1. Unconventional Reservoirs
Core Laboratories
Enhanced Oil Recovery
Unconventional Reservoirs

2. Eagleford Production Profile
Steep liquids production decline curve recognized
Recovery factors estimated to be 4-6% OOIP
Run a new pipeline
66.9 MBBL Oil & 64 mmcf Gas

3. Duvernay Production Profile
Steep liquids production decline curve recognized
Recovery factors estimated to be 12-14% OOIP
128 MBBL Oil & 440 mmcf Gas

4. Woodford Production Profile Gas Condensate
53,250 BO and 1.2 BCF Gas Produced
The Jean Lafitte 1-28 was completed in October 2007 and was used for the monitor well for the Jean Lafitte 2-28H completed in December The Davy Jones 2-21H was complete in August 2010 and had no noticeable impact on the production of the Jean Lafitte 2-28H. In March 2011, the Stede Bonnet XS 1R-29H was completed and knocked the well off line. Water production increased dramatically and the gas and oil rates are slowly recovering.

5. Where did my Condensate Production Go?
Production efficiency is a key concern in Oil Production
1,408,000 barrels of reservoir oil had to be degassed to produce the 1.13 BCF produced by the well
The 53,250 BO produced represents a 3.8 % recovery factor
A current drained area of 18 acres is calculated
Offset Well Production Characteristics

6. Why investigate EOR in Unconventionals?
Relatively low capital and operating costs
Higher production rates
Increased reservoir recoveries

7. What Does Unconventional Look Like?
MONTNEY - Siltstone
DUVERNAY - Mudstone
WILRICH - Sandstone

8. Enhanced Oil Recovery Introduction
Core Laboratories
Enhanced Oil Recovery
Introduction

9. Traditional EOR Techniques
Gas Injection
Natural gas, CO2, and N2
60% of EOR production in the US
Miscible Flooding most popular
Thermal Injection
Cyclic steam injection
Steam flooding
Solvent steam

10. Traditional EOR Techniques
Fire Flooding
Works best with high oil saturation and porosity
Combustion generates heat and continuous high oxygen content maintains the fire front toward production wells
Chemical Injection (ASP)
Dilute solutions that aid in the reduction of surface tension and capillary pressure (surfactants)
Polymer Flooding
Long chain polymer molecules increase the water viscosity and areal sweep efficiency

11. Approach to Implementation
EOR Screening
Reservoir Data
Laboratory testing (Rocks and Fluids)
Modeling and Simulation
Pilot Project(s)
Pilot programs provide relevant field data that transition EOR projects from models and simulations to sanctioned, full-field implementations.
Pilot Design
Monitoring EOR
EOR Data Analysis

12. Why investigate Gas Injection EOR?
Relatively low capital and operating costs
Higher production rates
Increased reservoir recoveries

13. Why investigate Gas Injection EOR?

14. EOG Update Feb. 2017

15. Favorable Conditions - Gas Cycling EOR
Right geologic properties – good vertical seal
Abundance of gas
Undersaturated oil systems (Pres greater Psat)
Gas condensate – high liquids content
Gas Injection - Miscible Gas Displacement
Right geologic properties
Abundance of the miscible gas
Oil systems

16. Proposed Mechanism for Oil Recovery
Unconventional Reservoir
FRACTURE
Unconventional Reservoir
CYCLE GAS
Unconventional Reservoir
CYCLE GAS
Cycle Gas Diffusion
Vaporization
Unconventional Reservoir
CYCLE GAS
Miscible Dispersion
Unconventional Reservoir
CYCLE GAS
Swelling Oil
Local Pressure Increase
Oil Movement
Unconventional Reservoir
FRACTURE PRESSURE DECREASE
Swelling Oil
Local Pressure Increase
Oil Movement
Unconventional Reservoir
OIL FLOW
Swelling Oil
Local Pressure Increase
Diffusion of cycle gas into matrix
Vaporization of light and intermediate components
Condensation of cycle gas into oil lowering viscosity and swelling oil volume
Pressure gradient formed by swelling oil
Depressurization of fracture establishes flow from matrix aided by pressure gradient from swelling oil
SPE Hydrocarbon Mobilization Mechanisms from Upper, Middle and Lower Bakken Reservoir rocks Exposed to CO2 Hawthorne et al 2013

17. Some Factors Affecting Viability
Reservoir Pressure and Temperature
Fluid properties
Rock Quality
Fracture system (hydraulic and natural)
Depletion rate/Cycle time
Cost of surface injection equipment
Cost of modification of surface processing equipment
Cost of gas
Cost of treatment chemicals

18. Enhanced Oil Recovery Project Scope
Core Laboratories
Enhanced Oil Recovery
Project Scope

19. Reservoir Performance Gas Cycling Method
Increase gas contact surface area circumferentially with proppant and axially with Berea end pieces
High permeability media saturated with cycle gas at appropriate injection conditions
Pressure maintained for appropriate soak period during “injection” cycle
Pressure reduced to expected well drawdown pressure “Production” cycle
Effluent gas produced through cryogenic trap to condense hydrocarbons
Effluent fluids analyzed for composition
Re-pressurize and deplete for subsequent cycles
Experiment modified to simulate appropriate “Gas Cycling” process
SPE MS Experimental Investigation of Enhanced Oil Recovery in Unconventional Liquid Reservoirs; Tovar et al 2014

20. Produced Liquid Hydrocarbons 6 Gas Cycles

21. Initial & Residual Hydrocarbon Compositions

22. Have you included EOR potential in your evaluation of your assets?
Questions?
Have you included EOR potential in your evaluation of your assets?

23. Core Laboratories