Deep-water reservoirs are more important than ever as we gain more understanding of how complex systems have resulted in prolific reservoirs that possess often surprising volumes of oil and gas that are very long-lived, due in part to the existence of compartments often with high permeability and porosity.
Welcome to an interview with Dr. Jon Rotzien, Founder & President of Basin Dynamics in Houston, TX. Dr. Rotzien is teaching his highly-acclaimed power-course in Deep-Water Systems / Siliciclastics at OTC on Saturday, April 29.
Susan's Note: Deep-water reservoirs are elephants in our industry, and now, thanks to new technology and analytics, the elephants are hiding in plain sight, just waiting for your team to find them and to welcome them home.
Hello, Dr. Rotzien. Tell us a little about yourself and your connection to the oil and gas industry.
Like many of us in AAPG attending OTC, everything I do is about the rocks and the petroleum they hold. I've enjoyed working as a petroleum geoscientist after completing an industry-sponsored PhD program. Houston is home. It's been a joy to be part of the industry community here. I started Basin Dynamics just over a year ago. My focus is developing consulting relationships and professional training courses in oil and gas industry centers. My field courses to major deep-water outcrop belts in California, Ireland, France, and New Zealand utilize modern and proprietary research. Recently, my deep-water petroleum reservoir training courses have been in North America. Later in 2017, Basin Dynamics will be conducting courses in Europe and Asia. Basin Dynamics courses focus on all scales of deep-water reservoirs, from pore-scale to seismic-scale, and from new ventures to development. I'm delighted and honored to teach my 1-day short course in Houston for OTC. It's inspiring to have thousands of industry professionals from all around the world come together in Houston. It's one of my favorite times of the year.
Why are deep-water siliciclastic petroleum reservoirs important to understand in today's E&P environment?
It's important to characterize petroleum reservoirs to make informed business decisions at every stage in the value chain. Typical challenges in frontier basins involve understanding the presence and quality of reservoir. In appraisal and development, companies want to quantify the uncertainty in reservoir connectivity and the likelihoods of bed lengths, shale drape, and lateral variation in depositional environment and reservoir quality. These data are used for static and dynamic reservoir modeling. The science of deep-water reservoirs is so closely tied to the economics of the project.
What are the most important aspects of deep-water depositional systems, from an industry perspective? Why do we focus our attention on deep-water systems?
When oil price is relatively low, it's essential to understand the risks and associated uncertainties pertaining to reservoir presence, reservoir quality, and seal presence. These are three of the main risks in any conventional drilling program. With a clear understanding of these risks, exploration success will increase. If all of the risks work, then it's onto appraisal in most cases. Basin Dynamics expertise is the half of the risk formula primarily dealing with the reservoir and seal. But there is the other half of the risk process that demands skills in petroleum systems and structural geology. It's always good to keep your structural and petroleum systems friends close! Exploration requires teamwork.
As an industry, the focus is on deep-water reservoirs because they comprise many fields around the world today. When the economics of onshore and offshore field development are compared, often they are not so different. Another important point is that deep-water reservoirs also occur on modern day continents. Some of the formations in the Delaware and Midland basins were originally deposited well below wave base and consist of hemipelagic drapes, turbidites, debrites, and transitional flow deposits. These form similar types of petroleum reservoirs observed well below mudline in bathyal settings today in the Gulf of Mexico.
What aspects of deep-water reservoirs are sometimes overlooked? How can we better understand compartmentalization?
Consider these factors. The scale, range of variability, and heterogeneity in deep-water depositional systems and their petroleum reservoirs need to be evaluated. Oftentimes companies are interested in what is a reasonable interpretation of a submarine fan's net:gross, size, and internal architecture. In the not-so-distant past, submarine fan models were quite simple, and yet they represented novel research into deep-water environments. Today, our understanding of deep-water processes and their effects on sediment transport and deposition has advanced, yet we as a scientific and industry community have directly observed just a handful of deep-water sediment gravity events. To put that in perspective, we could go out right now and study thousands of fluvial systems. Those datasets just aren't publicly available for deep-water systems yet.
There are a number of modern methods being applied to petroleum reservoirs to understand compartmentalization and inform well planning decisions. Some of those include major, trace and REE geochemical techniques, detrital zircon U-Pb ages, new seismic processing methods and attribute analysis, as well as outcrop analogue datasets.
Building on the topic of compartmentalization, what makes deep-water reservoirs highly connected? How is the geology connected to the economics of the play?
That's a great question. I've heard the saying, "All models are wrong, some are useful." There are models of deep-water environments ranging from submarine valleys, to aprons, and even stepped, perched and ponded depositional systems on continental slopes. Each of these models carries implications for reservoir connectivity, yet it is important to understand a dataset from a first principles perspective. What is the shape of the basin, and how was it formed? How energetic were the flows? What is the grain size, and the fractions of clay and silt? What are the lithofacies and higher orders of architecture? In this way, a predictive model can be built that does not solely rely on rote application of generalized models from other systems that may be useful as analogues, but may not provide the answer to a unique depositional system and play fairway.
Where are some of the most exciting plays today? And in the future?
If we knew that, Dr. Nash, we'd start our own E&P company! Perhaps the most exciting turbidite plays are happening in western Texas, Alaska, northern and southern portions of the Atlantic, SE Asia, Gulf of Mexico, and Caribbean. There are lots of opportunities to get involved if you have passion, persistence, and dedication. Earth still holds secrets, and we just have to continue to search for them.
In my most recent course at AAPG ACE, we had participants from over a dozen countries. These professionals have worked all over the world. They bring with them diverse experiences from many different types of petroleum basins and deep-water reservoirs. Collaborative course exercises enrich and enhance the course experience as well as promote the discovery of more of Earth's secrets.
For more information, please visit my website at www.basindynamics.com.
Jon Rotzien, Ph.D