CO2 EOR, Reservoir Sweep and CO2 Storage

Transcription

1 The Wyoming Enhanced Oil Recovery Institute s 2008 Wyoming EOR/IOR Conference CO2 EOR, Reservoir Sweep and CO2 Storage Steve Melzer

2 2 CO 2 EOR, Reservoir Sweep and CO 2 Storage Background and Growth of CO 2 EOR The Concept of and Experience with Reservoir Sweep Incidental Storage of CO 2 in EOR The Converging Worlds of CO 2 EOR and CO 2 Storage

3 BACKGROUND (OF CO 2 EOR PROJECT GROWTH*) GROWTH OF PERMIAN BASIN & WORLDWIDE CO2 PROJECTS WW Projects PB Projects NO. OF PROJECTS * Ref: O&GJ Biennial EOR Editions & UTPB YEAR Melzer Consulting - 5/08 * Includes Only CO 2 Miscible Floods

4 ..and Growth Even with Languishing Oil Pricing GROWTH OF PERMIAN BASIN & WORLDWIDE CO2 PROJECTS NO. OF PROJECTS WW Projects PB Projects Average Growth > 2 Projects/Yr YEAR Melzer Consulting - 8/04 WTI Posted Oil Prices OIL PRICES IN $/bbl $40 $30 $20 $10 $ Average Price = $18.80 (U.S.) YEAR

5 BACKGROUND (OF CO 2 EOR PRODUCTION GROWTH*) 5 WW & PERMIAN BASIN CO2 EOR PRODUCTION Permian Basin Worldwide 300 CO2 EOR PRODUCTION - kbopd * Ref: O&GJ Biennial EOR Editions & UTPB Pt Id t Alli YEAR * Includes both CO 2 Miscible & Immiscible Floods Melzer Consulting - 5/08

6 HOW BIG IS THE CO 2 EOR BUSINESS? Annual Production Rev Figures** U.S. $8.0 billion* PB $5.3 billion* $80/bbl NOV 2005 * Source: Oil & Gas Journal (Mar 08) and CO 2 Flooding Conference (2007) 6 ** Does not take into account the NGLs produced from the recycle volumes

7 ENHANCED OIL RECOVERY AND CO 2 EOR

8 8 BEYOND PRIMARY (AND WATERFLOODS) IMPROVE SWEEP INFILL DRILLING PATTERN MODIFICATION AUGMENTED WATERFLOODING (POLYMER, ETC) LOW SALINITY WATERFLOODING REDUCE WATERFLOOD RESIDUAL THERMAL (CYCLIC STEAM, STEAM DRIVE, SAGD, FIRE) CHEMICAL (ALKALINE/POLYMER/SURFACTANT) MISCIBLE GAS INJECTION HYDROCARBON MISCIBLE FLOODING (HCMF) NITROGEN CO 2

9 EOR METHODS 9

10 10 TODAY S VIEW THE PRODUCING LIFE OF A RESERVOIR IN-FILL DRILLING * Average for San Andres Dolomites (PB)

11 The Concept of and Experience with Reservoir Sweep

12 WATERFLOODING & SWEEP EFFICIENCY 12

13 SWEEP EFFICIENCY 13 WF Swept Area

14 14 WATERFLOOD RECOVERY R = Es * (S Oi S ORwf ) / S Oi S Oi = 0.80 S ORwf = 0.35 Es = 0.70 R =.70 * (.80.35) / 0.80 = 0.39 ROIP (SWEPT REGION ) = 0.70 * (0.45) / 0.80 = 0.39 ROIP (UNSWEPT REGION ) = 0.30 * (0.80) / 0.80 = 0.30 ROIP (TOTAL) = 0.69

15 SWEEP EFFICIENCY 15 WF Swept Area CO 2 Swept Area

16 16 CO 2 FLOOD RECOVERY CALCULATIONS MISCIBLE PROJECTS R = E t * (S OS S ORM ) where: R = Recovery Factor S OS = Oil Saturation at Flood Start S ORM = Miscible Residual Oil Saturation E s > E t R = E t * (S ORWF S ORM ) where: S ORWF = Waterflood Residual Oil Saturation

17 17 PRIMARY + WATERFLOOD AND CO 2 SWEEP EFFICIENCY PRIMARY + WATERFLOOD RECOVERY R = E(p+s) * (S Oi S ORwf ) E(p+s) = R / (S Oi S ORwf )

18 18 CO 2 MISCIBLE FLOODING EXPECTED RECOVERY R = E T * (S ORwf -S ORm ) / S Oi S ORwf = 0.38 S Oi = 0.85 S ORm = 0.10 E T = 0.35 R =.35 * (.38.10) / 0.85 = 0.115

19 19 PHASE I RESERVOIR SCREENING RULES OF THUMB: CO 2 MISCIBLE INJECTION PERCENT OF OOIP 8 TO 18 (12) RATIO TERTIARY / (P + S) 20 TO 35 (25) SWEEP EFFICIENCY 25 TO 50 (35) RATIO E t / E(P+S) 50 TO 60 (50)

20 20 RULE OF THUMB EXAMPLES (1) EUR FROM CO 2 INJECTION FIELD A FIELD B S Wi (% PV) S Oi (% PV) S ORwf (% PV) (P+S) Target (% PV) (P+S) (% OOIP) (P+S) (% PV) E(P+S), %

21 RULE OF THUMB EXAMPLES (2) EUR FROM CO 2 INJECTION 21 FIELD A FIELD B S Oi (% PV) S ORwf (% PV) S ORm (% PV) Tertiary Target (% PV) Tertiary, % OOIP Tertiary, (% PV) E T E T / E(P+S), %

22 RULE OF THUMB EXAMPLE (3) EUR FROM CO 2 INJECTION 22 TERTIARY SUMMARY FIELD A FIELD B %OOIP (S ORwf ) E T T / (P+S) E T / E(p+s), % Tertiary, % OOIP

23 23 PRIMARY, WF AND TERTIARY RECOVERY FROM THE W. TX SAN ANDRES EXPERIENCE WITH A RANGE OF VALUES OF 8-18% BUT BEWARE OF AVERAGES!!

24 24 CO 2 FLOODING: MISCIBILITY FIRST CONTACT DYNAMIC OR MULTIPLE CONTACT RESIDUAL OIL FOR CO 2 FLOODING IMMISCIBLE CHARACTERISTICS OF CO 2 WHY CO 2? OIL RECOVERY FROM CO 2 INJECTION

25 25 DEFINITIONS OF MISCIBILITY Two fluids are "first-contact miscible" if they form only one phase when mixed in any proportions. A process that relies on "Developed" or "Multiple-Contact" miscibility is based on the transfer of components between phases to generate mixtures that avoid the two-phase region. Such processes really involve chromatographic separations of components as phases with different compositions flowing at different rates. Displacement processes may be described as: Vaporizing Gas Drives Condensing Gas Drives Condensing/Vaporizing Gas Drives

26 MISCIBILITY CONCEPTS 26

27 CORRELATIONS FOR MINIMUM MISCIBILITY PRESSURE CO 2 AND CRUDE OIL MIXTURES (Selected References) 1. Holm, L.W. and Josendal, V.A. (1974), Mechanisms of Oil Displacement by Carbon Dioxide, JPT (Dec 74), pp Holm, L.W. and Josendal, V.A. (1982), Effect of Oil Composition on Miscible Oil Displacement by Carbon Dioxide, SPEJ (Feb. 1982), pp Yellig, W.F. and Metcalf, R.S. (1980), Determination and Prediction of CO 2 Minimum Miscibility Pressures, JPT (Jan 1980), pp Johnson, J.P. and Pollin, J.S. (1981), Measurement and Correlation of CO 2 Miscibility Pressures, SPE paper 9790 presented at the SPE/DOE Enhanced Oil Recovery Symposium, Tulsa, April 5-8, Alston, R.B., Kokolis, G.P., and James, C.F. (1985), CO 2 Minimum Miscibility Pressure: A Correlation for Impure CO 2 Streams and Live Oil Systems, SPEJ (April 1985), pp Sebastian, H.M., Wenger, R.S., and Renner, T.A.(1985), Correlation of Minimum Miscibility Pressure for Impure CO 2 Streams, JPT (Nov. 1985). Pp

28 28 WHY CO 2? MISCIBLE AT LOWER PRESSURES THAN NITROGEN OR METHANE CHEAPER AND MORE PLENTIFUL THAN LPG/ENRICHED HYDROCARBON GAS DENSITY (IN DENSE PHASE) CLOSER TO RESERVOIR FLUIDS OIL/WATER

29 29 KEY (MINIMUM) REQUIREMENTS FOR CO 2 MISCIBLE PROJECTS RESERVOIR CHARACTERISTICS CARBONATES / SANDSTONES GRAVITY SEGREGATION STRATIFICATION/FRACTURES CONTINUITY WELL SPACING POROSITY / PERMEABILITY RESERVOIR THROUGHPUT (INJECTIVITY) WATERFLOOD PERFORMANCE

30 IDEALIZED FLOODING

31 31 Fluid Mobility Issues Can Reduce Recoveries And Increase CO 2 Recycling Areal Breakthrough High Mobility Ratio Displacement Initial Radial Flow at Injector, Mobile Oil Bank Develops Preferential Flow Paths Encountered, Recovery Diminished OPTIONS: WAG Injection Design Thickening Agents Selective Injection Profile Modification Cement Liners Re: T. Bradley, EOR CM Workshop, Dec 2006

32 32 HETEROGENEITY* IN A VERTICAL SENSE * Re: T. Bradley, EOR CM Workshop, Dec 2006

33 HETEROGENEITY IN A HORIZONTAL (AREAL) SENSE 33

34 34

35 Fractured Reservoir Model 35

36 36 Naturally Fractured Reservoirs Can Prove Difficult for Flooding (i.e., short-circuiting injector-producer pairs) Can be Useful to establish line drive pattern flooding if unidirectional

37 Naturally Fractured Reservoirs 37

38 38 Increased Sweep Efficiency from Line Drive Patterns 5-SPOTS LINE DRIVE

39 Atypical CO 2 Flooding

40 40 IMMISCIBLE CO 2 FLOODING CO 2 Solubility and Oil Swelling Oil Volume Increase (can be ~50%) Oil From Dead End Pores Incremental Oil Below MMP Viscosity Reduction (Over that of Water) Better Injection Rates Reduces Mobility Ratio Improves Relative Permeability Improves Sweep Efficiency

41 41 CO 2 SECONDARY FLOODING Poor Waterflood Performance (e.g., Clay Swelling) Stratification / Continuity Poor Water Injectivity High Connate Water Viscous Oil Attic Drive RULES OF THUMB NOT WELL ESTABLISHED

42 Residual Oil Zones aka Transition Zones 42

43 Hess Seminole Field Gaines County, West Texas

44

45 45 BALANCING THE PATTERNS With CO 2, substantial oil can be trapped because the producing well may become uneconomic before the oil bank from the other injectors arrives. Pattern balancing is difficult and conflicts with other stated goals such as maximizing injection. In a waterflood, we were able to live with more unbalanced patterns because of the favorable mobility ratio and the relatively low cost of the water. Of course, practical compromises must be made.

46 BALANCED INJECTION THE INACHIEVABLE IDEAL (5-SPOT EXAMPLE) 46

47 PATTERN BALANCING REAL EXAMPLE 47

48 MAINTAINING A CONTINUOUS OPTIMIZATION PROGRAM 48 Regardless of the detail or the quality of the predeployment study and the thoroughness of the plan of operation, performance will indicate changes that will be needed. Opportunities may range from the small and simple to major breakthroughs as the result of new learnings and new technology. Many companies feel the plan is fixed and never have learned this lesson

49 49 MONITORING PROGRAM GOES HAND-IN-HAND WITH THE OPERATING PLAN Strong communication between field and office Pattern injectors and producers in same pay DA! But.. Metering and documentation system for injected and produced fluids Periodic pressure measurements (falloffs and buildups) Initial and (possibly) followup step-rate tests Fluid level program for pumping wells Water quality monitoring Periodic profile measurements Pattern balancing program Program to monitor and adjust WAG ratio and WAG cycles

50 50 TOOLS (1) GRAPHICAL e.g., DIMENSIONLESS PLOTS CAN ID PROBLEM PATTERNS

51 TOOLS (2) 51

52 52 TOOLS (3) SIMULATORS SOME COMMERCIAL SOME PROPRIETARY IN-HOUSE

53 CO 2 FLOODING RECAP (1) 53 PROVEN TO BE TECHNICALLY VIABLE IN MISCIBLE AND IMMISCIBLE RESERVOIR CONDITIONS MOST PROVEN OF THE PROCESSES FOR LIGHT OILS LOW RELATIVE COST OF CO 2 (EXCLUDING TRANSPORTATION - MORE ON THIS LATER)

54 CO 2 FLOODING RECAP (2) 54 REDUCES REMAINING OIL IN PLACE VERY EFFECTIVELY BUT SWEEPS SMALLER VOLUME DUE TO GAS-LIKE VISCOSITY A POOR WATERFLOOD (POOR SWEEP EFFICIENCY) WILL MAKE A POOR CO 2 FLOOD IF PROLIFERATION OF CO 2 SOURCES ARE COMING AND REMOVE (TO A DEGREE) THE OBSTACLES OF DEVELOPMENT OF A PIPELINE NETWORK, THIS WILL COMMERCIALIZE THE: DEVELOPMENT OF LESS EFFICIENT FLOODS IMPLEMENTATION OF SLOWER RESPONDING FLOODS

55 KEY REFERENCES 55

56 The CO 2 Conference Week of Dec 8 th 2008 with Houston and Midland Venues

57 Key Reference Work (1) The Annual CO 2 Flooding Conference 57 Held Each December in Midland, Texas Home to 53 Active CO 2 Floods Concentrates on Actual Case Histories Includes a CO 2 Flood Field Visit Includes a CO 2 Shortcourse Includes an EOR Carbon Management Workshop Great Networking Opportunity Visit: or call

58 58 Key Reference Work (2) THE CO2 FLOODING CONFERENCE SHORTCOURSES 1. Making Money on CO2 Flooding...Some Innovative Development Concepts for Independents..., May Is My Field a Candidate for CO2 Flooding?, September Equipping and Day-to-Day Operations of a CO2 Flood, December How CO2 Flood Surveillance Helps Assure a Successful EOR Program, May a. CO2 Flood Surveillance and Monitoring, December How to Put Together a CO2 Flood, December CO2 Measurements and Metering, December CO2 Facilities and Plants, December CO2 Flooding: Sandstones vs. Carbonate Reservoirs, December Issues for Beginning CO2 Flooders, December Reservoir Modeling and Simulation for CO2 Flooding, December Wellbore Management in CO2 Floods, December Carbon Dioxide Health And Safety, December CO 2 Sourcing for Enhanced Oil Recovery, Dec 2006 ( or phone

59 59 Key Reference Work (3) Practical Aspects of CO2 Flooding, Society of Petroleum Engineers Monograph Volume 22, 2002 ( ssed=spe&prodcdpassed=spe%2dprod%2dmono022)

60 Thank you Questions?