Executive Summary

Diederik van Batenburg, Shell

This is the last column of my 3-year term as Executive Editor of the reservoir engineering section of SPE Res Eval & Eng. Over the last 3 years, I have had the opportunity to evaluate hundreds of manuscripts and reviews of these manuscripts by Associate and Technical Editors in order to make decisions as part of the peer-review process. I would like to thank all Associate and Technical Editors as well as SPE staff for their efforts and dedication; without your support and dedication there wouldn’t be peer-reviewed SPE journals! Authors and readers are the complementary requirements for peer-reviewed journals and are essential to fulfill SPE’s mission to disseminate knowledge. I hope that both authors and readers agree that SPE Res Eval & Eng has continued to provide opportunities to disseminate and dissipate knowledge and that this will continue as I handover to my successor, Gary F. Teletzke.

Gary is senior technical advisor for enhanced oil recovery (EOR) at ExxonMobil Upstream Research Company (URC), where has been employed for more than 30 years. At ExxonMobil URC, he has led research projects related to gas injection EOR, chemical EOR, CO2 sequestration, and compositional reservoir simulation. He has also led several EOR field studies, integrating laboratory work, reservoir simulation, and pilot testing. Teletzke has long been active in SPE, serving as co-chair of the SPE Forum on Offshore EOR in 2008, and as a committee member of various EOR and related committees over the past 2 decades. He was Technical Editor for SPE Res Eval & Eng during 2000–2006 and served as Associate Editor since 2007; he was also named SPE Outstanding Technical Editor in 2007 and several times Outstanding Associate Editor. He has published 34 technical papers and was named an SPE Distinguished Member in 2013. Teletzke holds a BS degree from Northwestern University and a PhD degree from the University of Minnesota, both in chemical engineering.

This issue of SPE Res Eval & Eng brings you 14 papers that reflect areas of current activity and interest in the industry. Two papers focus on seismic applications. Another two papers are related to logging and well testing; two more papers are related to techniques to relate pore-scale properties to reservoir properties. The industry’s continued interest in unconventional reservoirs is reflected in four papers on shalegas evaluation and performance prediction and one paper on recovery of heavy oil. The final two papers deal with reservoir simulation and optimization.

Seismic Applications

Analysis of Oil-Volume Fluxes of Hydrocarbon-Seep Formations on the Green Canyon and Mississippi Canyon: A Study With 3D-Seismic Attributes in Combination With Satellite and Acoustic Data provides an analysis of natural hydrocarbon seeps in the Gulf of Mexico. Hydrocarbon seepage is associated with deep cutting faults, generated by vertical salt movement, that provide conduits for upward migration of oil and gas. More than 24,000 anomalies that might be related hydrocarbon seeps have been identified. The identification of these seeps is relevant because they may be associated with gas hydrates but could also point to potential geohazards for offshore-field developments.

Multiattribute Seismic Analysis With Fractal Dimension and 2D and 3D Continuous Wavelet Transform proposes new multiattribute seismic algorithms by using fractal dimensions and 2D/3D continuous wavelet transforms. The application of these algorithms results in better illumination and proper demarcation of various geological features such as salt domes, channels, and faults.

Logging and Well Testing

Extreme High-Pressure and/or High-Temperature Wireline-Data Acquisition: Planning for Success intends to provide an overview of what is involved in the planning, preparation, and execution of extreme high-pressure and/or high-temperature (30,000 psi or 2,068 bar and 500°F or 260°C) wireline-data acquisition from the customer setting the information objectives through to data delivery.

Accurate Measurements of Liquid-Condensate Rate With Multiphase-Metering Technology Improve Ecological Impact of Well Test in Deepwater Well Offshore Brazil presents a case history that compares liquid condensate rates obtained from conventional separators with a multiphase flowmeter during well tests offshore Brazil and explains the differences observed. 

Multiwell Deconvolution develops and extends single-well deconvolution to the larger and more-complex multiwell deconvolution problem. The proposed algorithm is applied to a synthetic example with known solution and an uncertainty analysis is performed to quantify the impact of nonuniqueness on multiwell deconvolution. The use of the algorithm is illustrated further with a field example.

Reservoir Properties From Pore-Scale Measurements

Modification of the Kozeny-Carman Equation To Quantify Formation Damage by Fines in Clean, Unconsolidated Porous Media illustrates how incorporating the volume of fines and a dimensionless bulk factor into the Kozeny-Carman equation can be used to model how the quantity and structure of deposited fines control permeability.

Effects of Segmentation and Skeletonization Algorithms on Pore Networks and Predicted Multiphase-Transport Properties of Reservoir-Rock Samples compares the results of three different segmentation algorithms. The algorithms are applied to microcomputed-tomography (CT) images to obtain estimated porosity, amount of clay, and clay distribution. The segmentation results are subsequently used to predict multiphase transport prop-erties and are compared with measured capillary pressure and relative permeability curves.

Shale Gas

Well Recovery, Drainage Area, and Future Drill-Well Inventory: Empirical Study of the Barnett Shale Gas Play presents an empirical study based on the history of more than 16,000 drilled wells and calibrated density log porosity and net-pay-zone-thickness maps. The intent is to estimate the remaining technically recoverable free gas, predict individual well recoveries and areas drained by those wells, and the future drill-well and refracturing inventories.

Imbibition and Water Blockage In Unconventional Reservoirs: Well-Management Implications During Flowback and

Early Production presents multiphase flow simulation results with newly collected stress-dependent relative permeability and capillary pressure data that provide an explanation for the field experience that longer shut-ins after a hydraulic fracture treatment result improved productivity while reducing water production.

Combining Geostatistics With Bayesian Updating To Continually Optimize Drilling Strategy in Shale-Gas Plays introduces a methodology to evaluate subsurface uncertainty during the development of shale-gas plays where, even after many wells have been drilled, the performance of new wells remains highly unpredictable. The methodology considers the “chance of success” (CoS) to be an uncertain variable. An initial probability distribution of the CoS is derived from information of analogous plays combined with local information. Because each new well is drilled, the outcome is used to update the previous probability distribution. Application of the methodology is illustrated with a well set from the Barnett shale.

Gas-Production-Data Analysis of Variable-Pressure-Drawdown/Variable-Rate Systems: A Density-Based Approach demonstrates that production-data analysis of variable-bottomhole-flowing pressure/variable-rate gas wells under boundary-dominated flow is possible by the use of a density-based approach. The paper provides a rigorous derivation of the approach and presents example cases that illustrate the applicability of the approach.

Heavy Oil

Optimal Application Conditions of Solvent Injection Into Oil Sands To Minimize the Effect of Asphaltene Deposition: An Experimental Investigation provides results of low carbon number n-alkane and a distillate hydrocarbon injection in glassbead- packs saturated with heavy oil at pressure and temperature conditions typical for Canadian oil-sand reservoirs.

Reservoir Simulation and Applications

Optimization of Uncertain Structural Parameters With Production and Observation Well Data provides a case history in which optimization approaches on the basis of response surfaces and the ensemble Kalman filter were used to reduce the uncertainty in fault offset and reservoir volume while maintaining the fault properties similar to base-case assumptions.

A Semi-Implicit Approach for Integrated Reservoir and Surface-Network Simulation presents a “semi-implicit” method for coupling subsurface reservoir models to surface network models. The authors claim that the semi-implicit coupling overcomes the problems found in explicit coupling without requiring the complexity of fully coupled models.

The above papers were all reviewed and ultimately approved in the peer-review process. However, the conclusions presented in these papers are not cast in stone. Because the sharing of knowledge and experiences is essential, SPE welcomes further “discussion” of any paper published in any SPE journal. Therefore, I again urge you to submit a discussion of a paper to SPE if you have alternative views on methods, interpretations, and/or conclusions presented or if the authors and reviewers have missed publications that either support or invalidate results.