be provided at selected sections of the boreholeto prevent inflow of water from the earth formation intothe borehole or to seal (natural) fractures présent inthe formation.

Preferably the System further comprises a remotecontrol unit for controlling the device, the remotecontrol unit being in fluid communication with the devicevia each said conduit.

In case the hardenable substance is formed from amixture including a first and a second compound, theinjection means preferably includes a first containercontaining the first compound, a second container 3 °>229g containing the second compound and a mixing chamber formixing the first and second compounds.

The invention will be described hereinafter in moredetail and by way of example with reference to theaccompanying drawings in which

Fig. 1 is a schematic représentation of a firstembodiment of the System of the invention prior todrilling a new wellbore section;

Fig. 2 schematically shows the embodiment of Fig. 1during drilling of the new wellbore section;

Fig. 3 schematically shows a drilling device used inthe System of Figs. 1 and 2, and indicated as detail I inFig. 2;

Fig. 4 schematically shows a perspective view of partof the drilling device of Fig. 3; and

Fig. 5 schematically shows a second embodiment of thedrilling System of the invention for different stepsa)-f) of operation thereof.

In the detailed description like reference numeralsrelate to like components.

Referring to Fig. 1 there is shown a borehole 1formed in an earth formation 2, the borehole 1 includinga main wellbore 4 and an initial section of a branchwellbore 6 extending from a junction 8 of the mainwellbore 4 in deviated direction thereof. A packer 10 isarranged in the branch wellbore 6 a short distance fromthe junction 8, which packer 10 is provided with a firstand a second longitudinal through-bore (not shown). Awellhead 12 is arranged at the earth surface 14, on topof the main wellbore 4. A first and a second fluidpassage in the form of respective tubings 16, 18 extendfrom the wellhead 12 via the main wellbore 4 and thebranch wellbore 6 to the packer 10. The tubings 16, 18are sealingly connected to the packer 10 in a manner thatthe first through-bore forms a continuation of the first 4 012299 tubing 16 and the second through-bore forms a continuation of the second tubing 18. A device in the form of drilling device 20 ispositioned in the branch wellbore 6 immediately below thepacker 10, the drilling device having a first injectiontube in the form of tail pipe 22 and a second injectiontube in the form of tail pipe 23. Tail pipe 22 extendsinto the first through-bore of the packer 10, in asealing relationship therewith, and tail pipe 23 extendsinto the second through-bore of the packer 10, in asealing relationship therewith. The drilling device isprovided with a rotary drill bit 24 and an electric motor(referred to hereinafter) arranged to drive the drillbit 24.

The first and second tubings 16, 18 are at theirrespective upper ends connected to a control unit 25arranged at the earth surface 14, The control unit 25includes a three-way valve 26 to which the upper end ofthe first tubing 16 is connected, the valve 26 having aprimary position in which the valve 26 provides fluidcommunication between the first tubing 16 and a primarysupply conduit 28, and a secondary position in which thevalve 26 provides fluid communication between the firsttubing 16 and a secondary supply conduit 30. The primarysupply conduit 28 is in fluid communication with a fluidréservoir 32 filled with water, and is provided with apump 34 for pumping water from fluid réservoir 32 intothe first tubing 16. The secondary supply conduit 30 isin fluid communication with a réservoir 36 containing afluidic compound A, and is provided with a pump 38 forpumping fluidic compound A from réservoir 36 into thefirst tubing 16. The control unit 25 furthermore includesanother three-way valve 40 to which the upper end of thesecond tubing 18 is connected, the valve 40 having aprimary position in which the valve 40 provides fluid 5 012299 communication between the second tubing 18 and a discharge conduit 42, and a secondary position in whichthe valve 40 provides fluid communication between thesecond tubing 18 and a tertiary supply conduit 44. Thedischarge conduit 42 débouchés into a shale shaker 46having a fluid outlet 48 debouching into a tank 50, and adrill cuttings outlet 52 debouching into a container 54.The tank 50 is in fluid communication with the fluidréservoir 32 via a pipe 56. The tertiary supplyconduit 44 is in fluid communication with a réservoir 58containing a fluidic compound B, and is provided with apump 59 for pumping fluidic compound B from réservoir 58into the second tubing 18. Compounds A and B are selectedsuch that upon intermixing of A and B a composition C isformed which chemically reacts so as to harden andthereby to form a solid or elastomeric compound.

The control unit 25 furthermore includes an electricpower supply 60 arranged to supply electric power to theelectric motor of the drilling device 20 via a conductor 62, a reel 64 and an electric cable 66 spooledonto reel 64. The cable 66 extends through thewellhead 12, the first tubing 16, the first through-boreof packer 10 and tail pipe 22, to the electric motor ofthe drilling device 20.

Reference is further made to Fig. 2 showing thedrilling device 20 after drilling a new section 68 ofbranch wellbore 6. A first conduit 70 and a secondconduit 72 extend through the newly drilled wellboresection 68 between the packer 10 and the drillingdevice 20, whereby the first conduit 70 provides fluidcommunication between the first through-bore of thepacker 10 and tail pipe 22, and the second conduit 72provides fluid communication between the second through-bore of the packer 10 and tail pipe 23. The space in thenewly drilled wellbore section 68 between the 012299 conduits 70, 72 on one hand and the borehole wall on theother hand is filled with a body of drill cuttings 74.

The cable 66 is partly unreeled from reel 64 and extendsfurther, compared" to the situation of Fig. 1, from the 5 first through-bore of packer 10 via the first conduit 70 and tail pipe 22, to the electric motor.

Reference is further made to Figs. 3 and 4schematically illustrating the drilling device 20 in thenewly drilled wellbore section 68. The drilling device 20 10 has a tubular housing 80 provided with a sleeve 82 arranged around the housing, the housing 80 being axiallyslideable relative to the sleeve 82 for a selectedstroke. The housing 80 and the sleeve 82 are providedwith electrically operated thruster means (not shown) for 15 selectively thrusting the housing 80 relative to the sleeve 82 in axially forward or backward direction. Thesleeve 82 is provided with a set of radially extendiblepads 84 and electrically operated activating means (notshown) for selectively radially extending or retracting 20 the pads 84. A cuttings press in the form of a circular plate 86 is arranged at the end of the housing oppositethe drill bit 24 and extends in transverse direction ofthe housing 80. The cuttings press 86 has a diametersubstantially equal to the wellbore diameter and is 25 provided with a plurality of sieve openings 88 arranged in a radially outer portion of the cuttings press. Thetail pipes 22, 23 extend from the cuttings press 86 awayfrom the housing 80 and into the respective first andsecond conduits 70, 72 whereby the far end of the tail 30 pipes 22, 23 are indicated by respective reference signs 90, 92.

The housing 80 is provided with a fluid passageindicated by line 94. The fluid passage 94 passes fromtail pipe 22 via a heat-exchanger 96 to tail pipe 23, and 35 is provided with a pump 95 for pumping fluid through the 012299 fluid passage 94 in the direction from tail pipe 22 totail pipe 23. A cooling fluid loop 98 filled with coolingfluid passes through the heat-exchanger 96 and throughthe drill bit 24, which cooling fluid loop 98 is providedwith a pump 100 for pumping cooling fluid through thecooling fluid loop 98.

The housing 80 is furthermore provided with twocontainers 102, 104 and a mixing chamber 105.

Container 102 is internally provided with a bladder 106dividing container 102 into a primary containerportion 108 containing fluidic compound A and a secondarycontainer portion 110 containing water. Container 104 isinternally provided with a bladder 112 dividingcontainer 104 into a primary container portion 114containing compound B and a secondary containerportion 116 containing water. Each tail pipe 22, 23 isprovided with a set of injection nozzles 118 forinjecting composition C into the wellbore section 68,arranged at a distance L from the respective ends 90, 92of the tail pipes 22, 23, the nozzles of each tailpipe 22, 23 debouching into an annular recess 120, 122provided in the outer surface of the respective tailpipe 22, 23. Mixing chamber 105 has an inlet 124 in fluidcommunication with container portions 108, 114 byrespective conduits 126, 128, and an outlet 130 in fluidcommunication with the injection nozzles by conduits 132,134 (indicated by dotted Unes) extending through therespective tail pipes 22, 23.

Conduit 126 is connected to fluid passage 94 via athree-way valve 133 selectively opérable between aprimary position in which the valve 133 prevents fluidcommunication between conduit 126 and fluid passage 94,and a secondary position in which the valve 133 directs astream of fluid entering fluid passage 94 at tail pipe 22into conduit 126. 012299

Conduit 128 is connected to fluid passage 94 via avalve 135 selectively opérable between a closed positionin which valve 135 prevents fluid communication betweenconduit 128 and fluid passage 94, and an open position inwhich valve 135 allows fluid communication betweenconduit 128 and fluid passage 94.

Container portion 110 is connected to fluidpassage 94 by a conduit 136 provided with a pump 138 forpumping water from fluid passage 94 into containerportion 110. Conduit 136 is, at the downstream side ofpump 138, connected to fluid passage 94 via a three-wayvalve 140 selectively opérable between a primary positionin which the valve 140 prevents fluid communicationbetween conduit 136 and fluid passage 94, and a secondaryposition in which the valve 140 provides fluid communication between conduit 136 and fluid passage 94.

Container portion 116 is connected to fluidpassage 94 by a conduit 142 provided with a pump 144 forpumping water from fluid passage 94 into containerportion 116. Conduit 142 is, at the downstream side ofpump 144, connected to fluid passage 94 via a three-wayvalve 146 selectively opérable between a primary positionin which the valve 146 prevents fluid communicationbetween conduit 142 and fluid passage 94, and a secondaryposition in which the valve 146 provides fluid communication between conduit 142 and fluid passage 94.

Furthermore, fluid passage 94 is connected to aconduit 148 provided with a valve 150 for selectivelyproviding fluid communication between fluid passage 94and the exterior of the housing. A Moineau pump 152 is provided in the housing 80, andis arranged to be driven by the electric motor (indicatedby reference sign 153, Fig. 3). The Moineau pump 152 hasan inlet (not shown) in fluid communication with thefront end of the drill bit 24 by means of an inlet 012299 passage 154 extending through the drill bit, and anoutlet (not shown) in fluid communication with an outletpassage 156 debouching in wellbore 68 immediately behindthe cuttings press 86. Outlet passage 156 is connected tofluid passage 94 by a three-way valve 158 for selectivelydiverting at least part of a stream pumped by the Moineaupump 152 through the outlet passage 156, into fluidpassage 94.

The housing 80 has a hydrocarbon fluid inlet 160 influid communication with fluid passage 94 by aconduit 162 provided with a valve 164.

The valves 133, 135, 140, 146, 150, 158, 164, thepumps 95, 100, 138, 144, the thruster means and theactivating means ail are arranged to be electricallycontrolled from a control board (not shown) of thecontrol unit 25 by means of suitable electric signaistransmitted to the drilling device via cable 66.

Referring to Fig. 5 there is shown the secondembodiment of the drilling System of the invention. Thisembodiment includes a drilling device 200 which issubstantially similar to the drilling device 20 of thefirst embodiment, however with the différence that thedrilling device 200 has two sleeves 202, 204 arrangedaround the housing 80 instead of the sleeve 82 of thefirst embodiment, and that the cuttings press is attachedto the rear end of sleeve 202 instead of to thehousing 80. Furthermore, the housing 80 is axiallyslideable relative to each sleeve 202, 204, and eachsleeve 202, 204 is provided with a set of independentlycontrollable pads 84.

During normal operation of the drilling device 20 themain wellbore 4 and the initial section of the branchwellbore 6 hâve been drilled using a conventional drillstring. The packer 10 with the drilling device 20connected thereto and the first and second tubings 16, 18 012299 10 hâve been installée! in the borehole 1 in the arrangementindicated above with reference to Fig. 1. Then, in orderto further drill the branch wellbore 6, power supply 60is operated so as to provide electric power via '5 conductor 62, reel 64 and cable 66 to the drilling device 20 so as to induce the electric motor 153 torotate the drill bit 24, to induce the activating meansto radially extend the pads 84 against the borehole walland to induce the thruster means to thrust the housing 80 10 axially forward relative to the sleeve 82. By the combined actions of the rotating drill bit 24, thethrusting action of the thruster means, and the anchoringaction of the pads 84 against the borehole wall, thebranch wellbore 6 is deepened. Additional thrust force is 15 achieved by the cuttings press 86 pushing against the body of drill cuttings 74.

Simultaneously with operating the power supply 60,pump 34 is operated so as to pump a stream of water fromthe réservoir 32 via the primary supply conduit 28 and 20 the first tubing 16 (whereby valve 26 is in its primary position) into fluid passage 94 of the drillingdevice 20. The stream of water passes through the fluidpassage 94 and flows via the tail pipe 23 and the secondtubing 18 to the shale shaker 46. From there the water 25 flows via tank 50 and pipe 56 back into fluid réservoir 32. Simultaneously with operating pump 34,pump 100 is operated so as to pump cooling fluid throughthe cooling fluid loop 98. It is thereby achieved thatheat generated by the drilling action of the drill bit 24 30 is dissipated by the cooling fluid to the stream of water, whereby the heat transfer to the stream of watertakes place in the heat-exchanger 96.

The Moineau pump 152 is driven by the electricmotor 153 and thereby pumps a stream of drill cuttings 35 resulting from the drilling action of the drill bit 24, 012299 11 and earth formation fluid via inlet passage 154 intooutlet passage 156 and from there into the new wellboresection 68 immediately behind the cuttings press 86. Inthis manner the body of drill cuttings 74 with formation '5 fluid in the interstitial spaces is formed in the wellbore section 68. If necessary or desired, part of thedrill cuttings is discharged into the water strearaflowing through fluid passage 94 by controlling three-wayvalve 158 accordingly. The drill cuttings discharged into 10 fluid passage 94 are removed from the stream of water by the shale shaker 46, and subsequently deposited intocontainer 54.

Furthermore, simultaneously with operating the powersupply 60, the pumps 138, 144 are operated so as to pump 15 water into the respective container portions 110, 116. As a resuit compound A is induced to flow from containerportion 108 via conduit 126 into the mixing chamber 105,and compound B is induced to flow from containerportion 114 via conduit 128 into the mixing chamber 105. 20 The composition C thus formed in the mixing chamber 105 flows via conduits 132, 134 to the sets of nozzles andfrom there into the annular recesses 120, 122 of therespective tail pipes 22, 23. For each tail pipe 22, 23,composition C thereby flows around the tail pipe, between 25 the annular recess 120, 122 and the tail pipe end 90, 92, and forms an annular layer of composition C with drillcuttings embedded therein. Composition C slowly hardensand thereby forms the solid or elastomeric compoundreferred to above. The layers of solid or elastomeric 30 compound thus formed, with drill cuttings embedded therein, form the respective first and secondconduits 70, 72. It will be understood that in thismanner, during forward movement of the drilling device 20through the new wellbore section 68 as drilling proceeds, 35 the conduits 70 72 are continuously extended. The 01 2299 12 hardening time of composition C is selected such thatcomposition C substantially hardens during the timeneeded to deepen the wellbore section 68 a furtherlength L (cf. Fig. 3).

In order to compact the body of drill cuttings 74,the drilling process is stopped at regular drillingintervals and the thruster means is controlled in amanner that the housing 80 is thrusted axially backwardand thereby pushes the cuttings press 86 against the bodyof drill cuttings 74. Any excess formation fluid présentin the body of drill cuttings thereby flows through thesieve openings 88 into the annular space between thedrilling device 20 and the wellbore section 68.

After drilling a section of wellbore 68 equal inlength to the stroke of the housing 80 relative to thesleeve 82, drilling is stopped, the pads 84 areretracted, and the thruster means is induced to move thesleeve 82 axially forward relative to the housing 80 oversaid stroke. The pads 84 then are again radially extendedso as to become firmly anchored against the wellborewall, and drilling is resumed for a further stroke of thehousing 80. This process is repeatedly continued untilthe desired depth of the new wellbore section 68 isreached.

When it is desired to refill container portion 108with compound A, the following steps are taken. Drillingis stopped, pumping of water into tubing 16 is stopped,and the valves 26, 133, 140 are put in their respectivesecondary positions. A stream of compound A is thenpumped into the first tubing 16 by operating pump 38,which stream of compound A thereby flows via conduit 70,tail pipe 22, fluid passage 94, valve 133 and conduit 126into container portion 108. Part of the water présent incontainer portion 110 is thereby expelled via conduit 136and valve 140 into fluid passage 94. 012299 13

When it is desired to refill container portion 114with compound B, the following steps are taken. Drillingis stopped, pumping of water into tubing 16 is stopped,valves 40, 146 are put in their respective secondarypositions, and valve 135 is opened. A stream ofcompound B is then pumped into the second tubing 18 byoperating pump 59, which stream of compound B therebyflows via conduit 72, tail pipe 23, fluid passage 94,valve 135 and conduit 128 into container portion 114.

Part of the water présent in container portion 116 isthereby expelled via conduit 142 and valve 146 into fluidpassage 94.

In case it is desired to supply water, or otherdrilling fluid, into the lower part of wellbore 68,valve 150 is opened. As a resuit water, or such otherdrilling fluid pumped into the first tubing 16, flows viaconduit 148 into the space between the housing 80 and thewall of the wellbore 68.

After the drilling device has arrived in the targetearth formation zone containing hydrocarbon fluiddrilling is stopped and the drilling device 20 is left inthe wellbore. Hydrocarbon fluid is then produced from theearth formation to surface by opening valve 164 followingwhich hydrocarbon fluid enters the conduit (s) 70, 72 viainlet 160 and conduit 162. Alternatively hydrocarbonfluid can enter the conduit(s) 70, 72 via perforations(not shown) created in the conduit(s) 70, 72.

Normal operation of the drilling device 200 issimilar to normal operation of drilling device 20, exceptwith respect to forward movement thereof which isdescribed below with reference to sequential steps a)-f)(Fig. 5) during normal operation.

In step a) the sleeves 202, 204 are located atopposite sides of the housing 80, with the pads 84radially extended against the borehole wall. 012299 14

In step b) the pads 84 of sleeve 202 are retractedand the drill bit 24 is operated to drill a new sectionof the wellbore 6. During such drilling the sleeve 202moves forward together with housing 80.

In step c) the sleeve 202 is thrusted axiallybackwards so as to push the cuttings press 86 against thebody of drill cuttings 74 and thereby compact the drillcuttings, while the drill bit 24 remains in contact withthe bottom of the wellbore. Excess fluid présent in thebody of drill cuttings thereby flows through the sieveopenings 88 into the annular space between the drillingdevice 200 and the wellbore wall.

In step d) drilling of the new wellbore section isproceeded by operation of the drill bit, similarly tostep b).

In step e) the sleeve 202 is again thrusted axiallybackwards so as to push the cuttings press 86 against thebody of drill cuttings 74 and thereby compact the drillcuttings, while the drill bit 24 remains in contact withthe bottom of the wellbore, similarly to step c).

In step f) the pads of sleeve 204 are retracted andthe sleeve 204 is induced to axially slide forward untilthe position of step a) is reached. Thereafter, steps a)-f) are repeated.

Preferred compounds Ά and B are those available underthe trade name SYLGARD 170 fast cure (A&B) from thecompany Dow Corning, whereby compound A has a Platinumcatalyst and compound B contains a retarder. Thecomposition C formed by intermixing A and B is a siliconerubber of which typical curing times are 10 minutes at21 °C, and 0.3 minutes at 36 °C.

Instead of applying compounds A and B which form asilicone rubber, compounds A and B can be selected toform composition C in the form of a thermosetting resin. 15 01229g

During drilling the drilling device 20, 200 can besteered in a desired direction by extending the pads 84in manner that the drilling device becomes tilted in thewellbore.

Claims (16)

1. - 16 - C L A I M S

   1. A System for creating at least one conduit in aborehole formed in an earth formation, the Systemcomprising a device which includes: movement means for moving the device in longitudinaldirection through the borehole; and injection means for injecting a hardenable substanceinto the borehole so as to form, for each said conduit, alayer of hardened substance in the borehole behind thedevice, said layer defining the conduit; the Systemfurther comprising control means for controlling the rate of injectionof said substance by the injection means so as tocorrespond with the rate of movement of the devicethrough the borehole by the movement means.
2. 2. The system of claim 1, wherein the injection means isarranged to inject the hardenable substance into theborehole so as to form a cladding of the borehole wall.
3. 3. The system of claim 1 or 2, wherein the injectionmeans includes, for each said conduit, an injection tubeextending from the rear end part of the device into therespective conduit in a sealing relationship therewith.
4. 4. The system of claim 3, wherein each injection tube isprovided with at least one injection nozzle for injectingsaid hardenable substance into the borehole, eachinjection nozzle being arranged a selected distance fromthe end of the injection tube opposite said rear end partof the device.
5. 5. The system of claim 4, wherein each injection nozzledébouchés into an outer annular recess provided at theinjection tube. 17 012299
6. 6. The System of any one of daims 1-5, further comprising a remote control unit for controlling thedevice, the remote control unit being in fluidcommunication with the device via each said conduit.
7. 7. The System of claim 6, wherein the System is suitableto create a first said conduit and a second said conduit,and wherein the System further comprises pumping meansfor pumping a stream of fluid from the control unit viathe first conduit to the device and from the device viathe second conduit to the control unit.
8. 8. The System of claim 7, wherein the device is providedwith drilling means for deepening the borehole and heattransfer means arranged to transfer heat generated by thedrilling means to said stream of fluid.
9. 9. The System of claim 8, wherein the device furtherincludes cuttings transport means for transporting astream containing drill cuttings generated by thedrilling means from the front end part of the device tothe rear end part thereof and for depositing the streamcontaining drill cuttings into the borehole behind thesaid rear end part.
10. 10. The System of claim 9, wherein the device is providedwith a cuttings press arranged to press against a body ofdrill cuttings formed of drill cuttings deposited behindthe rear end part of the device.
11. 11. The System of claim 10, wherein the cuttings pressincludes a sieve for passage of borehole fluid from thebody of drill cuttings into an annular space formedbetween the device and the borehole wall.
12. 12. The System of any one of daims 9-11, wherein thecuttings transport means is arranged to selectivelyinduce at least part of the stream containing drillcuttings to flow into the second conduit.
13. 13. The System of any one of daims 1-12, wherein theinjection means includes a first container containing a 18 012299 first compound, a second container containing a secondcompound and a mixing chamber for mixing the first andsecond compounds, the hardenable substance being formedfrom a mixture including said first and second compounds.
14. 14. The System of claim 13 when dépendent on claim 7, wherein the device includes means for selectivelytransferring the first compound from the first conduit tothe first container, and for selectively transferring thesecond compound from second conduit to the second 10 container.
15. 15. The System of any of daims 1-14, wherein said devicecomprises a hydrocarbon fluid inlet for transferringhydrocarbon fluid from the earth formation via said atleast one conduit to surface.
16. 16. The System substantially as described hereinbefore with reference to the accompanying drawings.