A Versatile Rock Melting System For the Formation of Small Diameter Horizontal Glass Lined Holes

8/9/2019 A Versatile Rock Melting System For the Formation of Small Diameter Horizontal Glass Lined Holes

1/25
http://www.blackvault.com/


2/25

LA-5422-MSINFORMAL REPORT

A Versatile Rock-Melting System for theFormation of Small-DiameterHorizontal Glass-Lined Holes

Iosi alamosscientific laboratoryoff theUniversi ty off Cal i fornia

LOS ALAMOS, NEWMEXICO 87544\

UNITED STATESATOMIC ENERGY COMMISSION

CONTRACT W-740S-ENG. 36

DfSTRlBU


3/25

This report was prepared as an account of work sponsored by the UiiitedStates Government. Neither the U nited States nor the Un ited States AtomicEnergy Commission, nor any of their emptoyees, nor any of their contrac-tors, subcontractors, or their employees, makes any warranty, express or im-plied, or assumes any legal liability or responsibility for the accuracy, com-pleteness or usefulness of any inform ation , apparatus, product or process dis-closed, or represents that its use would not infringe privately owned rights.

In the interest of p rompt d istribution, this LA M S re-port was not edited by the Technical Information staff.


4/25

LA-5422-MSInformal ReportUC38ISSUED: October 1973

ientific laboratoryof h Un!vr*ity ofCalifornia

IOS AtAMOS. NEW MtXICO *7S4*

A Versati le Rock-Melt ing Sysfem for fheFormat ion ofSmall-DiameterHorizontal Glass-Lined Holes

byD . L.Sims

Work supported in part by a grant from the National Science FoundationResearch Applied to National Needs (RANN).

- N O T I C t -Tlitu icpvrt n-iipicparcd as anaccount uf worksponsored bythe (tailed Slalct Government. Nchticrhe ttnllod Sum mi! Ihe Itnilcd Stales Atomic KC*4itninbatiin. uwr any ufGhcUIticir ci>nirjclfii. &ut)c(itttrai;(ttmakes an* waffanty. cstptcworlif .it Ibbllllr "I topuiniblMly|)tfi(cne ii usefulness of any

s. n r any ofi, urtttoir employees,implied, of o-'iSumcs anyfar die accuracy,com-information, apparatus,


5/25

CONTENTS

1. Introduction 1A. Program History 18. Small-Diameter Horizontal Subterren.e System 4

12. System Description 5III. Suaeiary ef System Specifications 9IV. Description of LASL-Developec! and CommerciallyAvailable Subcomponents 9

A. General 9Q. Description of Components 9

V. Development Program 12A. Versatility of Kale-Forming Assembly 12E. Development of Attitude-Control Sensors 13C. Examples of Deviation Sensors 13D. Alignment Control Section (ACS5 15

VI. Operations 16VII. Conclusions and Discussion 17

APPENDIXAnalysis of Proposed Alignment Control Scheme 20


6/25

A VERSATILE P-OCK~MELTING SYSTEM FOR THE FORMATION OFSMALL-DIAMETER HORI2OMTAL GLASS-LIKED HOLESby

D. L. Sins

ABSTRACTRock-melting penetrators with diameters ranging from SO mm

{?. in.) to 76 mm (3 in.) have reached a stage of development atthe Los Alamos Scientific Laboratory (LASL) which suggests thatthese devices are ready for practical application. Prototyperefractory metal penetrators have formed glass-cased verticalholes of 26 m (32 ft) in a single run, and horizontal holes withdiameters up to 127 nsn (5 in.) are expected in the near future.These small horizontal holes can be usted for underground utilityconduits; for high-explosive shot emplacement; and as drainageholes to stabilize road outs or embankments.Design concepts and preliminary specifications are describedfcr a Subterrene system that forms snail-diameter horizontal holesin rock by melting and simultaneously lines the hole with glassyrock melt. Most components of the system are commerciallyavailable. Deviation sensors and alignment-control units car beadded to ensure that the holes are straight. The design andoperation of this Subterrer.e system are described and proposed

development approaches for the hole-fonning assembly are discussed.

I. INTRODUCTIONProgram HistoryRock-melting penetrators (Subterrenes)

Laboratory (LASL) to produce self-ting glass-lined holes in rock and

l (Fig. 1) by progressive melting rathernd soils melt at temperatures that

vely high: coimon igneous rocks< 1500 K, almost at the melting tempera-

re of steel {1500 to 1800 K). Thus, theng penetritors must utilize refractory

(Mo) and tungstenwhich melt at 2880 and 3650 K, respect-

y, and which, in addition, have lowthe rock-melting temperatures.


7/25

Excavation by rock- and soil-meltingnovel solutions

of the excavation Making the hole or breaking up therock. Providing structural support for

the bore hole. Removing or displacing the debrisor cuttings.liquid form of the rock- and soil-meltced by a heated penetrator introduces

into the latter two The liquid melt can be formed intoa glass lining to seal or supportthe walls of the bore hole, and Any excess liquid melt can be chilled

and formed into glass rods, glasspellets, or rock wool (Figs. 2 and3 ) ; or used to form a glass-casedcore that can be removed by presentwire-line methods.The liquid melt produced by soil- and

potential

of a complete systems approach to the pro-cesses of hole making, tunneling, and ex-cavation. The LASL development program inrock- and soil-melting techniques has al-ready demonstrated in laboratory and fieldtests an attractive advancement in practicalexcavation technology for the production ofshort, horizontal, small-diameter holes.This experience has been partially developedthrough the extensive testing of melting-consolidating penetrators (MCPs). The testsconsisted of:

Melting 50-mm (2-in.)-diam, glass-lined drain holes in Indian ruins 3at Bandelier National Monument (Fig. 4 ) . Melting a 50-mm (2-in.)-diam glass-lined vertical hole in Los Alamosvcicanic tuff to a depth of 26 i\.(82 ft) in a single run. Melting a 50-mm (2-in.)-diam glass-lined horizontal hole in Los Alamosvolcanic tuff to a length of 16 m(50 ft) (Figs. 5 and 6 ) . Melting a sequence of 76-mm (3-in.)-diam glass-lined holes in volcanictuiTf in the laboratory (Fig. 7) .

Fig. 2. Hole melted in granite specimen with an extruding penetrator. Note debris.


8/25

. Rock-wool and black glass debrisfrom holes melted by extrudingpenetrator.

4. Modular Subterrene field demon-stration unit melting drain holesat Bandelier National Monument.

Fig. 5. Consolidating Subterrene Penetrator"holing through" a 16-m (50-ft)-long horizontal hole.

Fig. 6. Stem aitd service head in positionto melt a 50-mm (2-in.)-diamhorizontal hole.


9/25

Fig. 7. Consolidating penetrator aftermelting a 76-mm (3-in.)-diamhole in os Alamos tuff. Melting stable, 50-mm-diam glass-casedholes in shales, adobe, and alluvium(Pig. 8 ) .

EP) designed for hard, dense rock. Tests

Melted 66-mm (2.5-in.)-diam holes inbasalt and granite (Fig. 2 ) . Demonstrated the capability oftailoring debris for differentapplications to meet varying debris-return systems (Fig. 3 ) .

A modularized, mobile field-test andation unit (Fig. 4) has been con-

successfully forned drainage holes in the

This test rig will be used for

additional field tests and for demonstrationsof improved consolidating and extruding pen-etrators.

In addition, LASL is currently develop-ing a 114-mm (4.5-in.)-diam, consolidating,coring penetrator that will produce a 63-ron(2.5-in.)-diam glass-encased core.B. Small-Diameter Horizontal SubterreneSystem

The coring capability for the Subterrene,together with the commercial needs for hori-V 8zontal holes for underground power lines 'and a review of reguests for information onthe rock-melting Subterrene, has promptedthe preparation of preliminary design con-cepts and specifications for a horizontalSubterrene capable of melting glass-lined,76-mm (3-in.)-diam holes to lengths of *>> 50 (165 ft) with sufficient accuracy for mostcommercial applications. Horizontal glass-lined holes cf this diameter and lengthcould be useful as:

Glass-lined drain holes for subsidedmines. Glass-lined drain holes through dikedareas to accelerate drainage afterflooding. Injection holes for burning mines. Sealed, glass-lined inspection holesin mine faces or in dax. abutments. Sealed, glass-lined inspection holesin suspected pollution areas. Underground utility conduits fortelephone, gas, water, and televisionlines. Glass-lined holes for high-explosiveshot emplacement. Drainage holes to stabilize roadcuts and embankments.

System descriptions, preliminary de-sign concepts, and detail component des-criptions are presented in the followingsections, along with indications of addi-tional development programs required toprovide subsystems that are not yet avail-able for this versatile horizontal hole-melting device. Such a device will also


10/25

A

Fig. 8. External surface of glass-lined hole melted in dry alluvium.provide necessary and valuable informationfor the development of the Geoprospector*system-

II. SYSTEM DESCRIPTIONThe components of the proposed small-

diameter horizontal Subterrene system, de-picted in Pig. 9, are similar to those of themodularized rock-melting Subterrene demon-stration unit shown in Fig. 4. These com-ponents include:

ft stem advancer. Fig. 10, that willcontinuously advance the stem by use of twoindependent hydraulic cylinders and remotelyoperated stem clamps.

A dual-tube stem consisting of aflush outer steel tube, coupled in sections,and an insulated inner copper tube. Thesetubes provide the electric-power conductors

Sea Ref. 7, p. 19,for a brief descriptionof this continuously coring tunnelprospecting device.

to the heated penetrator, circulate coolantto the hole-forming assembly (HFA), and pro-vide a force path to transfer the thrust tothe advancing melting penetrator.

Circulating, compressed-air coolant,to cool the stem, chill the glass-hole lin-ing, and form small glass pellets (or rockwool) from the excess melt produced by a UEP.This excess melt debris is carried to thesurface and ducted through the service headinto a separating and collecting station.The return coolant from a consolidating pen-etrator is ducted directly into the ambientair.

A quick-disconnect service head,Fig. 11, that connects the operational linesto the stem (i.e., electric power for thepenetrator, coolant air for glass-formingand debris removal, and sensor and instru-mentation leads).

The HFA (hole-forming assembly).Figs. 12 and 13 , which is selected to fitthe job requirement, can be assembled inter-

changeably from the following subcomponents:


11/25

Fig. 9. Horizontal Subterrene melting awater aervice hole.

RwartCiteS t m Clomp

HydraulicCywxtar

10. Small-diameter horizontal Sub-terrene stem advancer.

- A heated penetrator, to mplt rock orA melting consolidating penetratorFig. 14, is used in loose soils, al-

ty rock, and forms alining; whereas a universal extruding

(UEP) , Fig. 15, is used in densehard rock and produces rock debris.

electricalGround

Standard DualTube Stem

8 Debris

Fig. 11. Quick-disconnect service head.- A glass former, attached directly to

the penetrator, chills and forms the glasshole lining from the liquid melt. For theextruding penetrator, this unit also con-tains the components to chill the extrudateand to process the excess melt into remov-able debris.

- A centrali2er,to hold the HFA on course.- An alignment control section (ACS). to

return the HFA to course when deviation isdetected. The controlling force is orientedand applied from the surface control console.

- A deviation sensor (PS) or deviationindicator (PI) , detects deviation of theHFA from the projected center line of thehole. Signals from the DS or DI are pro-cessed and displayed on the control console.The HFA can be made up in a variety of


12/25

(o;

-P en et ra to r ^-G lass Former Stem-

i ,Central izerm h =

Deviat ion Indicator1 - S t e m( c ) f e = = = =

Deviation Sensoror Indica'or- -Al'gnment Control Sensor Cable-

Fig. 12. Hole-forming assemblies: (a)simplest HFA-penetrator, glass former,andstem; (b)addition of centralizer; (c)additional deviation indicator;(d) complete assembly with alignment control.He Purge Flow

Penstrxiror (Contolklating) Elec tr ica l Thrust .

13. System schematic for a horizon-tal consolidating and horizontalextruding Subterrene showing therequired functions of the com-ponents .

GraphiteElectrode

Electric CurrentFlow Path

S t e m

PyrographiteInsulator

POCO GraphiteReceptor

Fig. 14. Consolidating penetrator forloose soil and low-density rock.


13/25

Debris Removal ZoneCoolant I Thrust Load

DebrisExtrudateThin GlassLining

ExtrusionZoneGraphiteInsulator

Dense Rock' 'Melting Zone15. Extruding penetrator for dense rock.

, as indicated in Fig. 12, tofor a given

A complement of service units arefurnish electric power to the pen-

a, sensors, and instrumentation;to the stem advancer

em clamps (Fig. 16 ) . The coolant-airy also powers an air-oil intensifier

ency stem advance and retraction. A single control and instrumentation

for the necessarypower, hydraulic and air controls,

or displays. Sensor displays andn indications will also

Note that the proposed horizontal rock-system which forms the

ed holes in place can be assembledvarious subcomponents to produce holes

varying straightness. For example, therming assembly can:

IT

Fig. 16.

Oil to CylindersOil Return

Oil to ClampsAir

Hydraulic and air-control circuitsfor operation of horizontal stemadvancer. Melt an accessible, glass-lined hole

under obstructions or structures such asroads, highways, railroads, and canals wherehole straightness is not a major factor.This can be accomplished with a simple HFAconsisting of only a penetrator, glass for-mer, and stem, as indicated in Fig. 12(a).

Melt a very straight, accessible,glass-lined hole from an established pointto intersect a target point with a maximumterminal deviation of two hole diameters orless. This will require a HFA equippedwith a deviation sensor, a surface-operatedalignment-control unit, and a sensor signalthat can be displayed on and monitored fromthe control console by the operator[Fig. 12(d)].

The proposed system concepts, components,and specifications are detailed in thefollowing sections.


14/25

III. SUMMARY OF SYSTEM S PEC IFI CAT ION

The following list summarizes the pre-liminary specifications for a horizontalhole-melting Subterrene system:

Inside diamete r of the glas s linedhole, 76 ram (3 in .) 50 nt (164 f t ) .ole-length capability.

Rate of penetration,- For a melt-consolidating penetrator(MCP) in loose alluvial soil up to0.84 nm/s (2 in./min).- For a universal extruding penetrator(OEP) up to 0.42 nnn/s (1 in./rain).The two penetrator types are inter-changeable, are electrically powered,and use circulating air for coolingand debris removal.The glass formers and hole sizers areintegral parts of the penetrators.The maximum hole deviation is lessthan two diameters, but the systemcan be assembled in a simple versionfor less accurate operation.Deviation of the HFA from the projectedhole center line is detected by thedeviation sensor, and the amount ofdeviat ion is displayed on the contro lconsole.Directional control of the HFA is pro-vided by a differential cooling systemwhose operation is regulated at thecontrol console for high accuracy.Lesser straightness will be controlledby simple stem rotation.The hydraulic stem advancer-retractoris capable of continuous motion andis provided with remotely operatedstem clamps. Hole alignment can beset with in the ra nge of +. 0.25 rad(.15 de g) from the h or iz on ta l.The advancing stem will be a dualtube to transmit power and coolantand for debris removal when required.The stGiii will be flu sh externall yand of sectioned lengths for ease ofhandling.Melti ng power is estimated at 15 kW,and total available power should bei> 5 kW.A quick-disconnect service headis included.The single control console willincorporate controls for air supply,hydraulic and electrical power; HFAdeviation and amount of applieddirectional control; and instrumenta-tion displays.The service units to be includedare:

- Air compressor.- Alternating-current generator,engine-driven.- Alternating current-to-directcurrent converter.- Hydraulic pump, motor-driven.- Air-oil hydraulic booster.- Light truck for mobility.Service leads and hoses are suppliedas required.

IV. DESCRIPTION OF LASL-DEVELOPEDAND COMMERCIALLY AVAILABLESUBCOMPONENTS

A. GeneralThis section describes components of

the system that are either already developedor can be designed and assembled in a straight-forward manner from commercially availablepro duc ts. The demo nstr ation rig for 50-ima(2-in.)-diam penetrators has had excellentresults in initial run s. Much of this sim-ple, inexpensive modular rig (Fig. 4 ) , canbe used as the design base for the 76-mm(3-in.)-diam horizontal Subterrene. Othercomponents have been thoroughly tested bothin the laboratory and in field-test rigs.The alignment accuracy of the demonstrationrig is suffic ient for many an ticipated usesof horizontal , glass=lined holes. In fact,by intermittently rotating the stem and theHFA of 50-ront (2-in.)-diam Subterrenes whilemelting vertical (Fig. 17) and horizontal(Fig. 18) h oles, bores were produced thatwere straight to considerably better thantwo hole diam eters in 16 m of hole le ngth.

B. Description of ComponentsSpecifically, the proposed small-diam-

eter horizontal Subterrene system would con-sist of the components detailed below.

1. Stem Advance rThe stem advancer (Fig. 10) wil l

advance the stem continuously with two in-dependent, twin hydraulic-cylinder units andremotely operated stem clamps.


15/25

T T :

Fig. 17. Photograph showing degree ofstraightness in a glass-linedvertical hole.Fig. 18. Photograph showing degree ofstraightness in a glass-linedhorizontal hole.

Normal operating pressure will bo6.S MPa (1000 psi) for an advancing loadper cylinder pair of 20000 >J (4550 lb f) anda retracting pull of 28000 H (6350 lb f) . Emergency operation will use fourcylinders with a maKimuro of 13.8 MPa(2000 p si ).

The frame (head and base of eachcylinder pair) will be adapted for fasten-ing to anchor posts, and will be rigid atthe above loads.

Retraction time of a cylinder pair,with normal operating pressure using thehydraulic pump only, will be 20 t 5 s.

2. Advancing Stem The dual-tube advancing stem (Figs.

11 and 12) will be similar to that used onthe modularized, mobile rock-melting Sub-terrene demonstration unit.

The stem will be flush externallyand slightly smaller in diameter than theHFA. The inner copper tube will have aninside diameter of i> 27.5 mm (1 in .) .

The operating temperatures of thestem are estimated to be less than 600 K.Materials used in stem construction near theHFA will have an operating life of 3000 h atthis temperature. Additional stem sectionswill be constructed of conventional materials(low-carbon steel) and will operate at lowertemperatures (4CO K ) .

The stem will be assembled in lengthof 1.5 m (5 ft) and 3 m (10 ft ).

3. Service HeadThe service head (Fig. 11) will pro-

vide a quick disconnect (and connect) ofthe surface supply lines to the stem (elec-tric power, coolant, instrumentation, anddebris removal).

4. Hole-Forming Assembly (HFA)The hole-forming assembly (Fig. 12)

for the simplified small-diameter horizontalSubterrene system would be assembled fromthe following.

A heated penetrator will be selectedfor the anticipated rock or soil to be10


16/25

encountered. Melting-consolidating penetra-tore 76 mm (3 in.) in diameter (Fig. 14)will be used for melting glass-lined holesin alluvium and low-density rock, and willbe similar in design to the consolidatingpenetrators that have been developed. Uni-versal extruding penetrators, which axe in-terchangeable with melting-consolidatingpenetrators in the HFA, are used for meltingin dense or hard rock. The design and con-struction of this type penetrator is alsowell advanced. Both penetrators will pro-duce


17/25

(DS) and an alignment- control section(ACS) will have to be added to the HFA. De-

V. DEVELOP MENT PROGRAM

Versatility of Hole-Forming AssemblyThe subsyst ems (see Section III) of

ameter horizontal Subterrene

A deviation indicator, A deviation sensor, An alignment-control section.

The deviation indicators and deviation

. The se addit ional subsystem s allow a

Desired levels of performance

Assemb ly A. A heated consolidating or

[Fig. 12(a)] to melt,

util -

n misalignment . The course ofmelted hole is controlled by periodic

Assembly B. A heated penetrat or, cen-

to those of Assembly A. The centralizerholds the heated penetrator on course, al-lowing higher stem loads, increased penetra-tion rates, and longer controlled penetr a-tion. Periodic partial rotation is againused to equalize deviations due to assemblyeccentricity . The centralize r assists inthe control of penetrator s over longer andmore accurate runs such as utility conduitsfor high-vol tage supply and gr avity-se werconnectors.

Assembly C. This system consis ts of aheated penetrator, centralizer, deviationindicator , operator si gnals, and advancin gstem [Pig. 12{c)l. In addition to providingthe increased hole-alignment capability ofAssembly B, the operator is alerted wh eneverthe HPA deviates by a preset amount fromthe proposed hole center line. By indicatingto the operator the quadrant of deviation(viewed down the hole) thu operator may in-itiate a course correction by quadrant ro-tation of the advancing stem rather than byperiodic partial stem rotat ion. Continue dquadrant deviation would signal a mechanicalcause, either a change in geologic formation(boulders) or stem deformations.

Assembly D . A heated penetrator , devi-ation sensor (or deviatio n indicator), align-ment-control section, centralizer, operatorsignals, and advancing stem [Fig. 12(d)]are assembled. Thi s unit can track the de-viation of the HFA assembly from the pro -jected center line of the hole in terms ofazimuth and bearing, and display this in-formation on the control conso le. The align-ment-control section allows the operatorto turn the HFA toward the projected holecenter line. This assembly also allows theoperator to follow and to control the HFAin a predetermined deviated path. Such po-sitive control of the hole-forming assemblywill increase the capacity of the small-diameter horizontal Subterrene system for

The deviatio n indicator is used for quad-rant deviation signal and contro l.


18/25

following critical paths or intersectingsmall targets.

B. Development of Attitude-Cont rol SensorsSeveral approaches to the development

of sensors, deviation indicators, and align-ment-c ontrol systems are being investigated.The deviation indicator (01) shown concep-tually in Fig. 19 wil l flash a light onthe control console to alert tbe operatorthat the hole-forming assembly has deviateda predetermined amount in a given quadrant(viewed from the stem-advancer en d ) . Thesignal is generated whe n the cantileveredsection of the inner tube is contacted bythe outer housing after a predetermined de-flection. This approac h is similar to thatof a simple torquetrench indicator.

The development of a deviatio n sensor(DS) can choose among several possib ilitie s:

Laser optic al systems are currentlyin use for aligning tunnel-boring mach ines;however, although the HFA will probably de-viate more than one diameter in a guidance-control cycle and although the use of alaser is therefore questionable, these sys-tems will be reviewed for possible adapta-tion of the HFA.

Inertial guidance systems are widelyused for navigation and attitud e-controlsystems. These systems will also be re-viewed .

Gyrostab ilizers are extensivelyused for navigation, attitude control, and9-11bore-hole surveying. They will be re-viewed for possible applicati n for inclu-sion in the HFA. A preliminary review in-dicates that hole size and length of timeto melt a hole may restrict their use toattitude and directional control.

Surface triangulation of a seismicsource in the HFA may be a method to de-termine hole deviation . Results to datehave not been promising, but a state-of-the-art review should reveal whether sufficientprogress has been made to accurately trackan HFA.

Triaxial dc magnetom eters are inuse for attitude-sensing and navigation .In one current application the deviceis following the path of a directionaldrilling tool and signals any deviationsof a bore hole in conventional oil, gas,and water drilling, or in guiding thedrilling of life-support holes to trappedminers. A review of this system will de-termine its adaptability for HFA use.

C. Examples of Deviation SensorsTwo possibilities discussed above are

used to illustrate the sensor section ofthe HFA, the surface display, and the op-erator's use of the display to initiatecorrectiv e action (see Fig s. 19, 20 , and 2 1)An open-loop sensing and control system isconsidered adequate for the length of holespecified in Section III.

The relatively simple deviation in-dicator shown in Fig. 19 can alert theoperator if the HFA is deviating in a givenquadrant. A section of the inner tube isbuilt as an independent cantilever beam byusing a flexible bellows connec tion. Fourcontacts are placed around the inner tubewith a small initial standoff clearancefrom the tube. Deflection of the outerhousing, forced by hole deviation, willcause contact between the inner tube andone of the four conta cts. Closing of thecontact will light up a corresponding sig-nal on the control conso le. Correctiv eaction can then be initiated either by ro-tating the advancing stem to equalize me-chanical alignment, or by using an align-ment-control section in the HFA. Physicalorientation of the advancing stem is main-tained by aligning and clamping fiducialprotractors that are attached to the stemsection at the stem advancer.

A triaxial magnetometer sensor candetect rotation of its axes relative to aninitial ori'entation. Fig ure 20 showsschematically the use of a triaxial mag-netometer as the deviation sensor for a

13


19/25

Signal IndicatorConsole insert -Insulat ing Spider toFirmly HoldInner Tuba inOuter Hauling

7 J \4 C o n t a c t s - ' ^ H {

High Resistance SegmentedSignal Pickup

Cantilevar Sectionof Inner Tube

CoolantReturnOrient ing Clamp LocatedBehind Advancing Stem ClampTo Align Signal Pickup ToStarling Referance

- D e f l e c t e d O u t e rH o u s i n gP i g . 19. HPA deviation indicator.

S e n s o r

PositionO is p la y - -Pro jectedHole Center

Trloxial Signal ToMagnetometer\ Display

'SSSSSS/SSSSA.

OuterHousing Inner T u b e ' Standard Stem -Sect ionF i g . 20. Triaxial magnetometer deviation sensor.


20/25

Theto thesensor and thereturn signals

in a multiple-channel cable tonal processor. After processing, thein position of the HFA is displayed

an oscilloscope screen in thecontrolA computer can be used to plot

theexcursions of the HFA fromhole center. However, penetration rates

to determine HFA ex-by hand-calculation (Fig. 21),

andplotters.Alignment Control Section (ACS)One method of applying a realigning

to a heated penetrator whilea hole is to selectively cool one

ui Pamr/stion in mi tfi

riiesnjI

12 J

100

3050

L20

ft904 0

TcisIUP10

02S9

L2 0

N

10K

Hand CdaAMon

Fig. 21. HFA deviation plot board.

aide of theouter housing of a section ofthe hole-forcing assembly (HFA). This canbe accomplished by diverting theinlet-cool-ant flow as shown in Fig. 22. A gravity-activated .-oolant-channeling valve, rotation-ally aligned with thestem, makes itp s~sible to select theaziniuthal location othe cooled side on theadvancing housing andthus to apply directive force to the HFAfromthe control console. Construction and op-eration of such a device areoutlined inFig. 22. Thegravity-activated coolant-channeling valve is an eccentrically weighteddisk that is free to rotate on frictionlessball bearings within thecuter tube of thealignment-control section. Thus, if thestem is rotated at thesten advancer end,the coolant-channeling valve retains itsrelevant position with respect to themeltedhole. In addition to a passage for the in-ner coolant- (anddebris-) return tube, thecoolant-channeling valve has twoports: one,labeled A in Fig. 22, is for total cool-ant bypass when no corrective force is re-quired. Thesecond passage, B, is used toselectively channel thecoolant flow intoCoolant Passage C to provide an azimuthallychilled portion of theouter tube. Thiscooler region will tend to cause a deflectionof thetube,which, in turn, will generate amoment to act on thepenetrator (see Appendix)

Immediately downstream of thecoolant-channeling valve is a bulkhead with fiveports. Port A is fornormal flow bypass andis spaced between Ports E and D, two of the

Coolant Passage Br C o o l

Normal Coolant Paitogt AD-'A-'E-' A-y

Eccentric Mass -

Coolant Channallng Vein-I. Fig. 22. Alignment control section.

Worm Clais LiningCoolant Rolurn -and Debris

15


21/25

four ports (D, E, F, and 6) spaced 90 degapart for selective flow control. Thesefour ports are led through the outer housingso that all four connect with Coolant Pas-sage C. Coolant Passage C extends along oneside of the outer housing for a distancesufficient to produce the required turningforce when coolant is ducted through.

For normal flow bypass, the stem is ro-tated until Port A in the coolant-channelingvalve is in line with Port A in the bulk-head with Coolant Passage C facing up. Thisposition is narked at the stein-advancer endwith a fiducial protractor clamp placed onthe advancing stem. When deviation of theheated penetrator from the center line ofthe hole is detected and shown on the sur-face display (Fig. 2 0), the operator canmake the necessary correction. For example,if the display shows left deviation, theoperator rotates the stem 90 deg to theright, so that the coolant passage, C, ismoved to the right-hand side of the hole andPort B is aligned with Port 6 in the bulk-head; Pert A is blanked off. Differentialcooling of the outer housing will turn theHFA back toward the hole center line, atwhich time the coolant is returned to normalbypass flow by returning the stem-positionindicator at the advancer to the Passage-Cup position.

Other systems of alignment control canbe visualized, such as having three or fourequally spaced coolant passages and adjust-ing the coolant flow in the HFA with remotelycontrolled valves. The smallness of a 76-mm-diam hole and the restricted volume avail-able for HFA control suggested the conceptof a gravity-activated coolant-channelingvalve for alignment control.

VI. OPERATIONSThe components listed and described in

Sections III and IV will be selected or de-signed to be modular and interchangeable.

The HFA can be assembled in any of thefollowing configurations:

Consolidating penetrator with stescentraliz rs. Consolidating penetrator withdeviation indicator and stemcentralizers. Consolidating penetrator with

deviation indicator, stem centralizers,and alignment-control section (ACS). Extruding penetrator with any ofthe above options.

The correct HFA will be selected tofit the individual job requirements, in-cluding the desired accuracy in the loca-tion of the melted hole. When maximumaccuracy is desired, the center line of thehole can be established by conventionalmethods, e.g., by usual land-surveying asindicated in Fig. 23.

The stem advancer and support equip-ment are then moved to the starting pointof the hole. The HFA (and a section ofstem) are clamped in the stem-grippingclamps. A transit and stadia rods are usedto check alignment of the bearing and theinclination angle determined by the survey.Adjustments are made by blocking and edgingthe stem-advancer base. The support equip-ment is located as the terrain permits,with the control console close to the stemadvancer. All equipment is started, op-erated, anri serviced according to the manu-factr'ijr's instructions. Service lines areattached, and melting of the hole is started.

Stem-gripping clamps on the pairs ofadvancing hydraulic cylinders are used al-ternately: While one clamp is advancing,the other is retracting in preparation fora continuous advancing stroke. All func-tions related to advancing and retractingthe stem and the HFA are controlled fromthe console., with the exception of addir-j(or removing) additional stem sections.

When additional stem is required, theoperator:

Seduces power and coolant flow tozero.

16


22/25

OitfngSFl-Survfyor't Tron l f -

Fig. 23. Establishing the hole center line. Stops advancing pressure and releasesthe rear stem-advancing clamp,returning this clamp to the full-outposition.o Releases bladder pressure in quick-disconnect service head (QDSH). Slips off QDSH and unplugs signalleads. Adds stem section and tightensconnection after plugging-in signalleads. Slips on QDSH, replugs signal leadsto console and repressures bladder. Raises power and coolant flow toprevious values. Regrips stem and applies previousload.

The stem is retracted (when the holeis finished or for any other reason) withthe following steps; the operator:

Reduces stem load to zero. Reduces power to zero. Reverses thrust load to retract mode. Maintains coolant flow until thestem pulls freely (stem drag only). Shuts off retraction force. Reduces coolant flow to zero andremoves QDSH. Pulls out stem until the next stemconnection is accessible. Loosensand unscrews connection. Unplugs signal leads and racks stem

section.

Continues the two previous stepsuntil HFA is out of hole. Secures all equipment.

If required, the hole can then be surveyedby visual observation or instrumentation toevaluate straightness, glass-casing thick-ness, etc.

VII. CONCLDSIONS AND DISCUSSIONThe development of small-diameter Sub-

terrene rock-melting penetrators has reachedthe stage where the design of a 75-mm (3-in.diam system for forming horizontal, glass-lined holes is possible. Contacts withutility companies and requests for informa-tion from industrial firms have indicatedthe need for such a device.

A comprehensive development programwould have to address two major areas:

The development of an alignment-control subsystem. The conduct of an economic studyand a market survey.

A most attractive feature of horizontalhole-melting Subterrene systems is the ca-pability of varying the accuracy of holestraightness to match job requirements.This is achieved by including or omittingthe appropriate sections in the hole-formingassembly.

The information and experience gainedfrom the development and commercializationof the horizontal hole-melting system willbe of value to other Subterrene system de-velopments. The benefit derived can be an-ticipated to be:

Field data on service life andreliability of components, par-ticularly penetrators. Extension of the technology to themelting of holes with curved paths. Experience that will lead to hori-zontal hole-melting systems withincreased diameter and range. Adaptation of the perfected align-ment-control scheme to vertical

hole-melting systems.

17


23/25

The successful development of the

to further de-in subsequent S^.bterrene prog-

This influence is shown schematically24. In addition to valuable ex-and direct data on service lifein commercial ap-

the effort will help in formingand engineering basis for de-

and optimisation of subsequent devices.very small-diameter melting pen etrators

25 for an early prototype) canuses such as punching holes in concrete

but difficult miniaturiza-to be solved if

are to be made. In addition,

Sralt Dfc-eurSyltc s

Direct ZGTTJ ITCMfippl(fatten* forl i t i l l ! , Lines, e-.c.

C o r t r j tn ur-tcfisollfls*P.3 0nie Forraticns

Gecprospcctor

24. Effect of 75-mm-diam horizontalSubterrene system on subsequentresearch and development.

TUBULAR FLEXSTEM

contribute to the development of a Geo-14prospector, illustrated in Fig. 26, andwill offer early inputs to the solutions ofposition sensors and guidance p roblems.

Fig. 25. Early prototype of 10-mm-diamrock-melting subterrene.

POSITION SENSOR GLASS

COOLANT aPOWERFig. 26.

CORE REMOVALTUBE PACKERDRIVER MELTERCorin g .Geoprospector with position sensor and directionalguidance systems capability.


24/25

REFERENCES1. E. S. Robinson, R. M. Potter, B. B. Mclnteer, J. C. Rowley, D. E. Armstrong,R. L. Mills, M. C. Smith, Editor, "A Preliminary Study of the NuclearSubterrene", Los Alamos Scientific Laboratory report LA-4547 (April 1972).2. J. W. Neudecker, "Design Description of Melting-Consolidating PrototypeSubterrene Penetrators," Los Alamos Scientific Laboratory report LA-5212-MS

(February 1973).3. R. E. Williams and J. E. Griggs, "Use of the Rock-Melting Subterrene forFormation of Drainage Holes in Archeological Sites," Los Alamos ScientificLaboratory report LA-5370-MS (August 1973).4. R. G. Gido, "Description of Field Tests for Rock-Melting Penetration,"Los Alamos Scientific Laboratory report LA-5213-MS (February 1973).5. J. W. Neudecker, A. J. Giger and D. E. Armstrong, "Design and Developmentof Prototype Universal Extruding Subterrene Penetrators," Los AlamosScientific Laboratory report LA-5205-MS (March 1973).6. R. E. Williams, "Development of a Modularized Mobile Rock-MeltingSubterrene Demonstration Unit," Los Alamos Scientific Laboratory reportLA-5209-MS (March 1973).7. D. L. Sims, "Identification of Potential Applications for Rock-MeltingSubterrenes," Los Alamos Scientific Laboratory ueport LA-5206-MS(February 1973).8. James Paone, "Horizontal Holes for Underground Power Lines," Proc.Tunnel and Shaft Conf., Minneapolis, MN, May 15-17, 1968, pp 93-113.9. R. L. Waters, The Electro-Mechanics Company, P. 0. Box 1546, Austin, TX ,letter communications, April 1973.

10. Sperry-Sun Well Surveying Catalogue 723, "Magnetic Steering Tool", p. 4049.Sperry-Sun Well Surveying C o., P. 0. Box 36363, Houston, TX 7703611. Humphrey, Inc. Bulletin FG-1270, "Surveyor Bore Hole Directional Systems",Humphrey, Inc., 2605 Canon St., San Diego, CA 9210612. C. Ishan, Scientific Drilling Control, 4040 Campus Drive, Newport Beach,CA, personal communication, April 1973.13. L. A. Rubin, "New Survey Systems for Drilling," Telcom, Inc., McLean, VA1971.14. J. W. Neudecker, "Conceptual Design of a Coring Subterrene Geoprospector",Los Alamos Scientific Laboratory report in preparation.


25/25

APPENDIXANALYSIS OF PROPOSED ALIGNMENT CONTROL SCHEME

The parameters affecting the design andperformance of the alignment control section(ACS) proposed in the main body of the re-port can be derived by reference to Fig.A-l. The temperature difference establishedacross the diameter of the ASC by the di -verted coolant will induce a curvature inthe housing given by

1 _ a ATP ~T~' (A-l)if the unit is free to deflect [Fig. A-l(a)],here AT = effective temperature difference;

i) = radius of curvaturec. - mean coefficient of thermal

expansionD = diameter of the housing.ypical values for the projected design and

o = 6.0 x 10" 6, K"1D = 75 mm = 0.075 m

AT = 100 K.are .1 6.0 x 10 " 6 x 10 8^ SS mill -p 0.075

125 m.

0.008 m-1

Therefore, if the length, L, of the ACS unitis 1.0 m, the derivation at the end of theunit will be given by

A = = 0.0033 m = 3.3 mm.If the ASC is initially rigidly fixed by acentralizer section at one end and the pen-etrator at the other end. Fig. A - K b ) , itwill exert a moment given by

M =where

E IfP

(A-2)

E = elastic modulus of the materialfrom which the ACS is constructedI = area moment of the ACS crosssection.

Taking E = 207.0 GPa (30 x 1 0 6 lb f/in.2),the data aboveand combining Egs . (A-l) and(A-2), the moment (M) and induced stress (a)are:

M = 2.6 x 10 3 N-m (2.27 x 10 in.a = 62 MPa (9.000 lb f/in.2).

lb f)

This moment is of sufficient magnitude toinduce the required path deviation whilegenerating only low stresses in the hole-forming assembly.

Penetralor- - Glass FormerAlignment Control - ...Section I B e n I f l n a MomentM j M

V -Devlotlon Snsor

Documents

A Versatile Rock Melting System For the Formation of Small Diameter Horizontal Glass Lined Holes