30 th Oil Shale Symposium Colorado School of Mines A LOW CO 2 HYBRID IN-SITU SHALE LIQUID PRODUCTION PROCESS Jacob Bauman, Prashanth Mandalaparty, Pankaj Tiwari and Milind Deo Department of Chemical Engineering, University of Utah, Salt Lake City, UT
20 20 th th O October er 2 2010 OIL SHALE CHALLENGES Ò Oil shale pyrolysis is an energy intensive process. Ò Heating rate is typically slow. Ò Initial permeability is low. Ò Heating requirements, hydrocarbon products, and carbonate decomposition contribute to CO 2 and other emissions.
20 20 th th O October er 2 2010 CONCEPT Step 1:Pyrolysis - Heating wells rapidly heat the formation near the well. Products are generated, including coke. Permeability is increased in “hot” zones according to a model relating fluid porosity and permeability. k mul = 5 in these simulations. Step 2: In-situ combustion - After initial pyrolysis period air is injected into the formation. Coke combustion supplies heat to formation far from heating wells. Step 3: CO 2 injection - CO 2 is injected to drive out remaining oil, and for CO 2 storage
20 20 th th O October er 2 2010 SI SIMULATI TION N 50 ft thickness. 26.5 ft between Injector 1 and Injector 2.
20 20 th th O October er 2 2010 ENERGY S SAVINGS W WITH I IN-SITU C COMBUSTION 112 MBTU savings with in-situ combustion switching at 600 days. 5.00E+08 U) (BTU) Pyrolysis 4.50E+08 followed by y Heaters ( 4.00E+08 combustion 3.50E+08 by H 3.00E+08 Pyrolysis lied b 2.50E+08 only 2.00E+08 y Suppli 1.50E+08 nergy S 1.00E+08 Ene 5.00E+07 0.00E+00 0 500 1000 1500 2000 2500 3000 3500 4000 Time me ( (days ys)
20 20 th th O October er 2 2010 PRODUCTION C COMPAR ARISON 157 bbl more oil is produced when pyrolysis is followed by combustion although products could be consumed during the combustion stage. 500 l) (bbl) 450 l Produced ( Oil Production 400 with combustion 350 300 Oil P 250 Pyrolysis only lative O 200 150 mula Cumu 100 50 0 0 500 1000 1500 2000 2500 3000 3500 4000 Time me ( (days ys)
20 20 th th O October er 2 2010 PRODUCTION COMPARISON Gas production is also significantly improved with combustion period. This is somewhat counterintuitive. 500000 Gas 450000 production 400000 (scf) with 350000 combustion produced ( 300000 250000 Pyrolysis only 200000 Gas p 150000 Ga 100000 50000 0 0 500 1000 1500 2000 2500 3000 3500 4000 Time me ( (days ys)
20 20 th th O October er 2 2010 OBSERVATION Product mobility is an issue in the “cold zone” at the bottom of the resource. This causes oil to pool.
20 20 th th O October er 2 2010 OB OBSER ERVATION ION With higher heating rate 373 bbl oil are produced compared to 280 bbl with lower heating rate. With pyrolysis only there is a tradeoff between recovery and heating requirement. 7.00E+08 Pyrolysis followed by combustion 6.00E+08 U) (BTU) Pyrolysis only y Heaters ( 5.00E+08 Pyrolysis only (higher heating rate) by H 4.00E+08 lied b 3.00E+08 y Suppli nergy S 2.00E+08 Ene 1.00E+08 0.00E+00 0 500 1000 1500 2000 2500 3000 3500 4000 Time me ( (days ys)
20 20 th th O October er 2 2010 CO 2 BALANCE Ò Pyrolysis followed by CO 2 injection É Net CO 2 injected = 8040 ft 3 Ð Most CO 2 injected is produced. Oil pools at the bottom of the resource. Ð No carbonate decomposition reactions included. Ò Pyrolysis followed by In-situ combustion and CO 2 injection É Net CO 2 injected = - 597,000 ft 3 Ð 600,000 ft 3 CO 2 are generated from combustion Ð Only a small fraction of the generated CO 2 is injected.
20 20 th th O October er 2 2010 GEOCHEMICAL STUDY Ø To study the geochemical implications of injecting CO 2 into the spent shale formation Ø Most of the organic content is driven out as oil and gas Ø The subsurface has the geochemical complexity to drive the sequestration reactions Ø Current effort focuses on ü Understanding the fate of CO 2 in the spent shale formation ü Studying the basic reactivity of CO 2 -brine mixtures with rocks in the formation. ü The mineralogical changes in the rock ü The changes in brine chemistry
20 20 th th O October er 2 2010 SPENT S SHAL ALE U USED F FOR G GEOCHEMICAL AL S STUDY • Green River formation – Oil shale u Core sample- ¾ ” diameter ü Pyrolysis (N 2 ) - 60ml/min ü Temperature -350C ü Duration - 24 hrs ü Weight loss 12.61% ü Oil yield 4.84%
20 20 th th O October er 2 2010 SEQUESTRATION EXPERIMENTS Ø High temperature, high pressure experiments Ø 316 stainless steel reactors Ø Feed samples – spent shale Conditions Ø Brine composition: 3-5 weight% Ø Temperature: 200 0 C Ø Feed gas composition: CO 2 Ø Reaction period: 7-35 Days Ø Analysis • Rock Chemistry: XR XRD, (X-ray Diffraction) • SEM, (Scanning Electron Microscope ) SEM • EDS DS, (Energy Dispersive X-ray analysis) • • Brine Chemistry: IC ICP-M -MS, (Inductively coupled plasma-mass spectrography) •
20 20 th th O October er 2 2010 EXPERIMENTAL SETUP SO 2 , N SO , NH 3 3 , H , H 2 S S P as f feed g gases with C h CO 2 2 P N 2 N 2 for leak test P SO 2 , N SO , NH 3 3 , H , H 2 S S as f feed g gases Te Temperature with C h CO 2 2 Cont ntrolle ller Single P Supercritical cylinder CO 2 positive displacement CO 2 pump Pump
20 20 th th O October er 2 2010 INITIAL XRD ANALYSIS Illite 3.8% Dolomite 69% Quartz 8.0% Albite 10.8% Orthoclase 6.4% Analcime 2.1% Interlayered chlorite/smectite (or C/S) also observed, but is below the detection limit (~1*) for the bulk analysis.
20 20 th th O October er 2 2010 METHODOLOGY v The reactors fed with the sample and brine- allowed to equilibrate v CO 2 is fed into the reactors and the reactors are isolated and allowed to cook at temperature v Each reactor is cooled and degassed in time intervals of 7 days to analyze the reaction progress v After the experiment reactor is degassed and products analyzed v The results compared with the initial XRD analyses and the products identified through XRD and SEM analyses v The correlation of the rock chemistry with changes in brine chemistry is identified
20 20 th th O October er 2 2010 PRINCIPAL REACTIONS CO 2 (g) CO 2 (aq) H 2 O + CO 2 H 2 CO 3 H 2 CO 3 H + + HCO 3 - CaCO 3 +H + Ca 2+ + HCO 3 - Ca 2+ + CO 3 2- CaCO 3 2H + + CaAl 2 Si 2 O 8 + H 2 O Ca 2+ + Al 2 Si 2 O 5 (OH) 4 CaAl 2 Si 2 O 8 + H 2 CO 3 + H 2 O CaCO 3 + Al 2 Si 2 O 5 (OH) 4 NaAlSi 3 O 8 + 3 H 2 O NaAlSi 2 O 6 .H 2 O + H 4 SiO 4 2KAlSi 3 O 8 + 9H 2 O + 2H + Al 2 Si 2 O 5 (OH) 4 + 2 K + + 4H 4 SiO 4
20 20 th th O October er 2 2010 RESULTS AFTER 2 WEEKS Omni-present woody fragments
20 20 th th O October er 2 2010 RESULTS AFTER 2 WEEKS Signs ns o of C Ca-z -zeoli lites p precipitation n
20 20 th th O October er 2 2010 RESULTS AFTER 3 WEEKS Hollo llow p prism o m of C Ca-z -zeoli lite growing ng o on w n weathe hering ng ortho hocla lase
20 20 th th O October er 2 2010 RESULTS AFTER 3 WEEKS EDS DS a ana nalys lysis o of C Ca-z -zeoli lite
20 20 th th O October er 2 2010 RESULTS AFTER 3 WEEKS Ano nothe her ho hollo llow Z Zeoli lite c crys ystal l growing ng o on a n a q quartz g grain n
20 20 th th O October er 2 2010 RESULTS AFTER 3 WEEKS Pha hase a alt lteration o n of i illi llite t to c chlo hlorite
20 20 th th O October er 2 2010 RESULTS AFTER 4 WEEKS Di Dissolu lution o n of d dolo lomi mite g grain n
20 20 th th O October er 2 2010 RESULTS AFTER 4 WEEKS Precipitated d dolo lomi mite Etche hed d dolo lomi mite g grain n
20 20 th th O October er 2 2010 RESULTS AFTER 4 WEEKS Dolo Do lomi mite g grain e n etche hed Kaoli lin d n deposition n
20 20 th th O October er 2 2010 RESULTS AFTER 4 WEEKS Kaoli lin d n deposition o n on i n illi llite
20 20 th th O October er 2 2010 RESULTS AFTER 4 WEEKS Etche hed o ortho hocla lase feld ldspar w with t h traces o of dolo lomi mite p precipitates
20 20 th th O October er 2 2010 RESULTS AFTER 5 WEEKS Poorly c ly crys ystalli llized k kaoli lini nite w with s h some me w well c ll crys ystalli llized v veriform k m kaoli lini nite
20 20 th th O October er 2 2010 RESULTS AFTER 5 WEEKS Dolo Do lomi mite g growth i h in i n int nterstitial s l spaces i in q n quartz
20 20 th th O October er 2 2010 BRINE CHEMISTRY Ion Na Mg Al K Ca Fe Ba Si Cl Conc (mg/l) 10675 0.0009 0.10 <0.005 0.8 <6 0.003 <8 19060 • Brine prepared from laboratory grade NaCl • 3 g of brine in 30 cc DI water
20 20 th th O October er 2 2010 BRINE CHEMISTRY 60 180.0 160.0 50 140.0 n mg/l l 40 ntration mg n mg/l l Mg 120.0 ntration mg 30 K 100.0 ncent Al Conc 20 Fe Ca 80.0 ncent Si Si Conc 60.0 10 40.0 0 0 weeks 2 weeks 3 weeks 4 weeks 5 weeks 20.0 Time me 0.0 0 weeks 2 weeks 3 weeks 4 weeks 5 weeks Time me
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