Executive Summary

Diederik van Batenburg, Shell

This issue of SPE Res Eval & Eng brings you nine papers that reflect areas of current activity and areas of interest in the industry. Two papers focus on carbon capture and storage. Three papers cover different aspects of enhanced-oil-recovery processes. There are two papers that present improved reservoir characterization and simulation methods to cover multiscale data and processes. The final two papers provide models to evaluate, predict, and improve the understanding of production from shale-gas wells.

Carbon Capture and Storage

Approximate Analytical Solutions for CO2 Injectivity Into Saline Formations provides analytical models to predict bottomhole pressure in vertical CO2-injection wells. The models include multiphase-flow and phase-transition effects. It is demonstrated that the models provide reliable injectivity estimates.

Real-Time Evaluation of Carbon Dioxide Production and Sequestration in a Gas Field presents a case history on CO2 separation from a produced gas stream and subsequent disposal of the CO2 in a saline aquifer. The workflow to understand the producing behavior of the gas field, the storage capacity of the saline, and its interdependencies is described.

Enhanced Oil Recovery

Pore-Scale Evaluation of Polymers Displacing Viscous Oil--Computational-Fluid-Dynamics Simulation of Micromodel Experiments demonstrates how the processes that manifest themselves at large scale. An increase oil production caused by improved vertical and areal sweep originate from processes occurring at the microscale where polymer is diverted into less favorable flow paths because of the shear thinning properties of the polymer solutions.

Modeling Steam-Assisted Gravity Drainage With a Black-Oil Proxy presents a creative solution to use black-oil models as proxy for full thermal models in evaluating SAGD sensitivities and optimizations in order to reduce the computational requirements.

Improved Predictability of In-Situ-Combustion Enhanced Oil Recovery provides a multistage combined experimental and modeling workflow to arrive at successful predictions of in-situ combustion performance at the field scale. Additional details on the individual steps of the workflow have been presented in earlier papers, of which some have appeared in SPE Journal.

Reservoir Characterization and Simulation

Improving Reservoir Characterization and Simulation With Near-Wellbore Modeling illustrates a workflow that allows for the inclusion of seismic and wireline data, image logs, and core data into a high resolution near-wellbore model that subsequently can be upscaled for inclusion in a field-scale model.

Capturing the Effect of Fracture Heterogeneity on Multiphase Flow During Fluid Injectionprovides guidelines and demonstrates how to upscale heterogeneous fracture models effectively for fractured carbonate reservoirs while maintaining the ability to capture the heterogeneous flow behavior.

Shale Gas

On the Liquid-Flow Analog To Evaluate Gas Wells Producing in Shales presents solutions to the equations that can be used to predict the performance of horizontal wells completed with multiple infinite-conductivity fracture in shale-gas reservoir.

Pressure-Dependent Natural-Fracture Permeability in Shale and Its Effect on Shale-Gas Well Production challenges the perceived need to pump proppant into the natural fractures in shale-gas reservoirs on the basis of a combined experimental and modeling study.

The papers previously described were all reviewed and ultimately approved in the peer-review process. However, the conclusions presented in these papers are not cast in stone. As sharing of knowledge and experiences is essential, SPE welcomes further "discussion" of any paper published in any SPE journal. Therefore, please feel free to submit a discussion of a paper to SPE if you disagree with interpretations or conclusions presented or if the authors and reviewers have missed publications that either support or invalidate results. I look forward to receiving such discussion letters.

Diederik van Batenburg