Unconventional Reservoirs Core Laboratories Enhanced Oil Recovery Unconventional Reservoirs

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

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

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 2008. 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.

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

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

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

Enhanced Oil Recovery Introduction Core Laboratories Enhanced Oil Recovery Introduction

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

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

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

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

Why investigate Gas Injection EOR?

EOG Update Feb. 2017

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

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 167200 Hydrocarbon Mobilization Mechanisms from Upper, Middle and Lower Bakken Reservoir rocks Exposed to CO2 Hawthorne et al 2013

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

Enhanced Oil Recovery Project Scope Core Laboratories Enhanced Oil Recovery Project Scope

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 169022-MS Experimental Investigation of Enhanced Oil Recovery in Unconventional Liquid Reservoirs; Tovar et al 2014

Produced Liquid Hydrocarbons 6 Gas Cycles

Initial & Residual Hydrocarbon Compositions

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

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