US3747696A - Subterranean slurry mining apparatus - Google Patents

Abstract

A bit attached to a tool string is used for drilling a hole from the ground surface into or through a subterranean deposit of granular ore. Within the tool string is a passage through which fluid flows to the bit while drilling. Valve means positioned within the passage are controllable from the ground surface for diverting the flow of fluid from the bit to an eductor located above the bit for mining operation. A nozzle in the tool string, located above the eductor, is controllable from the ground surface to discharge a jet stream of fluid radially outward from the tool string for breaking up the ore matrix. Then the eductor pumps a slurry mixture of fluid and granular ore through the tool string to the ground surface.

Description

Wenneborg et al.

[ July 24, 1973 SUBTERRANEAN SLURRY MINING APPARATUS Inventors: William Z. Wenneborg, Pocatello,

Idaho; Bobby R. Payne, Charleston, W. Va.; Philip R. Bunnelle, Santa Clara, Calif.

Assignee: FMC Corporation, New York, N.Y.

Filed: June 1, 1971 Appl. No.: 148,501

US.Cl 175/87, 175/213, 175/215, 175/67, 299/17 Int.Cl E21b 7/18 Field of Search 299/17; 175/422, 175/213, 231,217,215, 87, 324, 65

References Cited v UNITED STATES PATENTS 3,439,953 4/1969 Pfefferle 299/17 Primary Examiner-Marvin A. Champion Assistant Examiner-Richard E. Favreau Attorney-Nicholas DeBenedictis, J. W. Edwards, Eugene G. Seems and Pauline Newman [57] ABSTRACT A bit attached to a tool string is used for drilling a hole from the ground surface into or through a subterranean deposit of granular ore. Within the tool string is a passage through which fluid flows to the bit while drilling. Valve means positioned within the passage are contro1- lable from the ground surface for diverting the flow of fluid from the bit to an eductor located above the bit for mining operation. A nozzle in the tool string, located above the eductor, is controllable from the ground surface to discharge a jet stream of fluid radially outward from the tool string for breaking up the ore matrix. Then the eductor pumps a slurry mixture of fluid and granular ore through the tool string to the ground surface.

PIITENTED 3. 747. 696

sIIazI 01 or 10 SLURRY INVENTORS WILLIAM LWENNEBORG BOBBY R. PAYNE BY PHILIP R. BUNNELLE ATTORNEYS PATENIED JUL 24mm 3, 7, 595 sum 02 0F 10T'IE 1 PAIENTED m 24.913 3.141. 696

SHEET U HJF 10 T'IE EI PATENIED JUL24|975 3. 74']. B96

SHEET 05HF 10 PATENTEU JULZMW 3. 747'. 696

SHEET 07 HF 10 'PATENTED 3.747. 696

SHEET D80! 10 SLURRY 4 11%.

111% WATER EL PAIENTED 3. 747. 696

SHEET 09m 10 F'IEL1'7 l SUBTERRANEAN SLURRY MINING APPARATUS BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to mining underground deposits of granular ore, such as phosphates, by deep-well hydraulic apparatus and more particularly to a combination well-drilling and mining tool for extracting granular ore from subterranean beds.

2. Description of the Prior Art Known methods for deep-well mining of granular ore, such as phosphates, require pre-drilling a well and lining the side walls with mud or a casing. Then, a mining tool is inserted through the well casing for disintegrating ore therebelow by jetting water into the matrix. A slurry mix is formed and pumped upward through the mining tool to the ground surface. Such methods are expensive because of costs of lining the hole, assembling and disassembling the drill pipe string, and assembling and disassembling the miningtool.

US. Pat. No. 3,311,414 discloses a well drilled by a mining tool itself without predrilling. Such use of the mining tool is suitable only where no layer of limestone or cap rock covers the phosphate matrix. Normally, there is such a layer and the hole must be predrilled and mudded before insertion of the mining tool.

US. Pat. No. 3,155,177 shows apparatus for underreaming a well that can also be used to bore-deeper in the well. Electric operated valves convert the apparatus from drilling operation to under-reaming operation.

U. S. Pat. No. 1,851,565 shows a mining apparatus that is inserted into a pre-drilled hole. A mining agent is projected from a nozzle to fluidize the substance mined and the accumulated mixture is lifted by an injector upward through the mining apparatus to the ground surface. No provision is made for drilling with the mining apparatus.

In order to drill from the ground surface through any stratum to reach a deposit of granular ore, it is desirable to use a rotary typedrilling rig. Upon reaching the granular ore deposit, which can be hundreds of feet below the ground surface, it is desirable to jet a stream of fluid into the ore matrix to form a slurry mixture of ore and water. One problem encountered in developing a combination drilling and mining tool is the establishment of controls at the ground surface by which underground tool operation can be converted from drilling to mining.

SUMMARY OF THE INVENTION The presentinvention provides a combination tool for drilling to subterranean deposits of granular ore and mining the deposits at a maximum speed and with a minimum amount of tool handling. Since the tool is driven by rotary drilling equipment, it can rapidly penetrate through any stratum to reach a granular ore deposit. It is unnecessary to linethe well or pull the tool after drilling because the tool string functions both as a drilling string and a mining conduit. To convert from drilling to mining operation, the tool is controlled'from the ground surface by increasing the quantity of fluid flow into the tool. Also, an inner casing is turned'to index a distributor nozzle for directing a jet stream of fluid through a desired port in the tool outer casing to break up the granular ore matrix opposite therefrom. Should the sides of the well subside about thetool after drilling, it is unnecessary to rotate the tool outer casing in one embodiment of the invention because the mining jet can be indexed independently of the outer casing. The mining apparatus includes a bit attached to a tool string having an eductor therein located above the bit and a plurality of flow passages therethrough. Rotary drilling equipment drives the tool string and bit to a desired depth and a distributor nozzle within the tool string discharges a jet stream of fluid outward therefrom to break up a granular ore matrix thereabout. The tool string includes an outer casing and an inner casing which turns therein for indexing the distributor nozzle from a closed position between ports during drilling to open positions in alignment with ports in the outer casing for mining. The eductor has a nozzle, plugged during drilling operation, which is opened by increasing fluid flow down the tool causing pressure to build up below the nozzle. A valve seals a flow passage to the drill bit when the eductor nozzle opens, thereby divertingfluid flow to the nozzle for mining operation.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a broken sectional view in elevation of apparatus embodying the present invention for drilling a well.

FIG. 2 is a broken sectional view in elevation of the apparatus shown in FIG. 1 used for mining.

FIG. 3 isan enlarged central vertical sectional view of the swivel sub assembly shown in FIG. 1.

FIG. 4 is an enlarged central vertical sectional view of the tool head assembly shown in FIG. 2.

FIG. 5 is a section taken on theline 55 of FIG. 4.

FIG. 6 is a broken longitudinal section of a typical tool section. l

FIG. 7 is a view looking in the direction of arrows 7-7 in FIG. 6.

FIG. 8 is a view looking in thedirection ofarrows 88 in FIG. 6.

FIG. 9 is an enlarged central vertical section of the distributor shown in FIGS. 1 and 2.

FIG. 10 is a section taken on line 10-10 of FIG. 9.

FIG. 11 is a perspective view of the inner distributor with portions broken away to show underlying structure.

FIG. 12 is an enlarged central vertical section of the eductor nozzle and tool bit valve shown in FIGS. 1 and 2.

FIG. 13 is a perspective view of the eductor nozzle housing.

FIG. 14 is a section taken on line l4-14 of FIG. 9.

FIG. 15 is a section taken on line 15l5 of FIG. 14.

FIG. 16 is a diagrammatic view of a modified form of the invention shown in FIGS. ll5..

FIG. 17 is an enlarged vertical section through the modified tool head assemblyshown in FIG. 16.

FIG. 18 is an enlarged vertical section through the modified mining nozzle shown in FIG. 16..

FIG.19 is an enlarged vertical section through the modified eductor nozzle plug and tool bit valve shown in FIG. 16. i j

FIG.- 20 is a section taken on line .20-20 of FIG. 19.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, the mining apparatus includes adrill bit 20 attached to atool string 21 that is driven by a portablerotary-type drilling rig 22. The drill bit can be any conventional type for a rotary drill but preferably would havepivotable cutter arms 20a that collapse within the body of the bit when the tool string is lifted. A suitable bit is manufactured by Servco, PO. Box 20212, Long Beach, California, and known as the Servco Model B Drilling-Type Hole Opener. The drilling rig has amast 23 supported on a pair ofskids 24 and 25. While skids have been shown, the drill mast could be supported on a barge or other movable mount for over-water operation or mounted on movable units such as wheeled or crawler type vehicles for land operation.

Aplatform 26 has e'nds slidably engageable withtracks 27 and 28 that extend vertically onmast 23. Mounted to the platform is aswivel 29 coupled by a hanger 30 to acable 31 which raises or lowers the platform on the mast. A rotative portion of the swivel extends through an' opening in the platform and alarge sprocket 32 is keyed thereto beneath the platform. The sprocket is driven through achain 33 by amotor 34 mounted on the platform. Since the platform and swivel for rotating the tool string can be elevated on the mast, it is possible to begin drilling a hole with the bit at ground surface without using a starting tool.

Tool string 21 is connected to the rotative portion ofswivel 29 by aswivel sub-assembly 35 and drilling fluid is supplied by ahose 36 to agooseneck 37 then through the swivel and swivel sub-assembly to the tool string. The swivel sub-assembly, shown in FIG. 3, has astub end 40 adapted for coupling with the rotative portion of the swivel and abell end 41 that couples with the tool string. Projecting outward from the bell end is acircumferential flange 42 having aguide skirt 43 bolted thereto that depends in parallel spaced relationship with the bell end.A.passage 44 extends through'the stub end to the bell end interior where a fitting 45 is located having aconical plug 46 andports 47 to direct fluid flow frompassage 44 into an annular passage 48 between the bell end and fitting. The lower end of the fitting fits telescopically into an inner tube socket of a dual pipe stand which will later be described and apacking 45a is provided thereabout. Below the conical plug is apassage 45b which enables a small quantity of drilling fluid to flow down and clean the interior of the inner tube during drilling.

Looking now at FIG. 2, atool head 49 is shown mounted ontool string 21 for mining operation. The tool head has a T-section 50 with a mining fluid orwater intake conduit 51 and abracket 52 is mounted on the T-section for supporting areducer drive motor 53. A swivel joint 54 connects the T-section with acoupling flange 55 having alarge sprocket 56 mounted thereon. The reducer drive motor drives asmall sprocket 57 andsprocket chain 58, trained about the large and small sprockets, turns the large sprocket and coupling flange. A swivel joint 59 mounted above the large sprocket is joined to a slurry dischargeconduitdensity measuring line 64 coupled at the top with apassage 65 extending inward through the coupling flange and at the bottom with a fitting 66 extending frompipe coupling 63. Apipe nipple 67 connects the fitting with a stab joint 68 that inserts into a socket end ofline 68a (FIG. 6) extending downward between inner and outer tube assemblies of the tool string. Swivel joint 54 has an upperrotative portion 70 bolted to the coupling flange and coupled byball bearings 71 to a lowerstationary portion 72 bolted to T-section 50. A union fitting 73 is attached toconduit 51 of the T-section and a threadedpipe coupling 74 joins the lower end of the T-section with an outer tube assembly of the tool string.

Tool string 21 includes a series oftool sections 75, as shown in FIGS. 6, 7 and 8, that extend from swivel subassembly 35 (FIG. 1) or tool head 49 (FIG. 2) through a layer of overburden OB to a subterranean deposit of granular ore G.O. Each tool section has anouter tube 76 and aninner tube 77. Acoupling 78, welded to the upper end of the outer tube, provides an internally threadedfemale connection 78a, while coupling 79, welded to the lower end thereof, provides a threaded male connection. Similarly, the inner tube has afemale coupling 80 at the upper end and amale coupling 81 at the lower end, however, a key 82 projecting radially inward in the female coupling interlocks in an opening 83 (FIG. 6) in the male coupling reinforced bystrap 83a so that adjacent inner tubes rotate together.

Anexternal support flange 78b oncoupling 78 is provided for supporting the tool sections when not attached to adjacent sections. Asupport ring 84, held in concentric spaced relationship byarms 85 and 87 outside offemale coupling 80,v seats on athrust bearing 84a withincoupling 78 and lugs 86, projecting outward frommale coupling 81,contact coupling 79 to maintain the lower end of theinner tube 77 in alignment within theouter tube 76 prior to engagement with an adjacent tool section.Line 68a, for measuring slurry density, fits through asupport 87 located between the support ring and female coupling and through anear 88 projecting outward frommale coupling 81.

The open annular cross-sectional area between theouter tube 76 andinner tube 77 is approximately the same as the open circular cross-sectional area within the inner tube. By approximately balancing these areas, the velocity of fluid flowing downward in the annular passage between the outer tube and inner tube is substantially the same as the velocity of fluid flowing upward within the inner tube. The head losses due to friction of fluid flowing in the tubes is minimized under this condition.

Inner tube 77 is the conduit through which a slurry mixture of granular ore is conveyed to the ground surface. By using the inner tube for the slurry passage, more clearance is provided for large modules of ore within the inner tube than would be available in the annular passage between theouter tube 78 and inner tube. Furthermore, the slurry mixture contacts only the inner tube, which can be replaced in the event of excessive wear.

Eachtool section 75 is arranged for rapid coupling with an adjacent tool section by progressive engagement ofinner tube couplings 80 and 81, key 82 andopening 83,lines 68a which are connected by stab joints, and outer tube'couplings 78 and 79. O-ring seals are fitted about innertube male coupling 81,line 68a at the stab joint, and outertube male coupling 79 to provide fluid tight connection. Threads within outer tube female connection 78a'and on the male connection ofcoupling 79 are tapered for fast engagement and disengagement.

As shown in FIGS. 1 and 2,tool string 21 includes adistributor 90, aneductor 91 and abit valve 92 that are located betweentool sections 75 andbit 20. The distributor has an outer body, as shown in FIG. 9, formed by anupper section 93 joined to lowersection 94. An internally threadedsocket 95 is provided at the top ofupper section 93 to join withmale coupling 79 of atool section 75 and an internally threaded socket 96 is provided at the bottom oflower section 94 to join with an outer casing about the eductor. Anupper ball race 97 and alower ball race 98 extend circumferentially about the interior oflower section 94, which has eight radial ports 99 (FIG. providing communication therethrough. The lower section interior surface adjacent the ports is lined with hardened wearresistant material 94a.

Distributor 90 has an inner body formed by atube 103 with afemale coupling 104 at the top and amale coupling 105 at the bottom. Within the female coupling is a key 106, similar to key 82, for locking within anopening 83 of amale coupling 81. Anozzle 107 having sets of straighteningvanes 108 and 109 fitted therein extends transversely through thetube 103 which bulges thereabout perpendicular to the nozzle as shown in FIG. 10, to maintain a certain minimum cross-sectional clearance in the tube. Acylindrical shell 110, spaced fromtube 103 by atop ring 111 and abottom ring 112, rotatably fits within the interior oflower section 94 and has alining 110a of hardened wear resistant material oppositematerial 94a. Therings 1 11 and 112 haveball races 113 and 114 positioned for alignment withball races 97 and 98, respectively.Ball bearings 115 are fed through loading holes and fitted within the ball races enabling the cylindrical shell to turn freely within the lower section of the outer distributor body while held in place axially therein. Spaced circumferentially aroundtop ring 111 arevertical ports 116 and aroundbottom ring 112 arevertical ports 117 which allow fluid to flow downwardly toeductor 91 andbit 20. Aseal 119a is positioned above the top ring while a seal 11% is positioned below the bottom ring to prevent fluid reaching the ball races. Positioned betweentube 103 andshell 110 behindnozzle 107 is adeflector 118 for directing fluid into the nozzle.

Aline 120, which couples withline 68a oftool section 75, is attached to the outside offemale coupling 104 and communicates with the interior oftube 103 for determining fluid pressure at that location to calculate slurry density. Also attached to the outside of the female coupling is anear 121, shown in FIG. 14 having internally threaded openings therein to receivebolts 122 and 123 which hold in place a connectingplate 124. Arectangular slot 125 at the edge of the connect ing plate adjacentupper section 93 is aligned over arecess 126 at the base of internally threadedsocket 95. The recess is enclosed on the interior side by aplate 127 welded to the socket base and ashear key 128 fits within the slot and recess to locktube 103 from rotation within the outer distributor body during drilling operation. In the locked position,nozzle 107 is positioned betweenports 99 to prevent fluid discharge from the nozzle during drilling and to prevent foreign matter from plugging the nozzle. A multiplicity ofrecesses 126 are provided around the socket base enabling the nozzle to be locked between any two adjacent ports.

Anouter casing 132, shown in FIG. 2, has a top portion that connects within internally threaded socket 96 (FIG. 9) ofdistributor 90, while the bottom portion is connected to aninlet housing 134 ofeductor 91. The eductor includes anozzle 145 within the inlet housing, a mixingchamber section 133 having a taperedentrance 133a connected to the inlet housing above the nozzle, and adiffuser tube 130 that extends from the mixing chamber section to a rotatable joint 131 joiningmale coupling 105.

Eductor inlet housing 134, shown in FIGS. 12 and 13, has atop ring 135 and abottom ring 136 spaced between a pair ofconduits 138 and 139 having vertical passages therein. These passages provide communication from the annular passage betweenouter casing 132 and mixingchamber section 133 to achamber 137 below the bottom ring.Radial openings 140, located between each conduit on opposite sides of the outer casing, provide communication from outside the outer casing to anaxial passage 141 that extends vertically abovenozzle 145. These radial openings provide a large slurry intake adjacent the eductor nozzle to draw in amaximum quantity of ore for suction developed. The base of the conical shaped nozzle seats within an axial opening in the bottom ring and is held in place by an overlappingretainer ring 146 bolted to the bottom ring.

Chamber 137 is enclosed by acasing 142 welded tobottom ring 136 and externally threaded at the lower end for attachment within an internally threadedsocket 143 at the top of abit coupling 144. Anaxial passage 147 extends from the chamber through the bit coupling to a threadedsocket 148 wherebit 20 is attached. Avalve seat 149 tits in the entrance to the axial passage forbit valve 92 to seatthereon and avalve cage 150 covering the bit valve within the chamber is bolted to the bit coupling. The bit valve hasguide vanes 152 that extend downward into the axial passage and aflange 153 that seals the passage entrance when seated on the valve seat. Asmall passage 154 is provided in the bit valve enabling some fluid to reach the bit during mining operation for maintaining the material thereabout in a fluidized state until the bit is raised.

Bit valve 92 is attached to aguide tube 156 that slidably flts through valve cage and has asleeve bearing 157 within the upper end thereof. Astem 158 slidably fits telescopically through the sleeve bearing into the guide tube interior where anenlarged head 159 formed on the stern prevents withdrawal of the stem from the guide tube. The stem end opposite from the enlarged head fits througheductor nozzle 145 where aplug 160 is fltted thereacross and held in place by ashear pin 161. The stem and guide tube hold the plug in position blocking the eductor nozzle and a seal under the plug prevents leakage of drilling fluid while the tool bit valve is retained in an elevated position at the top of the valve cage. The plug also prevents foreign matter which might enter theeductor inlet housing 134 during drilling operations from obstructing the eductor nozzle.

In operation,drilling rig 22 is moved to a desired location andtool string 21, withbit 20 attached, is connected to swivelsub-assembly 35. Rotation of the drill string causes the bit to open a hole andtool sections 75 are added to the tool string until a desired depth is reached. During drilling operation, a drilling fluid such as water is fed throughhose 36,gooseneck 37,swivel 29 andswivel sub-assembly 35 to an annular passage betweeninner tube assembly 77 andouter tube assembly 76. The fluid flows downward through the tool string pastbit valve 92 to the cutting heads of the bit and then upward between the outer surface of the tool string and sidewalls of the hole to the ground surface as indicated by the arrows in FIG. 1.

Upon reaching the desired depth,swivel subassembly 35 is disconnected fromtool string 21 andtool head 49 is attached thereto. Water pumped intoconduit 51 flows downwardly through the tool string betweeninner tube assembly 77 andouter tube assembly 76 tobit valve 92. As the flow is increased, pressure builds up withinchamber 137 to a predetermined amount at whichshear pin 161 breaks, openingeductor nozzle 145 and closingbit valve 92.

The downward flow intool string 21 is then directed upward througheductor nozzle 145 andinlet housing 134 to mixingchamber section 131. The jet stream through the inlet housing creates a suction that draws granular ore inward throughradial openings 140 therein. A slurry mixture of granular ore and water flows upward, as indicated by the arrows in FIG. 2, throughdiffuser tube 130,distributor 90,inner tube assemblies 77 andtool head 49 toconduit 60 from which it is discharged into a tank, not shown.

The slurry density can be calculated by directing a purging flow of water downlines 120, 68a and 64 to determine the pressure of the slurry mixture at a point abovedistributor nozzle 107. Then knowing the vertical distance from that point totool head 49 and the internal cross sectional area ofinner tube assembly 77, the density can be calculated.

Motor 53 can then be actuated to rotatesprocket 57turning chain 58,sprocket 56 andinner pipe 62. Shear key 128 is broken by rotational force andnozzle 107 is aligned to discharge through one of theports 99. A portion of the water flowing downward intool string 21 is then diverted atdeflector 118 intonozzle 107 to be discharged in a jet stream into a deposit of granular ore 6.0. When a sufficient amount of granular ore has been mined from one section of the matrix, the nozzle can be indexed to thenext port 99 and the procedure repeated until the nozzle moves through one or more complete circles. Thentool head 49 is removed andswivel sub-assembly 35 is connected for pulling the tool string. When a lifting pull is applied to the tool string, the pivotable cutter arms of the drill bit close enabling the bit to be withdrawn even though the side walls of the well have closed in about the tool string.Drilling rig 22 is moved to the next location and the procedure repeated.

Sometimes it is desirable to control the jet flow fromnozzle 107 by means other than input intoconduit 51. Such control can be achieved bymotor 53 rotatinginner pipe 62 through a drive to align the nozzle with aport 99. When the nozzle is aligned to register with the port, the jet flow discharge is at a maximum but when the nozzle is aligned between ports, there is no discharge. By positioning the nozzle in partial alignment with the port, the effective area of the port orifice is reduced and thus the flow discharge is limited. In this manner, the head of water in the well cavity about the tool can be controlled to keepdistributor nozzle 107 above water for more effective jet action.

Another embodiment of the invention is illustrated in FIGS. 16-20. A drilling andmining apparatus 170, shown in FIG. 16, has been modified for converting back and forth between drilling and mining operations. Such a tool can mine an upper ore strata, then drill to a lower ore strata which is subsequently mined without lifting the tool. Since the drilling and mining apparatus is in many ways similar to the apparatus shown in FIGS. 1-15, only those modified portions will now be described in detail and it will be understood that portions not described are similar to previously described portions.

Drilling and mining apparatus includes abit 171 attached to atool string 172 upon which atool head 173 is mounted. The tool head is fixed to aplatform 174 by a mountingring 175. A T-section 176 is bolted to the mounting ring and extends upward with ahorizontal intake conduit 177 provided for drilling and mining fluids such as water. Aslurry discharge conduit 178 extends vertically through the T-section and bends to a horizontal alignment at the discharge end.

Amotor reducer 180 mounted to the side of T-section 176 drives shafting joined by aflexible coupling 181 and extending through bearing block 182 to turn adrive sprocket 183. The drive sprocket is connected by asprocket chain 184 to a drivensprocket 185 mounted on a rotative portion oftool head 173 to whichtool string 172 is attached.

With reference to FIG. 17, mountingring 175 has a pair ofball races 187 and 188 spaced vertically along an interior face thereof. Fitting within the mounting ring is acasing 189 that has ball races on the outer face to mate with ball races in the mounting ring. The casing is rotatively suspended by ball bearings inserted in place within the ball races and centered in alignment with the axis of T-section 176.Driven sprocket 185 is fixed to the casing below the mounting ring for rotating the casing and a threadedmale coupling 190 is provided at the lowermost end of the casing for attachment totool string 172.

Within casing 189, aninner ring 191 is aligned axially withslurry discharge conduit 178 and supported bylugs 192 and 193 that project inward from the casing beneath aflange 194 on the inner pipe. Aseal 195 is provided between the inner pipe and slurry discharge conduit to make the joint therebetween fluid tight. Spacer lugs 196 and 197 maintain the inner pipe in axial alignment within the casing and amale coupling 198 at the lower end of the inner pipe fits telescopically within a female coupling 199 of an inner tube intool string 172.

Hydraulic fluid is supplied totool head 173 through aline 200 that threadably fits into T-section 176. A passage 201 extends within the T-section fromline 200 to the joint between the T-section andcasing 189. Anannular passage 202 formed betweenseals 203 and 204 is continuously in flow communication with passage 201. Adrain passage 205 is provided in the T-section to relieve excessive fluid that seeps between aseal 204a andseal 204.

Apassage 206 extends fromannular passage 202 throughcasing 189 andsupport lug 192 to aline 207 coupled withspacer lug 196. Fromline 207, apassage 208 extends throughspacer lug 196 andinner pipe 191 to aconduit 209 that passes down the interior ofmale coupling 198 overlapping female coupling 199. Anannular passage 210 formed between the male and female couplings is connected by a port withconduit 209. Extending outward from the annular passage through the female coupling and asupport lug 212 is apassage 21! to which aline 213 is connected for providing hydraulic fluid to thetool string 172.

Withintool string 172 is amining nozzle 215, shown in FIGS. 16 and 18, that extends transversely through aninner tube 216 to the outer surface of anouter casing 217. This nozzle is fixed in position between the inner tube and outer casing and to orient the nozzle, it is necessary to rotate the tool string. Alongitudinal passage 218 extends through the nozzle to anorifice 219 located at the discharge end thereof. Fluid flow from the nozzle is controlled by avalve stem 220 that slidably fits through ring guides 221a and 222b supported by straighteningvanes 221 and 222 within the longitu dlnal passage. Aseal 223 located at one end of the valve stem is adapted to blockorifice 219 when positioned therein to prevent loss of fluid and avoid plugging of the nozzle by foreign matter during drilling operation.

Near the end of valve stem 220 opposite fromseal 223 is avertical slot 224 in which the end oflever arm 225 is slidably coupled. Thus, only horizontal force is transmitted to the valve stem, though the end of the lever arm moves through an arc. The opposite end of the lever arm is pivotably connected to anear 227 fixed toinner tube 216. One end of arod 228 is pivotably connected to an intermediate point of the lever arm, while apiston 229 fixed to the opposite rod end is slidably fitted within ahydraulic cylinder 230. A coil spring1231 fits around the rod between the piston and hydraulic cylinder end adjacent the lever arm to urge the rod in the direction opposite from the lever arm. Conversely,apassage 232 connectsline 213 with the hydraulic cylinder and fluid pressure urges the piston in the opposite direction. It will be seen that the valve stem is resiliently held in aposition blocking orifice 219 until hydraulic pressure applied to the piston forces the lever arm and valve stem rearward opening the orifice.

With reference to FIGS. 16,19 and 211, aneductor 235 located withintool string 172 belowmining nozzle 215, is similar to previously describedeductor 91. However, hydraulic operated valve means control fluid flow to aneductor nozzle 236 and tobit 171. A single actinghydraulic cylinder 237 is bolted to abottom ring 238 which supports the nozzle. Adouble end rod 239 extends through the hydraulic cylinder and apiston 240 is mounted intermediately thereon within the hydraulic cylinderfFitted around the rod between the piston and alower end 241 of the hydraulic cylinder is acoil spring 242 which urges the piston upward. A seal 243 is provided at the upper end of the rod to blocknozzle orifice 244 when the spring forces the piston to atop end 245 of the hydraulic cylinder. Avalve 246, mounted at the lower end of the rod, seats withinaxial passage inlet 247 leading to the bit when the piston is forced downward to the position shown in FIG. 19. Hydraulic pressure is transmitted to the top side of the piston through apassage 248 to thetop end 245 of the hydraulic cylinder which is connected toline 213/ Operation of the embodiment of the invention illustrated in FIGS. 16-20 differs from that of the previously described embodiment as follows: During drilling, no hydraulic pressure is applied toline 200 intool head 173 sonozzle orifices 219 and 244 are blocked, whileaxial passage inlet 247 is open allowing fluid to flow tobit 171. Upon reaching a desired depth for mining, hydraulic pressure is applied toline 200 and is.

transmitted throughline 213 causingnozzle orifices 219 and 244 to be opened andvalve 246 to be closed. Drilling fluid flows downward, as indicated by solid line arrows 2511 in FIG. 19, and upward througheductor nozzle 236. Flow through the nozzle creates a suction that draws in slurry, as represented by dottedline arrows 251, which flows upward througheductor 235. The mining operation is conventional but to rotatemining nozzle 215, theentire tool string 172 is rotated by driven sprocket in the same manner as when drilling. After mining one ore strata, it may be desirable to drill down further and mine a lower strata. This can be accomplished by reducing the fluid pressure applied toline 200, allowingnozzle orifices 219 and 244 to be blocked whilevalve 246 is opened, and proceeding with drilling until the second ore strata is reached. Then fluid pressure is applied toline 200 and mining operation is resumed.

Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent that modification and variation may be made without departing from what is regarded to be the subject matter of the invention.

What we claim is: I

1. Apparatus for mining a subterranean deposit of granular ore comprising a bit, and a tool string attached to the bit for drilling a hole from the ground surface through a layer of overburden into said granular ore deposit; said tool string having a passage therein through which fluid flows to said bit during drilling operation, an eductor located in the tool string above said bit, hydraulic operated valve means located in said passage for closing off fluid flow to said bit and allowing fluid flow to said eductor for mining operation, and a slurry passage centrally situated within said tool string through which fluid and granular ore are conveyed from the eductor to the ground surface during mining operation.

2. The apparatus described inclaim 1 including means for directing some fluid downward through the slurry passage during drilling operation to keep the passage clean.

3. The apparatus described inclaim 1, wherein said bit has movable cutters extendable by applying torsional forces such that said bit opens a hole larger than the outside diameter of the tool string but retracts to less than the tool string diameter for withdrawal from the hole when the torsional forces are relieved.

4. The apparatus described inclaim 1 including a nozzle located within the tool string above the eductor for directing a jet stream of fluid outward from the tool string during mining operation to break up a granular ore matrix thereabout and means for modulating the flow of fluid from said nozzle independent of the quantity of fluid supplied to said tool string passage.

5. The apparatus defined inclaim 1 wherein said hydraulic operated valve means, held in place by. a deformable member, are actuated by deformation of the member in response to a predetermined fluid pressure developed by increasing fluid flow down the tool string passage towards the bit.

6. The apparatus defined inclaim 5 wherein said eductor includes a nozzle andsaid hydraulic operated valve means for diverting fluid flow from said bit to said eductor includes a plug fitted across said eductor nozzle, a valve fitted within said fluid flow passage to said bit, and means interconnecting saidplug and valve to maintain the nozzle plugged and the valve open until said predetermined pressure is reached whereupon said interconnecting means separate to open the nozzle and seat the valve.

7. The apparatus defined in claim 6'wherein said valve has a passage therein through which a small amount of fluid can flow to the bit during mining operation to maintain the material about the bit in a fluidized state until the bit is lifted.

8. The apparatus defined in claim 6 wherein said plug and valve interconnecting means include a valve cage fitted across the fluid flow passage to the bit for retaining the valve therein, a guide tube connected to the valve and slidably fitted through the valve cage, a stem linked to the guide tube, and a shear pin fastening the plug to the stem whereby said valve is retained in an open position within the valve cage and said plug is held over the nozzle.

9. Subterranean mining apparatus as described inclaim 1, including a nozzle located within said tool string above'the eductor for directing a jet stream of fluid outward from the tool string to break up a granular ore matrix thereabout, and means for sensing pressure of the mixture of fluid and granular ore in the slurry passage near the nozzle.

10. The apparatus described in claim 9 wherein said nozzle is rotatably mounted with rotating means such that it can 'be moved in a horizontal "plane without rotating said. tool string and bit. ,1

The apparatus described inclaim 1 including means for actuating said hydraulic operated valve means, independent of the fluid pressure in the tool string passage below the eductor.

p12. The apparatus described in claim 11 wherein said eductor, has a nozzle andqsaid hydraulic operated valve means includes a hydraulic cylinderwith a double end rod, a valve attached to one end of the rod and adapted to seat within the fluid flow passage to the bit, and a plug attached to the outer end of the rod and adapted to block avpas's age in the eductor nozzle, said hydraulic cylinder being operable to move the double end rod alternately opening the valve and plugging the nozzle or seating the valve and withdrawing the nozzle plug.

13. The apparatus described inclaim 1 including a nozzle located within the tool string above the eductor for directing a jet stream of fluid outward from the tool string during mining operation to break up a granular ore matrix thereabout and means for blocking the nozzle during drilling operation to prevent discharging fluid therefrom and plugging of the nozzle with extraneous matter.

14. The apparatus described in claim 13 wherein said nozzle has a longitudinal passage extending transversely of the tool string to an orifice at the discharge end of the nozzle, a valve stem slidably fitted'for longitudinal movement within the longitudinal passage and adapted to block the orifice when, positioned therein, and control means for slidably moving said valve stem between positions opening and blocking the orifice.

15. The apparatus described inclaim 14 wherein said control means include hydraulic controls that regulate the hydraulic operated valve rneanssimultaneously for drilling or mining operations.

'16. In subterranean mining apparatus, a tool string having an inner tube assembly and an outer tube assembly, said outer tube assembly having a plurality of radial ports spaced circumferentially thereabout at one level,

said inner tube having a nozzle therein at the level of said radial ports for directing a jet stream of fluid therethrough, and means for rotating said inner tube assembly relative to said outertube assembly and thereby indexing said nozzle withsaid radial ports.

17. In subterranean mining apparatus as described in claim 16, means'for locking saidinner tube assembly with said outer tube assembly when the nozzle is'positioned between two radial ports, saidlocking means being shearable by rotative force-applied by said rotating means to index said nozzle withsaid radial ports.

18. The apparatus described in claim l'tiwherein said nozzle is positioned in partial alignment with a port to reduce the fluid flow therethrough.

19. The apparatus described in claim 16 including ballbearings positioned between said inner and outer tube assemblies tohold the nozzle at the level of the radial ports and to reduce rotational friction between the inner and outer tube assemblies.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 3,747,696 Dated July 24, 1973 Inventor(s) William Z Wenneborg, et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 38, "ring" should read --pipe--.

Column 11, line 38, "outer" should read -other*-.

Signed and sealed this 24th day of June 1975.

SEAL) Attest:

C. E 'IARSHALL DANN RUTH C. MASON Commissioner of Patents Arresting Officer and Trademarks FORM PO-105O (10-69) USCOMWDC 503764,

* us. sovsnuusm PRINTING omcz nu O-8i6-33L

Claims (19)

1. Apparatus for mining a subterranean deposit of granular ore comprising a bit, and a tool string attached to the bit for drilling a hole from the ground surface through a layer of overburden into said granular ore deposit; said tool string having a passage therein through which fluid flows to said bit during drilling operation, an eductor located in the tool string above said bit, hydraulic operated valve means located in said passage for closing off fluid flow to said bit and allowing fluid flow to said eductor for mining operation, and a slurry passage centrally situated within said tool string through which fluid and granular ore are conveyed from the eductor to the ground surface during mining operation.

2. The apparatus described in claim 1 including means for directing some fluid downward through the slurry passage during drilling operation to keep the passage clean.

3. The apparatus described in claim 1, wherein said bit has movable cutters extendable by applying torsional forces such that said bit opens a hole larger than the outside diameter of the tool string but retracts to less than the tool string diameter for withdrawal from the hole when the torsional forces are relieved.

4. The apparatus described in claim 1 including a nozzle located within the tool string above the eductor for directing a jet stream of fluid outward from the tool string during mining operation to break up a granular ore matrix thereabout and means for modulating the flow of fluid from said nozzle independent of the quantity of fluid supplied to said tool string passage.

5. The apparatus defined in claim 1 wherein said hydraulic operated valve means, held in place by a deformable member, are actuated by deformation of the member in response to a predetermined fluid pressure developed by increasing fluid flow down the tool string passage towards the bit.

6. The apparatus defined in claim 5 wherein said eductor includes a nozzle and said hydraulic operated valve means for diverting fluid flow from said bit to said eductor includes a plug fitted across said eductor nozzle, a valve fitted within said fluid flow passage to said bit, and means interconnectinG said plug and valve to maintain the nozzle plugged and the valve open until said predetermined pressure is reached whereupon said interconnecting means separate to open the nozzle and seat the valve.

7. The apparatus defined in claim 6 wherein said valve has a passage therein through which a small amount of fluid can flow to the bit during mining operation to maintain the material about the bit in a fluidized state until the bit is lifted.

8. The apparatus defined in claim 6 wherein said plug and valve interconnecting means include a valve cage fitted across the fluid flow passage to the bit for retaining the valve therein, a guide tube connected to the valve and slidably fitted through the valve cage, a stem linked to the guide tube, and a shear pin fastening the plug to the stem whereby said valve is retained in an open position within the valve cage and said plug is held over the nozzle.

9. Subterranean mining apparatus as described in claim 1, including a nozzle located within said tool string above the eductor for directing a jet stream of fluid outward from the tool string to break up a granular ore matrix thereabout, and means for sensing pressure of the mixture of fluid and granular ore in the slurry passage near the nozzle.

10. The apparatus described in claim 9 wherein said nozzle is rotatably mounted with rotating means such that it can be moved in a horizontal plane without rotating said tool string and bit.

11. The apparatus described in claim 1 including means for actuating said hydraulic operated valve means independent of the fluid pressure in the tool string passage below the eductor.

12. The apparatus described in claim 11 wherein said eductor has a nozzle and said hydraulic operated valve means includes a hydraulic cylinder with a double end rod, a valve attached to one end of the rod and adapted to seat within the fluid flow passage to the bit, and a plug attached to the outer end of the rod and adapted to block a passage in the eductor nozzle, said hydraulic cylinder being operable to move the double end rod alternately opening the valve and plugging the nozzle or seating the valve and withdrawing the nozzle plug.

13. The apparatus described in claim 1 including a nozzle located within the tool string above the eductor for directing a jet stream of fluid outward from the tool string during mining operation to break up a granular ore matrix thereabout and means for blocking the nozzle during drilling operation to prevent discharging fluid therefrom and plugging of the nozzle with extraneous matter.

14. The apparatus described in claim 13 wherein said nozzle has a longitudinal passage extending transversely of the tool string to an orifice at the discharge end of the nozzle, a valve stem slidably fitted for longitudinal movement within the longitudinal passage and adapted to block the orifice when positioned therein, and control means for slidably moving said valve stem between positions opening and blocking the orifice.

15. The apparatus described in claim 14 wherein said control means include hydraulic controls that regulate the hydraulic operated valve means simultaneously for drilling or mining operations.

16. In subterranean mining apparatus, a tool string having an inner tube assembly and an outer tube assembly, said outer tube assembly having a plurality of radial ports spaced circumferentially thereabout at one level, said inner tube having a nozzle therein at the level of said radial ports for directing a jet stream of fluid therethrough, and means for rotating said inner tube assembly relative to said outer tube assembly and thereby indexing said nozzle with said radial ports.

17. In subterranean mining apparatus as described in claim 16, means for locking said inner tube assembly with said outer tube assembly when the nozzle is positioned between two radial ports, said locking means being shearable by rotative force applied by said rotating means to index said nozzle with said radial ports.

18. The apparatus described in claim 16 wherein said nozzle is positioned in partial alignment with a port to reduce the fluid flow therethrough.

19. The apparatus described in claim 16 including ball bearings positioned between said inner and outer tube assemblies to hold the nozzle at the level of the radial ports and to reduce rotational friction between the inner and outer tube assemblies.

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