1. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Vincent DOÇZY and Hyun YOON Petroleum Engineering — Texas A&M University College Station, TX 77843-3116 (USA) +1.979.255.8808 — vincent.doczy@pe.tamu.edu Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs Orientation Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA

2. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Orientation: The Current Situation ● Known Issues: ■ Production of low-viscosity liquids (including condensates) from tight reservoirs (such as shales) is severely restricted. ■ Less than 5% recovery common(why, how can we improve?) ● The Problem: Wide Range of Strategies ■ Physical Displacement(...is it possible/is it economic?) ■ Viscosity Reduction(... popular concept, but limited?) ■ Production Optimization(... most potential, most complicated) ● Confounding Factors: ■ Top-Down (based on production)(... limits experimentation) ■ Possible Theoretical Model Flaws (... what are we describing?) ■ Evaluation Relies on Innovation(… rather that Inspiring it)

3. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Bazan L., Lattibeaudiere M. et al. 2012. Hydraulic Fracture Design and Well Production Results in the Eagle Ford Shale: One Operator's Perspective. American Unconventional Resources Conference, 5 -7 June 2012, Pittsburgh, Pennsylvania SPE-155779. Work Flow: Development an Optimized Strategy Key Factors: ● Continuous improvement of completion and stimulation design. ● Optimization of critical factors related to the stimulated region. ● Reservoir/fluid properties paired with stimulation parameters (in simulation model). ● Must be able to quantify situation before the optimization. Optimization: ● Integration is the key. ● Data-driven. ● Discrete modeling for point of interest. Example data/technology integration workflow (After Bazan 2012)

4. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA Vincent DOÇZY and Hyun YOON Petroleum Engineering — Texas A&M University College Station, TX 77843-3116 (USA) +1.979.255.8808 — vincent.doczy@pe.tamu.edu Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs Mechanistic Evaluation: Overview

5. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Mechanistic Evaluation: Common Properties Properties Common to Shales: ● Ultra-low permeability. ● High organic content (2.91-11.47 wt%). ● High viscosity liquids reduce mobility. ● Adsorption driven process(s). Jarvie, D. M. et al. 2007. Unconventional shale-gas systems: The Mississippian Barnett Shale of north- central Texas as one model for thermogenic shale- gas assessment. AAPG Bulletin, V. 91, No. 4 (April), P. 475-499. http://dx.doi.org/10.1306/12190606068http://dx.doi.org/10.1306/12190606068 Fig. 1—Histogram and Fingerprint of Barnett Shale (After Jarvie2007). Fig. 2—Hydrocarbon generation potential versus organic content (After Jarvie2007).

6. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Mechanistic Evaluation: Porosity Focus on Porosity: ● Multiphase fluids produce reduced porosity. ● Desorption can increase relative value. ● Overall dynamic property. Robertson, E. P. and Christiansen, R.L. 2006. A Permeability Model for Coal and Other Fractured, Sorptive-Elastic Media. SPE Eastern Regional Meeting, 11-13 October Canton, Ohio, USA. SPE 104380. Key Factors: ● Reservoir Compaction. ● Rate of diffusion. ● Sorption of Gas. ● Particle radius. Fig. 1—Sensitivity of the model to changes in porosity (After Robertson 2006). Fig. 2—Effect of tight matrix porosity on mean field approximation of free gas concentration and its derivative (After Fathi 2009).

7. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Mechanistic Evaluation: Adsorption Adsorption: ● Reversible process ● Controls overall liquid mobility ● Strongly influenced by diffusion flow regime Fathi, E. and Akkutlu, I.Y. 2009. Matrix Heterogeneity Effects on Gas Transport and Adsorption in coalbed and Shale Gas Reservoirs. Transp Porous Med, (80): 281-304. SPE-15227-PA. Key Factors: ● Fluid/Matrix composition ● Adsorption/Desorption kinetics ● Diffusive transport Fig. 1—Macro-kinetic/transport effects on ultimate recovery (After Fathi 2009). Fig. 2—Schematic of desorption area expansion (After Bingxiang et al 2013).

8. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Slide — 8/ xxx Aguilar, A. and McCain, W. D. 2002. An Efficient Tuning Strategy to Calibrate Cubic EOS For Compositional Simulation. SPE Annual Technical Conference and Exhibition, 29 September-2 October 2002, San Antonio, Texas SPE-77382. Mechanistic Evaluation: Phase Behavior Phase Behavior: Past Issues ● Volatile oils and gas condensates cannot be properly described by classical material balance. ● Cubic equations of state produce questionable results for volatile oils and gas condensates. Key Factors: ● Reliable, repeatable, simulation driven. ● Phase behavior description from discovery-level data. Fig. 1— Plot of calculated critical properties C 7+ (After Aguilar 2002)). Fig. 2— Two-phase compressibility factor (After Aguilar 2002).

9. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Pore Proximity Effects: ● Phase behavior ● Gas condensate adsorption ● Inter-phase interaction Devegowda, D. and Sapmanee K. et al. 2012. Phase Behavior of Gas Condensates in Shales Due to Pore Proximity Effects. SPE Annual Technical Conference and Exhibition, 8 -10 October 2012, San Antonio, Texas SPE-160099. Mechanistic Evaluation: Phase Behavior Past Issues: ● Conventional simulation tools and models ignore (often severe) inter-phase interactions. ● No known approaches available to implement this effect. ● Could this effect lead to enhanced production (i.e., reduction of condensate blocking or drop around the well)? Key Factors: ● Nano-science: effects of confinement on critical pressure and critical temperature. ● New effective phase diagram needed. ● Definitely implies enhanced adsorption effect. Fig. 1— Gas viscosity of heavy gas-condensate mixture using modified Pederson correlation at Tr = 400 ⁰ F (After Devegowda 2012).

10. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Capillary Pressure: ● Capillary pressure effect used to integrate permeability model with phase behavior. ● Used modified Brooks and Corey model. ● Modeled as curvature change. Nojabaei B. and Johns R.T. 2012. Effect of Capillary Pressure on Fluid Density and Phase Behavior in Tight Rocks and Shales. SPE Annual Technical Conference and Exhibition, 8 -10 October 2012, San Antonio, Texas SPE-159258. Mechanistic Evaluation: Capillary Pressure Effects Past Issues: ● Capillary pressure not considered significant factor (equilibrium calculations). Key Factors: ● Influences phase behavior, saturation, and Langmuir volumetric strain constant. ● Bubblepoint pressure lowered due to increased interfacial tension. ● Related to high flowing bottomhole pressures. Fig. 1— Phase diagrams of various mixtures of C 1 –C 6 (After Nojabaei 2012).

11. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Vincent DOÇZY and Hyun YOON Petroleum Engineering — Texas A&M University College Station, TX 77843-3116 (USA) +1.979.255.8808 — vincent.doczy@pe.tamu.edu Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs Work In Progress Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA

12. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Work in progress: Theoretical Model: Mass Balance Statistical Rate Theory: ● Raoult's law-level mass transport description ● Allows arbitrary level of precision ● Removes the necessity for fitting parameters. Kapoor, A. and Elliott, J. 2010. Statistical Rate Theory Insight into Evaporation and Condensation in Multicomponent Systems. J. Phys. Chem B, (114):15052-15056. http://dx.doi.org./10.1021/jp106715vhttp://dx.doi.org./10.1021/jp106715v Past Issues: ● Transport across the interface determined by empirically derived mass transfer coefficients. ● Multicomponent evaporation/ condensation processes unmanageable. Key Factors: ● Descriptions of flow mechanisms. ● More effective phase diagram. Fig. 1— Effects of competitive evaporation due to initial concentration (1 = water, 2 = ethanol) (After Kapoor 2010).

13. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Background: The Eagle Ford shale play has had significant growth since 2009, with strong well performance especially in the condensate window. Fan L., Martin R. et al. 2011. An integrated Approach for Understanding Oil and Gas Reserves Potential in Eagle Ford Shale Formation. Canadian Unconventional Resources Conference, 15-17 November 2011, Calgary, Alberta, Canada SPE-148751 Work in progress: Case Study — The Eagle Ford Key Factors: ● Uniqueness due to in-situ reservoir fluids ranging from black oil to dry gas. ● The liquid-rich areas requiring higher fracture conductivity as a result of multiphase flow and higher viscosity fluids. ● Can we infer critical factors for liquid production? ● What are the pertinent parameters for liquid flow rate enhancement? Fig. 1—The Average oil production bubble map (larger bubbles indicate higher rates) (After Fan 2011).

14. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Vincent DOÇZY and Hyun YOON Petroleum Engineering — Texas A&M University College Station, TX 77843-3116 (USA) +1.979.255.8808 — vincent.doczy@pe.tamu.edu Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs Summary Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA

15. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Summary: ● Conventional Reservoir Models ■ Based on large/ coarse scale considerations. ■ Flow mechanisms adapted from analogs. ■ Calculations limited by computational power. ● Mechanistic Reservoir Evaluation ■ Diagnostic understanding of fluid/matrix behavior. ■ Application of fine-scale descriptive equations (flow/PVT/etc.) ■ Simulation used to assist decisions rather than descriptions. ● Future work: ■ Proper foundation will facilitate applicable results. ■ Limitations to data extrapolation still as of yet unclear. ■ Clear trends may prove elusive due to "noise reduction" considerations. This needs help, I don't know what it means…

16. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Vincent DOÇZY and Hyun YOON Petroleum Engineering — Texas A&M University College Station, TX 77843-3116 (USA) +1.979.255.8808 — vincent.doczy@pe.tamu.edu Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs End of Presentation Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA

17. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA Student Biographies: — Vincent DOÇZY — Hyun YOON

18. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Brief Biography: Doçzy ● Role: — Crisman Graduate Assistant Research (GAR), Texas A&M U. — B.S. Physics (w/ Chemistry/Math) Indiana University — M.S Candidate Texas A&M U. (PETE) — Sergeant U.S. Marine Corps ● Recognition: — Member Physics honor society ∑π∑ (2012) — SMART Grant Research Fellow (2011) — Governor Frank O'Bannon Scholar (2009) — MFRI Grant Recipient (2012) ● Current Research Activities: (?) — Nano-Scale Flow Phenomena — Reservoir Engineering of Near-Critical, "Liquids-Rich" Shale Systems — Evaluation of for Shale/Liquids-Rich Systems — Numerical Modeling of Ultra-Low Permeability Reservoir Systems

19. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Brief Biography: Yoon ● Role: — Crisman Graduate Assistant Research (GAR), Texas A&M U. — Ph.D. Student, TAMU — M.S. Energy System Eng., Seoul National University — B.S. Civil, Urban, Geosystem Eng., SNU — B.S. Business Administration (Dual Degree), SNU ● Research & Work Experience : — Reservoir Characterization Study of Oil Sand (2011) — Inflow Performance Analysis of Subsea Reservoir (2011) — Development of Modeling Technology for CTD Operation (2010) — Fixed Income Sales & Trading Associate, Samsung Securities — Sergeant, Korean Augmentation to the U.S. Army ● Current Research Activities: — Liquids-Rich Unconventional Reservoir Engineering — Multiphase Flow Modeling near Stimulated Reservoir Volume — Reservoir Simulation for Liquids-Rich Shale Reservoirs

20. 2013 Crisman Institute Meetings | 01 May 2013 Texas A&M | College Station, TX, United States Evaluation of EOR of Low-Viscosity Liquids from Tight/Shale Reservoirs V.M. Doçzy and H. Yoon | Texas A&M University Vincent DOÇZY and Hyun YOON Petroleum Engineering — Texas A&M University College Station, TX 77843-3116 (USA) +1.979.255.8808 — vincent.doczy@pe.tamu.edu Evaluation of Strategies for Enhancing Production of Low-Viscosity Liquids from Tight/Shale Reservoirs End of Presentation Presentation for Crisman Institute Meetings 01 May 2013 — College Station, TX, USA