Executive Summary

Behrooz Fattahi, Aera Energy
Alan Johnson, Shell UK

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

In this editorial, I thought I might discuss the subject of interdisciplinary integration and, among other things, how it impacts the review process.

As you may be aware, on the Reservoir Evaluation side of SPEREE, we have separate review groups managed by individual Review Chairs who cover a number of specialist areas: geophysics, reservoir geology, petrophysics, core analysis, well testing and analysis, and general reservoir engineering. The papers that we review and publish generally fall under one or another of these broad headings.

What I have noticed over recent months is a trend of increasing numbers of integrated papers coming through, which cross a number of these different specialist areas, such as the integration of geophysical information into a geological model and its onward impact on dynamic modeling.

While, as I will discuss later, I personally feel that this is a marvelous development, it does present a challenge to our functionally defined review system. For me, I have the question as to which team I assign the paper for review. Each of our predefined groups of specialists can address only a subset of the subjects covered by such a paper. In practice, I have found that most Review Chairs are able, when they plan the review of such a paper, to solicit input from other specialists outside their own immediate team. This is typically what is happening, but it does represent something of a change to our way of working on the review team.

My personal enthusiasm for papers and presentations dealing with cross-discipline integration stems from my conviction that it is only by working in this way that we can really come to fully understand our reservoirs. The true value of, for example, a detailed piece of core work only becomes apparent when one understands its impact on our understanding of the reservoir as a whole.

While we have not seen many of these papers published in the journal so far, there are a significant number currently in the review process. If you are the author of such a paper awaiting revision, let me encourage you to submit your revised manuscript as soon as possible so that it can be considered for publication. I do see this as a significant area of evolution in the type of information we present in our journal.

In our day-to-day work, this integration has been potentially facilitated with the advent of geocellular models. These permit the integration and visualization of structural, geological, and well data on a full-field level leading up to their integration into the full-field dynamic simulation model. This development holds the promise of true reservoir integration, by means of what some have called the “Shared Earth Model.” This also marks a potential move away from the more traditional discipline silos in which the geophysicist generated his top reservoir map, the petrophysicist generated his formation properties at the wells, and they passed these on to the development geologist, who generated a static model that was then passed to the reservoir engineer for dynamic simulation. In this traditional workflow, it was difficult to incorporate many meaningful feedback loops—the key to better understanding.

The fact that we are seeing an upsurge of integrated multidiscipline papers is an indication that the long sought-after integration is now really happening in numerous teams; however, it is not yet universal. From my own experience in working for a number of operating companies and locations, I have come across a number of potential “integration blockers” that still may need to be tackled.

• Geographic—The different members of the team may not be co-located, but spread around different sites, or even different countries. They also may be separated in time, with different vintages of work being integrated into the final result while the respective authors have moved on elsewhere.

• Organizational—Individuals are only assigned or contracted to a particular project to complete their part of the jigsaw puzzle without being expected to contribute to the integrated whole.

• Individual personalities—This, I think, is the most interesting and potentially the hardest barrier to break down. I would like to elaborate a little more on this below.

We should recognize that there is a significant comfort factor derived from staying within one’s own technical discipline, where everyone talks the same language. Take, for example, the recent debate in the SPE Formation Evaluation discussion forum on total vs. effective porosity. One thing that becomes clear from such discussions is that these terms can mean quite different things to different groups: petrophysicists, geologists, and reservoir engineers. It is almost as if we speak different languages. These barriers must be overcome before we can even start on integration.

Another blocker is that some people fundamentally prefer to work on their own, to the point of avoiding integration. This can lead to some interesting exchanges:

“Go away, this is my shared earth model.”

“These are my results, I’m an expert, so what do you mean by ‘uncertainties’?”

“I know if I asked three of you guys, you would come up with three different answers, so I chose not to use your input; I made up my own numbers.”

These may not all be actual quotes, but more a distillation of comments I have heard over the years. Nevertheless, they do capture a flavor of the mental models that still must be challenged on our road to a better view of the reservoirs we seek to understand.

As I said, I hope we will be able to bring you a number of these integrated papers over the coming months. In the meantime, I hope you will enjoy the papers in this current edition as yet further pieces to add to our jigsaw puzzle of true reservoir understanding.