When it comes to improving the efficiency and accuracy of subsurface modelling, Shell changed the game with GeoSigns. The system has already played a key part in the development of major fields in areas such as the Gulf of Mexico, and it has the potential to make more complex and challenging fields viable. Jim Banks speaks to Shell’s Bettina Bachmann about the history – and the future – of GeoSigns.

In making decisions about where to drill to find the next big oil and gas fields, the energy majors have vast amounts of data at their disposal. While it is always part of the plan to bring in more data sources, the biggest challenge is modelling the existing data in an efficient and effective way to discover the next viable reserve.

As the reservoirs being investigated become increasingly complex and harder to reach, the industry relies ever more heavily on the accuracy of its modelling systems and the ability of operators to easily interpret the data they have. GeoSigns, which is Shell’s high-end platform for geological and reservoir modelling, provides enhanced evaluation and visualisation capabilities that allow geoscience and petroleum engineering experts to greatly improve the planning and management of oil and gas extraction.

This powerful subsurface interpretation software brings together vast amounts of seismic and non-seismic data, and allows engineers to interpret that data in a far more integrated and collaborative way than was previously possible.

It has already helped Shell to locate hydrocarbon deposits faster and more cost-efficiently. In some instances, it has brought to light significant finds in areas that were thought to be dry.

A case in point is the discovery of over 150 million barrels of oil beneath subsurface salt structures in the Deimos field in the Gulf of Mexico. GeoSigns enabled Shell’s engineers to take the first look under these complex salt structures, and the rest is history. Similarly, GeoSigns played a big part in Shell’s tapping of reservoirs off the coast of Brazil.

These impressive results are the fruit of a long and expensive process of research and development.

"We had the original thought for GeoSigns around eight years ago, and we had an application called 123DI looking at seismic information. The challenge was to interpret and visualise data in 3D on a single screen, and we needed a more modern interpretation tool that could bring together seismic data, gravity data and magnetics in an integrated way," says Bettina Bachmann, VP subsurface and wells software at Shell.

"There was a very strong pull from end users for more integration and a new visualisation technology. What we have now is an integrated system comprising three proprietary technologies. We can bring in all kinds of data, including the thermal history of a basin. "So, we are going beyond simple interpretation."

A geophysicist by training, Bachmann spent 22 years in the operational side of the business, working on exploration and field development, before moving into technology and strategic planning roles. Now, she oversees all software deployment in engineering and exploration, looking after off-the-shelf and proprietary systems. The majority of the software is developed in house, with teams in 25 locations to deploy and support technologies such as GeoSigns

"There was also a push from the research team to develop ways of visualising data, and improve business modelling by linking IT and domain expertise. There has been a big change in technological capability and a step up in the quality of data we need. Three decades ago, we would see simple basins that were well understood, and those datasets look the same with modern systems. But the things we are chasing now are deeper, sometimes below layers of salt, and are much more complex. We are developing very different types of reservoir now," she explains.

The 123DI system was achieved through Shell’s concerted efforts to develop advanced proprietary systems, and its preference for in-house technology development persists. If 123DI was effective at bringing R&D and engineering capability closer in order to shorten the development cycle, GeoSigns takes that one step further.

"The 123DI system was achieved through Shell’s concerted efforts to develop advanced proprietary systems, and its preference for in-house technology development persists."

GeoSigns supports the accurate subsurface modelling by interpreting a wider variety of data types to enable simpler and quicker assessment of whether the extraction of reserves is economically viable. 3D visualisation makes the data analysis comprehensible to a wider audience within the business, and 4D visualisation software captures the movement of resources through the reservoir over time.

The system incorporates basin modelling, seismic survey, acquisition design, seismic processing quality control, regional interpretation, quantitative interpretation, volumetrics and much more. In the future, it will continue to add new capability to provide a fuller picture of places that previously could not be seen.

Ramping up value

The successful development of sites in the Gulf of Mexico and Brazil has already shown the value of GeoSigns, but its capability will keep on growing.

"When the Deimos field was originally explored in 2005, the wells were dry. When the well was placed using better technology to model the basin using seismic, gravity and magnetic data together, we ultimately found that we could develop two fields," says Bachmann.

"Using the technology is an ongoing journey. Fields will only get more complex over time, so it is important that we have our own technology that develops in line with our needs. In the future, we will look at making the system more user-friendly and will improve integration. One of the key issues will be making better use of all the seismic data that is available, including airborne data from aircraft and satellites."

As well as incorporating these no-impact sources of seismic information, Bachmann is targeting the next generation of data sources, including input from ocean-bottom seismometer (OBS) and ocean-bottom cables (OBC) sources. The more data that can be successfully integrated with the modelling and visualisation capability, the more efficient the targeting of test wells and the higher the number of economically viable fields that Shell can bring into production will be.

As the nature of potential reserves becomes more complex and less easily accessible, the more important it becomes to accept that any subsurface modelling system will always be a work in progress. As it is, GeoSigns is constantly upgraded with new algorithms, and there is an ongoing process of integrating more information. The system does not stand alone, but weaves together the capability of many proprietary and off-the-shelf systems that Shell has deployed. Any step forward in those systems, or in the integration architecture, changes the shape and increases the value of GeoSigns.

"The biggest challenge is still the integration of data sources. The various models may not overlap, so we still need to build bridges between different applications. The architecture is still cumbersome and these systems are expensive things to fix. Seismic mapping programmes have been around for 37 years, so we have a long-term roadmap for developing the application further," says Bachmann.

"It is all about finding and producing more oil and gas in a world that is getting more and more complex. This is a very important technology for subsurface teams, and we need to spend more time developing it and supporting the people who make the decision, as well as improving efficiency for end users."