Modeling deeper waters

Audrey Leon

June 1, 2015

Audrey Leon spoke with Schlumberger’s Alexander Neber, technical marketing manager, Software Integrated Solutions (SIS), to discuss how software can solve reservoir engineering and other deepwater exploration challenges.

OE: What are the specific deepwater challenges that have to be addressed by a modern software platform?

 Visualize the interplay between regional tectonics, salt morphology, and the overburden to identify potential oil and gas traps. Combine powerful 3D rendering and advanced edge-detection attributes with multi-Z salt interpretation for delineation and characterization diapirs, domes, and other salt structures.
Images from Schlumberger.

Neber: In deepwater, the objective of modern geoscience and engineering solutions is to enable users to maximize prospect knowledge and reduce technical and economic variables. With rising rig costs and ever deeper and more complex drilling targets, operators are driven to achieve short decision and evaluation time. At the same time, they strive to minimize the number of exploration and appraisal wells and to reduce the associated risk and cost, as well as to maximize the value of their acquired data. Economic success of any deepwater exploration campaign is associated with the identification of the right plays and productive prospects, before extensive drilling, to verify and appraise the target closures.

OE: Could you illuminate these deepwater challenges in more detail, for example, for Geophysics workflows?

Neber: Generally speaking, deeper waters are accompanied by deeper prospects, often hidden below complex and seismically opaque geological structures.

Exploration teams must illuminate complex structures in as much detail as possible, often below overlying geology such as carbonate rocks or laminated sands below salt, and basalt formations. Deepwater exploration uses techniques based on acoustic and elastic inversion, rock physics analysis, and property modeling. In addition, pre-drill pore-pressure analysis is key to evaluate pore pressures that might be encountered during drilling.

OE: How does Petrel make deepwater exploration less risky and more cost efficient?

Neber: The Petrel E&P software platform delivers collaborative workflows that unite the subsurface disciplines of geophysics, geology, geological modeling, reservoir engineering and drilling. Its framework makes workflows repeatable to ensure comprehensive uncertainty assessment from seismic to simulation. By enabling disciplines to work together, all team members and their work processes contribute to developing a single volumetric earth model – static and dynamic – scalable for both deepwater exploration and development projects.

Streamlining efforts are further supported by the Studio E&P knowledge environment that enables multi-user collaboration, as well as effective capturing and sharing of knowledge between remote users.

Evaluate uncertainty from play to prospect scale, calculate chance of success and risked volumes, and move prospects through to the exploration drilling program. 

OE: What specific, software-related measurements are required to address reservoir engineering challenges in deepwater?

Neber: The primary goal of deepwater reservoir studies is to answer essential questions concerning structure, reservoir extent, compartmentalization, formation quality, and producibility. Petrophysical and geological measurements can be made while drilling to get an early understanding of the reservoir and to plan further detailed data acquisition and sampling programs.

Deepwater reservoirs are often thinly layered and highly laminated and the assessment of each is critical for decisions on completions.

The analysis of fault distributions based on downhole measurements and 3D seismic fault identification techniques is important.

The Petrel platform unites the subsurface disciplines of geophysics, geology, geological modeling, reservoir engineering and drilling to evaluate structure, reservoir extent, compartmentalization, formation quality and producibility. Earth-model uncertainties are analyzed in the Petrel platform and can be connected to the ECLIPSE industry-reference reservoir simulator and the INTERSECT high-resolution reservoir simulator to perform flow simulations. Optimization and experimental design techniques allow rapid analysis of multiple realizations to evaluate numerous development alternatives to come up with a robust field development plan.

OE: In general, how does software, like Petrel, change the way deepwater exploration is conducted in the oil and gas industry?

Predict lithology and pore fluid content with a complete range of advanced, intuitive, and interactive tools for seismic data conditioning, rock physics, AVO or AVA analysis, prestack and poststack deterministic and stochastic inversion.

Neber: Until now, the majority of industry effort has been spent on defining the trap and reservoir. Also, in the past, the charge and seal analyses have been difficult to use and integrate into a streamlined geoscience workflow, although a significant percentage of exploration failure is related to a lack of understanding of these processes. Today, software platforms like Petrel can address and simulate charge and seal. Petrel incorporates science and workflows from the PetroMod petroleum systems modeling software, and fault seal evaluation software, making them easier to perform on an integrated system. The GeoX exploration risk and resource assessment software has been integrated into Petrel workflows for an easy-to-use and scalable decision-support technology for risk, resource and economic evaluation of exploration projects and portfolios.

OE: As new technologies continue to be developed, how do we see exploration needs changing in the future?

Neber: In the future, the need for technology advances will be greater to meet the challenges of finding the smaller fields, more subtle traps and traps in hard-to explore areas and reducing costs.

A typical question is often simply “How do we start?” followed by “How can an objective and auditable assessment be made, what are the controlling factors, what data is needed and which factors are really important?” As always, the geology is the starting point and resource assessments are only meaningful if they take the petroleum system risk factors that control the development of the resource into account. It is also essential that all of the underlying data can be audited and the entire assessment workflow is reproducible and open for critical reviews.

OE: It must be difficult to train operator staff on all these new technologies for deepwater exploration and keep a high knowledge standard with fast changing software capabilities.

Neber: Yes. Modern training has to go well beyond traditional software classroom training and support help files. For example, technology adoption packages (TAP) combine consulting, targeted training, deepwater workflow optimization and best-practice methodologies designed for specific workflows.

We also have a cloud-hosted workflow centric guidance module — Petrel Guru — embedded in our Petrel platform. It allows a fully interactive automation of common deepwater workflows, making common tasks faster, more approachable and comprehensible.

Dr. Alexander Neber serves as technical marketing manager, Software Integrated Solutions (SIS). He came to Schlumberger in 2007. He worked as a petroleum systems modeling and discipline lead for exploration technology in the Middle East and Asia. After two years as geoscience business manager in Australia, he joined the Schlumberger Software Integrated Solutions HQ team in 2014. He received a diploma in geology from Frankfurt University, Germany, and a PhD in sedimentology from the University of Cologne.