Petroleum Engineers

46-4 PETROLEUM ENGINEERING HANDBOOKTABLE 46.3-PRODUCTION BY IN-SITU COMBUSTION (1962) for development of thermal recovery methods, since theresults will be most rewarding if a percentage of these-BID %-resources can be tapped economically.U.S.10,228 40.0Based on an assumed oil price of $22.OiVbbl, LewinCalifornia4,873and Assocs. Inc. I6 estimated that the ultimate recoveryIllinois179Kansas2in the U.S. by thermal recovery methods will amount toLouisianaMississippiTexas2,9401,3009345.6 to 7.9 billion bbl. This includes 4.0 to 6.0 billion bblby steamfloods and 1.6 to 1.9 billion bbl by firefloods.Canada5,690 22.1Alberta150Production MechanismsSaskatchewan5,540The production mechanisms in steam in’ection processesBrazil284 1.1have been identified by Willman et al. 14 as (1) hot water-Venezuela2,799 10.8Romania6,699 26.0flood, including viscosity reduction and swelling, (2) gas- ~drive, (3) steam distillation, and (4) solvent extraction ef-Total 25,760 100.0fect. The relative importance of these mechanisms on lightand heavy oil, represented by 37.0 and 12.2 “API, respectively,is given in Table 46.6.TABLE 46.4-MAJOR THERMAL RECOVERY PROJECTSSteamfloodSteamFirefloodThermalstimulationField, Location(Operator)Kern River, CA (Getty)Duri, Indonesia (Caltex)Mount Poso. CA (Shell)San Ardo. CA (Texaco)Tia Juana Este,Venezuela (Maraven)Lagunillas, Venezuela(Maraven)Duri, Indonesia (Caltex)Cold Lake, Alberta (Esso)Suplacu de Barcau,Romania (IFPIIPCCG)Battrum No. 1,Saskatchewan (Mobil)Bellevue, LA (Getty)Jobo. Venezuela(Lagoven)Enhanced OilProductionVW83,00040,00022,80022,50015,00040,85022,00010,0006.5522,9002,72313,000In &floods, the above mechanisms are also important.In addition, the breaking up of heavy oil fractions intolight oil fractions through cracking should have at leasttwo effects: increase in volume and more drastic reductionin viscosity. The gas drive effect also should be increasedbecause of the large amount of air injected andcombustion gas produced.Theoretical ConsiderationsSurface Line and Wellbore Heat LossesIn current field practice, downbole steam generators arestill in the developmental stage. Surface steam generatorsare being used in almost all of the steam injectionprojects. Steam from a generator normally is sent to theinjector wellhead through a surface line. Some heat willbe lost to the surrounding atmosphere by convection andradiation. As steam travels from the wellhead through thewellbore to the sandface at the pay zone, heat will be lostto the overburden, mainly by conduction. The method ofcalculating surface line and wellbore heat losses is discussedbelow.TABLE 46.5-RESERVOIRS AMENABLE TO STEAMFLOODAND FIREFLOODSteamfloodFirefloodDepth, ft160 to 5,000 180 to 11,500Nei pay, ft 10to1,050 4 to 150Dip, degrees 0 to 70 0 to 45Porositv. % 12to39 16to39Permeability, md 70 to 10,000 40 to 10,000011 oravitv, OAPI -21044 9.5 to 40011 iiscosity at initialtemperature, cp4 to 106 0.8 to lo6Oil saturation at start, %15to85 30 to 94OOIP at start, bbl/acre-ft370 to 2,230 430 to 2,550Surface Line Heat LossesThe steam lines in most of the steam injection projectsare insulated. The heat loss from such a line, Btuihr, is:Qr,=2ari,U,;(T, -T,,)AL, (1)where‘in= outside radius of the insulation surface, ft,r, = steam temperature, “F,7’,, = atmospheric temperature, “F, andti = pipe length, ft.In the above, CT,. is the overall heat transfer coefficient(based on inside radius of the pipe or tubing), Btu/hr-ft-“F, and can be calculated as follows.Uti =-11+- h+l ) . . . . . . . . . . .where rro is the outside radius of pipe, ft, and khin is thethermal conductivity of insulation material, Bm/hr-sqR-OF.I