Executive Summary

Behrooz Fattahi, Aera Energy LLC
Alan Johnson, Shell EP Solutions UK

Executive Editors of  SPE Reservoir Evaluation & Engineering alternate writing the Executive Summary. This issue's summary is by Behrooz Fattahi.


This is my first column as the co-Executive Editor of SPEREE. It is my pleasure to be involved with the peer-review process and to be associated with the distinguished team of volunteer editors and the fine SPE staff who collectively make this process a success.

You all know that the peer-review process is perhaps the most important function of SPE, placed at the heart of its mission of dissemination of knowledge. Realizing the importance of this process burdens us with the great responsibility of preserving the high quality of the published papers as well as the timely delivery of reviews to expedite the transfer of ideas and knowledge from inception to application. Our process statistics show that in the past few years, we have improved the review-cycle time. However, we still can go a long way in this direction without having to sacrifice the quality of the journal, and that we must. My goal in the next 2 years will be to accomplish this.

Last November, I asked each of the 120 Technical Editors of the Reservoir Engineering portion of this journal to formally commit themselves to review three to five papers in 2007; 75 of the editors responded positively to my call. Since then, I have increased the number of Review Chairs and at the same time reduced the number of Technical Editors in each review team to eight members. This change should allow Review Chairs to carry a lighter load while increasing their focus on the quality of approved papers and the timely delivery of their decisions.

The editors in the peer-review process have determined that they can afford allocating some of their time and effort to this critical SPE function. With this clear commitment from the team, I intend to use this energy to improve the process. In the meantime, I need your help in building up the number of volunteer editors. I am looking for more qualified people who can commit to reviewing three to five papers in 2007. Other activities are also underway to optimize the process of peer review, and I will report on these in due course.

This issue of the journal brings you 10 excellent papers:

  • The first paper, by Gozalpour, Danesh, Todd, and Tohidi, presents the results of an investigation of the impact of oil-based mud-filtrate contamination on various types of reservoir-fluid samples. The authors propose a tracer-based technique to determine the original composition of reservoir fluids from contaminated samples.
  • The second paper, by Stalder, presents the results of a numerical-simulation study of Cross SAGD on mobilizing bitumen and achieving a significant rate and thermal-efficiency advantage over the conventional SAGD method, particularly at lower reservoir pressures. The author also discusses the disadvantages of Cross SAGD application in narrow sand-channel developments as well as potential operational challenges.
  • In the third paper, Gates et al. use numerical-simulation modeling in search of a SAGD strategy to maximize steam/oil ratio in reservoirs with top gas. They propose high initial chamber injection rates prior to the chamber’s contact with the gas cap, reducing it only after breakthrough to minimize convective heat losses.
  • The fourth paper, by Osterloh and Menard, offer a methodology to overcome the challenges involved in decision making for optimized expansion of heavy-oil fields. This approach uses two spreadsheet simulation-based tools that facilitate populating the model with many horizontal wells, followed by performance forecasting for a given scenario. This rapid screening methodology was developed for a depletion-drive production mechanism in heavy-oil fields, but it has not been tested for other reservoirs or production mechanisms.
  • The fifth paper of this issue is authored by Spivey, Valko, and McCain; it presents a correlation for accurate estimation of the isothermal oil-compressibility coefficient for use in material-balance applications. The authors use more than 3,500 lines of data from 369 laboratory studies to develop this correlation equation, which calculates the average compressibility between the bubblepoint pressure and a higher pressure of interest.
  • In the sixth paper, Shaoul, Behr, and Mtchedlishvili describe the development and capability of a tool to interface a hydraulic-fracture model and a 3D reservoir simulator. This is an improvement over past attempts to model post-hydraulic fracture behavior by modifying skin or productivity index in a simulator.
  • The seventh paper, by Hiraiwa and Suzuki, presents a new method to incorporate residual oil saturation to gasflood into a compositional reservoir-simulation model. This new method prevents the simulation models from incorrectly predicting lower-than-prescribed residual oil saturations, a phenomenon caused by vaporization of oil components allowed by the equation of state.
  • The subject of the eighth paper, by Mohannadi, Ozkan, and Kazemi, is a discussion of pressure-transient responses of horizontal wells in anticlinal structures as well as curved and undulating wells in slab reservoirs. The authors show that in the absence of a gas cap, conventional horizontal-well models can be used to approximate the flow characteristics of the systems in which the well trajectory does not conform to the curvature of the structure.
  • The subject of the ninth paper, by Yamada and Okano, evolves around the modeling and history matching of a complex pressure system usually occurring in stacked rhyolite lava domes erupted in a submarine environment. An approach using a combination of multipoint geostatistics and probability perturbation is shown to successfully capture the curved facies boundaries within stacked lava domes while accounting for pressure information by means of history matching.
  • The tenth and final paper of this issue, by Egermann, Laroche, Manceau, Delamaide, and Bourbiaux, describes the details of an experimental and numerical study of water/gas imbibition in vuggy carbonates. This is important to tight gas carbonate reservoirs that face early water breakthrough because of the presence of fractures and an active aquifer. This study provides a representative experimental data set and an enhanced understanding of the physical processes governing such imbibitions.