Meeting Examines History-Matching Advances, Future Challenges

History-Matching may have made significant advances during the past 10 years, but the lack of industry standards and other challenges could prevent the discipline from being universally accepted. A recent Applied Technology Workshop titled “History Matching: New Developments and Best Practices” identified the current benefits of and future needs for the technique that matches geological models to field production data, with the ultimate goal of predicting future reservoir output.

The meeting’s 90 attendees represented a cross section of engineers, geoscientists, and academicians. This diverse group not only had different levels of experience in implementing history matching but also employed many different approaches, which they shared freely. “In general, there was a broad consensus that there is no single best approach to history matching and no uniform approach across the industry,” said Akhil Datta-Gupta, who holds the LeSuer Chair of Petroleum Engineering at Texas A&M U. and was Chairperson of the workshop. Many attendees agreed that the approach taken is often tied to the process and the decisions to be made. “It is important to identify model objectives at the outset and define the attributes of a good history match,” Datta-Gupta said. “In general, a structured approach to history matching allows us to easily reproduce the results and transfer the technology to younger engineers.”

What Is Best, What Is Missing

The five major topics discussed at the Houston-based event were Work-flow and Best Practices, Field Applications and Case Studies, Assisted History Matching/Inverse Modeling, Uncertainty Assessment, and New Developments. Within each topic discussion, there were the recurring themes of what is best about today’s history-matching technology and what is missing. Mike King, Senior Adviser, Reservoir Modeling and Simulation for BP America Inc., gave the first keynote address, focusing on the extent to which history-matching technology has changed over the past decade. “Ten years ago, SPE held a forum on history matching, and it is interesting to see that some of the techniques addressed then are now reaching a level of maturity where we can apply them,” he said.

A decade ago, many geologists and engineers held a negative view of the technology because they thought it was taking reservoir analysis out of their hands. “Over the past decade, our understanding of what the technology can do has matured to the point where people can characterize a reservoir’s performance in ways that were impossible just 10 years prior,” King said.

Datta-Gupta said the advancements over the past 10 years have taken various forms, and have included

Integrated-workflow tools.
Software for handling and assessing multiple models and simulations.
New history-matching algorithms.
The use of streamline-based approaches and experimental design/response surfaces.

The breadth of techniques being employed by various companies was interesting, and perhaps somewhat unexpected. “I was surprised to see the great variety of approaches, some of which are much more practical than they were 5 or 6 years ago. This variety really struck the audience,” said A. Stan Cullick, Senior Research Fellow at Landmark Graphics Corp. Perhaps the greatest boon to the more widespread use of history matching has been the increase in computational power. “Many of the recent advances could never have happened without the availability of large-scale computing,” said Cullick, who presented his research on identifying uncertainties in history-matching data and modeling and how these enter the workflow.

While history matching has certainly advanced, there was little doubt among those in attendance that much is missing. Among some of the challenges still facing the technique are

How to integrate data at different scales and disciplines.
How to incorporate new data types such as those from temperature sensors.
Addressing fundamental physics related to asphaltene and geomechanics.
Tools for dynamic gridding and data filtering.

Datta-Gupta summarized some of the other major needs addressed by attendees. “The majority of the participants felt that it is important to examine multiple scenarios, multiple models, and multiple forecasts, keeping the key business decisions in mind and making managers understand the need for multiple matches,” he said. “It was felt that there should be ‘collocated’ teams of engineers and geoscientists and multiple iterations between them during the history-matching process. This is comparatively easier to accomplish today because of availability of software and increased computational power.”

Another recurring theme was the need for developing an industry-standard data set that can be used to evaluate different techniques. Many in attendance agreed that SPE could facilitate this initiative. Said King: “SPE can move history matching toward maturity by helping the industry develop test data sets from real reservoirs that are accessible to everyone. We are really looking for much richer sets of data than what is currently available so that we can start developing some standards on what does and does not work.”

While there are many tasks to be completed before some of the new developments in history matching are fully embraced by the industry at large, the attendees agreed that history matching will continue to play an important role in reservoir management and defining field-development strategies. “There have been significant new developments in the assisted- and automatic-history-matching techniques in the past decade, and the industry needs to take advantage of these developments,” Datta-Gupta said.

Workshop Looks at Unlocking Potential of Heavy Oil

Heavy oil is a petroleum resource too big to ignore, but if it is to become commercially viable, more cooperation and understanding are needed between engineers, from the reservoir to the refinery. This cooperation and dialogue took a major step forward at a first-of-its-kind joint workshop between SPE and the American Inst. of Chemical Engineers (AIChE) titled “Unlocking the Challenge of Heavy Oil.”

The 2-day workshop, held recently in Galveston, Texas, brought together more than 100 engineers and field professionals from upstream and downstream in an attempt to solve the challenges of producing and processing heavy oil. “We looked at the task of unlocking heavy oil as making the individual challenges fit together like the pieces of a puzzle,” said workshop Chairperson James Langer, Principal Technical Expert for Shell Global Solutions. “It is the role of SPE and AIChE to put the puzzle pieces together. The interest in economically developing heavy oil for large-scale production and processing is not surprising if one considers that worldwide energy demand continues to increase, while production of more conventional, lighter crudes is decreasing. Add to that the estimate that heavy oil accounts for 60 to 75% of all known reserves, and it is clear heavy oil will have to be a major contributor to the energy mix in the future.”

Teaching the Basics

Attendees examined an array of current technologies and technological challenges affecting the upstream, midstream, and downstream during eight sessions. The upstream sector kicked things off with sessions that addressed characterization of heavy crudes and how their properties influence equipment design and field-development planning, both onshore and offshore. Upstream engineers also introduced their downstream counterparts to the challenges and techniques employed in processing and transporting heavy oil in the field, with emphasis on crude upgrading and water-assisted flow of heavy oil in pipelines.

The refiners then took over with a series of presentations on downstream processing, including a discussion of the challenges of refining heavy crude. These back-to-basics presentations gave attendees a chance to understand how a process undertaken at one stage could affect other stages, either upstream or downstream. “I definitely saw certain parts of the downstream process where I realized what we were doing (upstream) was having a direct impact on the refinery,” Langer said.

Other sessions were devoted to presenting the latest research and technologies being deployed in processing heavy crudes in the field, such as advances in electrostatic precipitation, inline subsea processing, and the use of disk-stack centrifugation. Downstream research presentations highlighted the latest on predicting the tendency for fouling or coking in upgraded crudes.

The need for the workshop became clear as discussions continued among the international audience, Langer said. “It became clear that we were all facing the same problems. There wasn’t one issue brought up where someone said, ‘Oh, we solved that 10 years ago.’ Each issue discussed was one where there were not a lot of viable solutions yet,” he said. “This first workshop proved that it’s good to have SPE and AIChE working together on any and all energy production challenges. We never know where the next big breakthrough will come from.”