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life) wa+ld bt hijhtt than i.d Scared in FiF. F.'a <br />At Conditions under which the Gquivalcnt nahrnlttc <br />solubility is 1 Ib per pound of water, at a high enough <br />pressurr ra pn-vent decomposition, 1 ton of oil shale <br />eonnining 2S•gaUton and 20-wei=ht-pvecnr tuhcolitc <br />would raquirc <br />(2.000Ib (02 IbN ~. <br />lyr ~ of shale l _ ID oil shale <br />1.0 Ib NaCH _a\ (35D Ib~_l <br />IbHz Jl bblH fJ/ <br />1.14 bblpfwater . ................... (1) <br />eo dissolve all the tuhcoltte. <br />Since, in this cast, 1 ton of oil shale ronuins 25 g^I of <br />Oil. Nt minimum ware rt:quirements for these conditions <br />would be 1.9 bbt of wattt per barrel of oil rssvvered. <br />Solubilitirs highs than 1 Ib of oqurnlcnt naheolite per <br />pound of water would rcduGt this watt Itquirefllenl. <br />whereas in[flreien[ict in oil rteortty or in rnaintaininb a <br />aahcolite•satuntcl effluent stream would inert-ast it. <br />Sclcction of proper citculat;on pancrns and (low rota <br />is important to the df¢icm and speedy removal of the <br />wluble salts, especially during start-up In the absence Of <br />hydraulic fnctuies nr some other means for establishing <br />communication between wells, IcaMing operatwns may <br />be carried out fmm ~ single well. <br />Fig 7 schcmaucally shows weer (lowing downward <br />in the annulus between tub;np .nd the encased ponion of <br />^ wcllborc, both of which ezlcnd below the hose of a <br />Ssahtro{ite-rich Isyer. Because of less mtcrfcrrncc from <br />insoluble materials, the dissolution of the nahrolite layer <br />proceeds at a faster rate thin in the overlying oil•shalc <br />Interval, even though that interval may contain rtahmlite <br />nodules. Relatively fresh water entrrT the top of the <br />ruhcolite•layer interval and (lows along dle top Of the <br />leached cavity. Once it reacho the nahcolnc, the wares <br />dittolves it and becomes denser. Bcuust of gravity <br />forces, tfic denser fluid then (lows to the wellbore along <br />the bottom of the dvity close to the as•yet-undissolved <br />nahcolim The ntr of radial cavity growth a rnntrolled <br />by natunlconvection. Venicaldiffusionbetweenthcaall <br />tolution and the overlying fresher water reduces the <br />buoyancy forces driving the natural conv¢inn and slows <br />the ralt 0(ndral canny gmwsh The rime requited (pr she <br />Irad~ng tdgc of the leaded eavlry to advance 100 to 200 <br />ft fmm the wellbore under reasonable solution-mining <br />conditions is meazurcd in monks In time, the ovttlying <br />Oil Shalt will fncnrre, spell, and/w rubbl c, allowing the <br />)eachmg of m nahcot;te romcnt and af(caing the circula• <br />lion of fluid in the Rlhcolitc rich lays. <br />Althwgh nc~ IuchinEstep do<rribed thus fir involves <br />the use of a single well, simile will units close by mey be <br />ronxcted by dissolution of the nahcolilt-rich layer, i( <br />desired. Once communintion is aublished, pNtt oP- <br />lions arc available for enhancing the growth rate of the <br />dissolves ppR volume, primarily through seleclipn of <br />injenbn and prcxluaun intervals and rata. <br />Conversion Methodti <br />Eis:ntially, any thermal rrrn.cry process uxed in pit <br />rucrvoin an be appliruf to recover shale-nil prp7ucu <br />from the nibbled Drocas tone. pro+ided the tempmture <br />Icvcl w sufficiently hrgh ro p}rolyte the kcrogcn. Thc <br />ta. <br />pymlysis pf kern~tn y'mld xhalc-nil pmducn can 6e <br />eompletal essentially in a few minuns st s temper.turc of <br />900 'F. In-cite eombusion, therefore, has long born <br />popular as a method for obtaining sttolt-oil products.'~° <br />7Tr is process version it illustrated xdrerriatiplly in Fig. B. <br />As illuttrattA, nr is injcned inro the process mnc (which <br />hus been leached and nibbled be(arhand) to burn eokod <br />kcpgrn and pyrolyre the oil shalt ae the wmbustion <br />host moves downward. Low-he~ting•value produq gas <br />may be recycled to the rnjertion point b moderate pe.k <br />itmpeuafures and incttast process control. Hot~gu in)ec- <br />iron at tcmpcraturts of 900 'F and higher also hu been <br />eontidered a rtwvery prottss.tt This rcttien of the <br />soluble-salt process is similar to in•situ wrnbustion in <br />that it requires the development of the process soot <br />6eforc the pyrolyf it atty. In the pyrolysis step, however, <br />Orr iMalr <br />raear, rater <br />ar sn,re <br />Mali wwTN <br />F10. 7-$dl.ernalit nlarasanratm for 4a~lrp a nahsytlle IMtl. <br />'.~•.~~c~.~.' uaerryrta .t~.to ..a avwrec o-. u..re <br />p4. a-SLtlmlata: a.9rs„ 01 Rx mnveraiyr W; wrap <br />wn~atori w tyFyay vyeCm <br />JOURNAL pF -f'1ROLEL'M 7F.C71.rOt.O(iY <br /> <br /> <br />