US1919636A - System of mining oil shales - Google Patents

Description

July 25, 1933- s.` N. KARRlcK 1,919,636

SYSTEM OF MINING OIL SHALES Filed March 5, 1930 l 5 Sheets-Sheet l Ouf/e115 DUUDDDUUED l July 25, 1933. s. N. KARRICK SYSTEM OF MINING OIL SHALES Filed March 5, 1950 5 Sheets-Sheet 2 July 25, 1933. sf N, KARRlCK 1,919,636

SYSTEM OF MINING OIL SHALES Filed March 5, 1930 5 Sheets-Sheet 4 l//ce 7nne (J1/Wenko@ July 25, 1933. n s, N KARRICK 1,919,636

SYSTEM OF MINING OIL SHALES Filed March 5, 195o 5 sheds-sheet 5 NUMBUPEM I Patented July 25, 1933 c SAMUEL N. KABRICK, OF BLT'IMOBE, MARYLAND SYSTEM or'nmme'on. slums Application filed March 5, 1980. Serial No. 438,385.

This. invention relates to the production gases "with nitrogen vand carbon dioxide of oil from shales or coals andv particularly concerns new methods `of developing the oil shale deposits and'treati-ng the oil-forming materials underground. By my methods of operation'shale oils and fuel gases may beV produced at a fraction of the costs which must be met by other methods.

The large deposits of oil shales `of the United States occurring in Colorado, Utah and Wyoming, also in Indiana and Kentucky, contain contiguous strata of oil shales ranging from twenty-five to one hundred feet in thickness which may be distilled successfully by my method. Also'in Utal there are large deposits of suitable co'als for this treatment.

I have worked out improved mining methods for preparing the deposits for '20 treatment which take advantage of certain natural features of the deposits, namely, structure, thickness, type of material and height above the valley ioors, etc., tol obtain great economies 'in the commercial treating of the shales and handling of the products formed. F or example, 'in the oil shale areas of Colorado the richest oilgnshales are 0btained within a series of strata some fifty feet thick lying approximately 1500 feet above the valley ioors and toward the top of a precipitous face some 500 feet in height (see Fig. 1). The methods I prefer to use are hereinafter described in relation-to .these beds of shales, but are not limited thereto, nor in the precise form as shown and described.

In order to supply the necessary heat for carrying on the distillation, I introduce into contact with the shale the products of combustion from burning variable mixtures of the combustible gas formed in distilling shales. The temperature produced is governed by regulating the amount and proportions of the gas and air used and will be such 45 that the volatiles are removed from the shales and the carbon residue remaining in the spent shale is heated suliiciently high to form producer gas by interaction with the products of combustion. In this way I am able to prevent excessive dilution of the shale which would render the gases of no value for fuel purposes. Additional fuel gas is also formed by introducing air alone into contact with the hot spent shale after the oils are removed by which the residual carbon is slowly burned and transformed into producer as. The two sources of gas provide a supp y'of gaseous fuel which will be a surplus over that required for the distillation of the shale and will leave ample for generat- 1ng power by gas engines or steam plant to run fans, air compressors, pumps, dynamos, etc., for the entire shale works, refinery and camp uses.

In applying my method of mining and 'distillation to the-oilfshales of Colorado in the bodies referred to above, I produce large bodies of lump oil shale either in the form of vertical chambers or tunnels which are substantially full of the broken shale.v Only enough of the shale is removed to allow for the normal voidage of the broken shale left in the chambers. The hot gases are then passed either downward or upward throu h the chambers, or horizontally through t e tunnels. The chambers occupy nearly the full height, or thickness, of theseries of strata se ected as most advantageous to treat and are separated by partition walls of oil 8o shale of the minimum thickness that will preserve a gas-tight'separation of the chambers and yet of such minimum thiclmess that the oil shale forming the walls will be distilled simultaneously with the broken shale occupying the chambers.

In the above case I prefer to develop the shale deposit by using closely spaced vertical or sloping chambers or raises about 50 feet in height.4 This stratigraphic height has been shown in the Bureau of Mines -investigations Ato contain a series of contiguous strata which are the richest in the oil shale measures and that they vary in oil field from 20 to 65 gallons per ton of shale and the 50 95 feet will average 35 gallons per ton. In one form of preferred developmentthe chambers will be installed four in a unit on each side of and above a common service tunnel to which they all are connected by a simple 10o broken material to near t ing the adjacent chambers will not be broken through and will be of proper thickness to permit complete distillation of their contained oils. Y

The branch raises leading down from the bottom of the shale raises must be amply" steep to permit the broken rock or oil shale to run out freely as the blastin proceeds during the development work. Since the branch ralses lead down into the servicetunnel, I provide for placing mine cars under the raises to receive the rock shot down and, thereby, I avoid any hand loading of the development rock. The rock and oil shale that is removed in'wthe development work will be from 25 to 40 percent of the total shale broke en and by my gravity method of transferring the material into hars I reduce the cost of development to a minimum.

The oil shale removed from the raises is trammed to another part of the mine and dumped through a hopper and gates in the f tunnel floor leading into a distilling shaft of several hundred feet in depth. This material is separately distilled and gasilied by the same method as used in the vertical chambers referred to above.

It will be recognized from this general description that all the shale is treated underground in substantiall vertical shafts or. chambers without requlring any excavating or loading either by hand or by power operated machinery. f Also, both quantities of shale, namely, that treated in place and that removed and dumped into the distilling shafts, are subjected to the downward flow of hot gases which effects the distillation of the large and small lump material and subsequently converts much of the residual car bon of the shale into producer gas.

When the distillation and gasification treatment of the shale in the vertical chambers is completed, the supplies of gas and air are cut oif, but no veffort is made to remove. the spent shale or make further use of the chambers. However, when ,the treat-l ments of the shale in the shafts are completed, the spent material is removed by bottom discharge gates and a fresh charge is substituted and the treatments repeated. The shafts thereby serve for continuous use and Atheir construction cost, which is very low, is

nevertheless charged oif in treating many` charges of oil shale. l By reference to Fig. 1,

it will be observed that the discharge gates 0f the distilling shafts 4are so located that ample dump room is'provided for the spent shale.

The various mining methods I apply are well known and the various treating galleries are. modifications of forms of hard rock workings with which I have had experience in Utah and Nevada, but are herein adapted and improved upon to make possible the economical treating o the large deposits of oil shales, all of which methods and forms comprise my invention.

In order to make more clear the details of m invention and the forms in which it may e applied, reference is now made to the drawings forming part of this application.

IFigure 1' is a vertical section through a Fig. 7 is a plan view of the workings shown in Fig. 6. Figs. 8 and 9 areenlarged verti cal sections at right angles to each other through the treating tunnels of Figs. 6 and 7. Fig`` 10 is a vertical, longitudinal section, like in ig. 8, but in addition shows some detail of the caving method. '1 is the rock overburden lying on top of the strata of oil shale to be worked. 2 is a series of strata of oil shale which are to be worked as a body. 3 is the country rock lying below the main body of rich oil shale.

4 is a service tunnel approximately 30 feet below the bottom ofthe oil shale. This tunnel is driven in a stratum of fairly rich oil shale which occurs at this position. 5 are vertical chambers filled-With broken oil shale and, as shown, are nested together'y within the strata of pay oil shale. 6 are series of sloping branch raises which connect with the bottom of the vertical chambers and with the service tunnel 4.

7 is a vertical or inclined shaft extending downwardly several hundred feet from service tunnel 4. At the bottom of shaft 7 is located a gas-tight gate 8. Below this gate is a chute 9 by which the material discharged from the shaft is deposited on the dump below the escarpment of the mesa. Near the top of the shaft 7 is a gas-tight gate l0- through which the oil shale mined from theA chambers 5 is deposited into the shaft. Be-' low the gate 10 are connected a gaspipe 1l and air pipe 12 through which the combfstible gaseous mixture is introduced for disremesa the shale] are removed and conducted, to the condensers '(not shown). 14 is also .a vapor and gas outlet by which the volatile productsy from the chambers 5 are conducted from the mine to the condensers. ^On the outer end of connection 14 is shown an explosion door which is provided as va safety measure to obviate damage to the condensing plant in the event of mild explosions occurring within the gas tunnel.

Fig; 2 is a plan view of the workings shown in F ig'. 1 and in addition shows the present and future development areas, also a reserve shalearea. The gases and vapors coming from chambers 5 pass out of tunnel 4 by way of )connection 14. A gas barrier 16 in tunnel 4 is shown at the extreme right of the zone occupied by chambers 5 and serves to prevent the explosive gases and vaporsfrom entering the tunnels 4 The tunnels 4 are used for transportation, communicationfetc.,

. and haulage of the shale for distillation in shaft 7. The barrier 16 is advanced to the right as neufchambers are made ready for use. By this arrangement one system of tunpart of Fig. 3 are shown the preliminarysmall raises which are driven up through the body of oil shale. The shale removed from this operation is deposited in the distilling shafts 7. In dotted lines is shown a plan view of the system of branch raises by which the chambers 5 are connected with the tunnel'4.

Fig. 4 is a section in large scale of the vertical chambers and their connections with the tunnel 4. 2 is the body of oil shale and 3 is the country rocklying immediately below. An end View is also shown of the'service tunnel which passes through a stratum of medium rich oil shale.

In preparing to develop the chambers 5,

I first install the connecting raises 6 leading`from the tunnel 4 up to the base of the rich oil shale strata. The direction of the connectingraises is so governed that the vertical chambers 5 will be properly spaced from each other. Next the small raises 5 are installed and' are made to connect with the tops of the branch raises 6 and extend to approximately the top ofthe rich oil shale strata. The raises are now ready for filling with the broken shale ,which is derived by drilling and blasting the surrounding walls of the raises 5. It is essential that care be exercised in this step of the process in order to produce the required amount of broken sha e to fill the chambers with the minimum expenditure of owder while at the same time reventing reakin through the walls into e adjoinlng cham rs. In order that the chambers 5 will be filled with broken Y shale by the blasting procedure, it is necessary that the volume of the raises 5 shall be approximately 25 to 35 percent of the volume of the chambers' 5. With this in mind the spacing of the chambers is so laid out that the walls 17 between the various chambers will be of substantially uniform thickness and approximately twice the diameter of the large ,lumps of broken shale in the chambers. By this arrangeme t and method of development I am able t effect the distillation of the shale rock of the Walls simultaneously with the brokenshalewithin the chambers. I thereby make possible the extraction of the oils from much more of the shale rock than is actually mined.

Fig. 5 is a vertical section taken at right angles to Fig. 4 along the line 5 5. The chambers 5 are full of broken shale and are ready to commence the distillation of their A contained oil. The heat Vfor carrying on the distillation is herein shown as being supplied by a burning mixture of gas and air introduced by pipes 18 and 19 leading into each of the chambers at the tops. The air and gas are deliverel through the tunnel 4 bypressureA mains 20 and 21. Connections are. made with the mains by pipes leading up through the raises 5 of the new galleries undergoin development, as shown at the extreme right. Regulating valves`22 and 23 are used to adjust the flow of air and gas into the various chambers. I may also use gas burners set intothe chamber walls and connected to the gas and. air pipes 18 and 19.

In order to determine when the distillation is completed in the respective chambers I .provide gas sampling pipes 24 which extend :from tunnel 4 well up into each of the branch raises. The lower end of the sampling pipes 24 extend through thegas-tight bulkhead 16 and are provided at their outer end with suitable valves. To determine the progress of distillation of any chamber, a sample of rthe volatile productsproduced therein is drawn through the gas sampling pipe and analyzed for the percentage of oil vapors, carbon dioxide, oxygen, etc., contained. The amountrof one or more of the above `ingredients will indicate to an experienced operator the progress of the distillation or gasification and the adjustments, if any, that should be' made. vThe gas-tight bulkhead 16 is satis- A.Iliactorily made of angle iron posts covered with .metal `lath and plastered over with cement mortar. When a new set of eight chambers are ready for operating a newbulkhead is erected to correspond as to location with the one herein illustrated, following which the present one is removed. This can be done by use. of a cable connection operated from the other side of the new bulkhead.

Figs. 6 and 7 are similarto the` Vertical section and pian illustrated in Figs. 1 and 2. However, instead of using vertical cham bers and branch raises, I show a modified method of development in which large parallel tunnels 25 filled with large lumps of broken shale are used. As described above, in relation to the vertical chamber method, it is necessary to remove approximately 25 to 35 per cent of the shale from the distilling tunnels in order to provide the voldage in the mass of brokenshale that fills the tunnels. The removed shale will, as above described, be treated in the underground shafts 7 shown in Fig. 7. A method is provided for supplying the heat to the distilling shale by burning air and gas which are supplied through pipes 26 and 27 passing along the service tunnel 4. The gases and vapors evolved in the chambers are removed by gas outlet tunnel 28. This tunnel will likewise serve both as a transportation and later as a gas outlet tunnel. The tunnel 4 will permanently serve as a service and haulage tunnel. Tunnel 4 branches off from tunnel 4 and leads to the vertical distilling shafts 7 in which the mined shale is distilled.

Figs. 8 and 9 are vertical sections lengthwise and across the shale distillingvtunnels shown in Figs. 6 and 7. ike numbers refer to like parts. These tunnels as used to economically treat the thick oil shale beds 1n Utah and Colorado may be approximately 2O to 40 feet wide by 50 feet high and one hundred or more feet long. The oil shale is prepared for distilling by first driving a long development tunnel the full length of the distillingntunnel and having a cross section of proper size to provide the voidage .between the blocks of oil shale that will fill the distilling tunnel when the treatment is under way; this should be approximately 25 to T' 35 percent of the cross section of the distilling tunnel.

The driving of the development tunnel is best shown in Fig. 10 and will be by the usual up-to-date tunnelling methods wherein power loading machines will be used to remove the broken shale andcare will be eX- ercised to save powder and produce the minimum of fines. away and dumped through the gas-tight doors into the distilling shafts 7 where it is treated by passing hot combustion gases from burning gas down through the charge.

Next holes 31 are drilled into the roof of the development tunnel' and of such depth and spacing that when the powder charges The broken shale is trammed 'are fired the roof shale will be broken down in large blocks 29 with the minimum production of fine material. Following this another round of holes are drilled and fired,

each round bringing the pile of broken shale nearer to the roof due to the increase in volume of the brokenshale. The space between the broken material and the roof, just before the last round is fired, should be small enough so that the broken shale after the last round is fired will remain touching the roof. This procedure prevents the formation of a channel over the charge by which route the hot distilling gases could pass instead of through the charge. With blocks of shale averaging 2 to'3 feet in minimum diameter, the time required4 to distill the lumps will be possibly one hundred or more hours. The time required to complete the distillation from`end to end of the tunnel will depend on its length, but for tunnels of 100 feet .in length the time shouldlbe approximately one week. s

This method of development has the disadvantage over the vertical chamber method described above in that the shale removed must be loaded by hand labor or power shovels into cars for haulage to the distilling shafts. However, the chambers are much larger and the shale can be broken down into larger blocks by caving at very low cost, also the amount of-auxiliary development'work is somewhat less.

In Figs. 8, 9 and 10, numeral 4 is the` service and haulage drift. 26 and 27 are respectively the air and fuel gas supply mains with branches and valves leading through portals 30 into the distillation tunnels. 28 is the gas and vapor outlet tunnel and 29 'the blocks of shale forming the pervious charge. 31 are carefully spaced drill holes in the shale roof.

After the blast-ing operations are completed and the tunnel is fullof blocks of shale, the gas and air pipes are run a short distance into the tunnels and the portals 30 sealed with masonry or concrete to form a gas-tight closure. The closure should be reinforced slightly by cross rails or posts so as to provide the necessary strength to resist explosions within the distilling tunnels.

By my method of underground treatment of oil shales or coals I may make further use of the chambers shown in Figs. l to 5 inclusive, to treat further quantitiesof lump carbonaceous materials. The material may be derived from other strata at higher elevations and charged into the chambers by chutes after removal of the spent charge. Also I do not limit myself to the method shown in Fig. 5 for delivering fuel gas and air into the top of the chambers 5, but may prefer to drive service tunnels above the chambers and introduce the gas and air by pipes leadingv through the tunnel.

I claim:

1. The method of obtaining oils and gases from carbonaceous material comprising driving passageways in the material in its natural position, depositing the carbonaceous material removed from the passageways Within other passageways, made in the deposit wherein the shale is not sufficiently rich for independent working thereof, subjecting the material removed in the formation of the passageW-ays to the action of heat at a carbonizable temperature to drive out the volatiles therefrom, subjecting the walls of the passageways to the action of heat at a carbonizable temperature to drive out the volatiles, and effecting a collection of gases and liquid products from the volatiles derived from the Walls and from the removed material.

2. The method of obtaining oils and gases from carbonaceous material comprising dr/iving passageways in the material in its natural position and removing the material dislodged, enlarging the passageways by dislodging carbonaceous material from the walls thereof and thereby e'ecting the formation of loose bodies of material filling the passageways, subjecting the Walls of the passageways and the material therein to the action of heat at a carbonizable temperature to drive out the volatiles, placing the removed material, other deposits containing shale insuiiiciently rich for independent work thereof and subjecting it to the action of heat at a carbonizable temperature, and effecting a collection of gases and liquid products from the volatiles.

3. The method of obtaining oils and gases from carbonaceous material comprising driving passageways in the material in its natural position, driving a shaft in the earth below the passageways, depositing the removed material from the passageways in the shaft, enlarging the passageways by dislodging carbonaceous material from the walls thereof and thereby eli'ecting the formation of loose bodies of material in the passageways, subjecting the walls of the p-assageways and the material therein to the action of heat at a carbonizable temperature to drive out the volatiles, subjecting the material in the shaft to the action of heat at a carbonizable temperature to drive out the volatiles, and effecting a collection of gases and liquid products from the volatiles.

SAMUEL N. KARRICK.

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