Realising the value of scientific knowledge – geosciences in energy industries – part one:

Published November 13th, 2000 - 02:00 GMT

Geosciences are central to our ability to understand and exploit the subsurface. Commercial geoscientists realize the value of this scientific knowledge by delivering the energy people need and supporting sustainable development.  

 

There have been fundamental advances in geological concepts and huge improvement in the quantity and quality of geological data, and in our ability to visualize and model the subsurface. But geological understanding and imagination are far from redundant.  

 

Finding more elusive resources – within mature fields and in frontier exploration – will require the ability to build on diverse clues to unlock the unseen and understand the unexpected. Success also depends on new ways of working – integrating disciplines, sharing understanding, engaging with others.  

 

Commercial geoscientists rely on the academic community to develop and pass on the wider geological knowledge which is the basis for progress.  

 

Geoscientists have a key role in meeting major challenges – extending oil and gas resources and providing environmental solutions. The threat of climate change demands precautionary action, but need not unnecessarily jeopardize economic development.  

 

The complex energy systems on which people depend must evolve. Meeting developing energy needs in a sustainable way offers a challenging, stimulating and worthwhile career for geoscientists.  

 

It is a privilege for any geologist to be invited to address The Geological Society which has been promoting geosciences for nearly two centuries. It had been doing so for half a century when `Colonel' Drake drilled that well in Titusville, Pennsylvania which began the oil age. It would be nice to think the infant industry relied on developing geological knowledge.  

 

There were certainly advances. J S Newberry suggested marine plants as the origin of petroleum. H D Rogers linked oil migration and location to anticlines, and noted the gravitational separation of gas, oil and water in the reservoir.  

 

David Murray argued that petroleum `is always found in rocks of a porous nature ... and seems to occupy the pores or crevices' and that `plants growing in the geological ages when submitted to heat and pressure, had slowly been distilled into these hydrocarbon fluids.'  

 

And T Sperry Hunt wrote that accumulations depended on `such impermeability of the surrounding and overlying strata as will prevent the outflowing.'  

 

There were also - as always - fierce scientific disagreements. The director of the Pennsylvanian geological survey, J P Lesley, dismissed `the popular notion that petroleum wells are dependent upon anticlines, faults, or other disturbances' as a `pure fantasy of the imagination.'  

 

Perhaps because of this the industry made little use of geology until the end of the century. Wells continued to be drilled near surface seepages.  

 

Among the first companies to use geology systematically was Royal Dutch, in Sumatra from the 1890s. Since then geosciences have become central to our ability to understand and exploit the subsurface.  

 

The approach of academic and commercial geoscientists differs little. We use the same scientific method - with equal scientific rigor - to answer different questions. Commercial geoscientists seek to realize the value of scientific knowledge.  

 

I will start by looking at the development of petroleum geosciences - and the tools we employ - since I joined the industry, and then at what this means for geoscientists.  

 

Then I will look at the new ways of working which drive progress, and the vital relationships between the commercial and academic spheres. Finally, I will discuss what it means to realize sustainable value and look forward to how geosciences may help meet some pressing challenges.  

 

Developing understanding:  

I joined Shell in the mid-1960s from Cambridge, after doing research on the Devonian sediments of Spitsbergen.  

 

My early Shell field work in Spain and the Oman mountains gave access to material that would have been sufficient for several more PhDs, and that was before working in Brunei and Australia at a time of booming exploration.  

 

This access to geological data - expanding exponentially as tools developed - was hugely exciting. So was the ability to see geology as a whole in seismic - rather than having to piece it together from scattered outcrops. And to be able to test one's ideas about that geology with the drill.  

 

I have this picture on my wall at home - from a seismic survey in the Balingian area offshore Sarawak in the mid eighties when I was working in Malaysia. This was the work of an ingenious Malaysian chief geophysicist called Nik Mohamed. For a sedimentologist interested in fluviatile deposition it says it all.  

 

There have been fundamental advances in geological concepts and huge improvement in the quantity and quality of data, and in the way we can use it to visualize and model the subsurface.  

 

Academic geologists and the geological surveys have made an immense contribution - providing the basis for our understanding of what we see on seismic and the sedimentology to open many new areas.  

 

Plate tectonics unified geology for the first time. I was still at Cambridge when Vine and Matthews pieced together the jigsaw of the magnetic striping of ocean floors. It was a vital insight for petroleum geologists, particularly as we probed the continental margins in the 1970s.  

 

Equally important has been our developing understanding of the geological and physical processes governing the generation, migration and trapping of hydrocarbons - although, as I will illustrate, this is still far from complete. 

 

Our new ability to visualize the subsurface has transformed our understanding of structural geology. Our original conceptions were too simple. We can now see the complex fold and fault patterns as they really are - more like shattered glass.  

 

I joined Shell just before the change from analogue to digital seismic allowed data to be manipulated by computer and opened the door to 3D seismic.  

 

When I went to Brunei in 1968 we were in that transition, digitizing earlier analogue data to squeeze more out of it - and a hugely ingenious instrument used for optical stacking of analogue seismic had only just been retired. Four years later some people there - a great deal cleverer than me - were experimenting with 3D.  

 

Since then advances in petroleum geosciences have gone hand-in-hand with those in computing.  

 

Shell was among the first to use 3D seismic commercially in the mid 1970s. At first it was only used to appraise discoveries and plan development. As techniques, tools and our confidence improved, we began to survey larger areas for exploration.  

 

The use of 3D in the North Sea was spurred by the high cost of wells, and then by the need to extend recovery.  

 

Time-lapse - or 4D - seismic tracks the movement of fluids through the reservoir. In Norway, it enabled us to position a well which produced a record 77,000 barrels a day. 4D will be important for maximizing production from mature reservoirs - a key challenge.  

 

Visualization and interpretation technologies have been transformed.  

Large scale visualization centers help share understanding. Connecting them around the world - and extending visualization on workstations - will help us work in dispersed `virtual teams'.  

 

Of course, all this information only means something in the context of geological models. Basin modeling software helps interpreters reconstruct the geological history of an area - understanding when and where hydrocarbons may have been generated and expelled, and how they may have migrated and been trapped.  

 

The real value comes from sharing. Our four-dimensional Shared Earth Model integrates:  

· seismic processing and interpretation,  

· seismic inversion and time-lapse seismic,  

· basin modelling and geochemistry,  

· stratigraphic and fault modelling,  

· dynamic reservoir simulation, and  

· full life-cycle field planning. 

Let me give an example of what such advances have made possible.  

When I joined we could drill in some 200 meters of water and produce in 75 meters.  

 

Today, we are producing from fields in over 1,000 meters - such as our Ursa field in the Gulf of Mexico - and drilling beyond 2,000 meters. This has been a geological as well as an engineering achievement.  

 

We began probing the continental margins in the 1960s. But a global campaign of deep-water exploration drilling in the 1970s was truly an idea before its time. We couldn't find the reservoirs - wrongly assuming the geology would be the same as in shallower water.  

 

In the Gulf of Mexico, our geoscientists looked at the intraslope basins or `potholes' - formed as basins fell into thick, massive salt - beyond the slope. 

 

Turbidite sands had been carried into the deepwater from the shelf. Could they have been trapped in those potholes as they swept past? Oil was produced from turbidities reservoirs in California a century ago. But we didn't understand them. Turbidite outcrops show long, continuous sheet sands.  

 

Using 3D seismic and proprietary imaging software, our geoscientists found similar sands deposited on the lower slopes of the potholes - and learned to detect hydrocarbons in seismic `bright spots'. This new understanding brought a succession of deep-water discoveries - with far higher than normal success rates.  

 

Deep-water economics require very productive wells. Fortunately, these sheet sands in confined basins exhibit superb extent, reservoir connectivity and homogeneity. Wells can deliver over 30,000 barrels a day.  

 

We are now producing over 420,000 barrels equivalent a day of equity oil and gas from the Gulf of Mexico deep water - and still finding and developing fields. Deep water is now a focus of world-wide exploration, particularly on either side of the South Atlantic. Over 35 billion barrels have been found, mostly in turbidities. But this is still a new frontier.  

 

There is still plenty of excitement for geoscientists in this industry.  

 

Source:Shell.com 

By:Mark Moody-Stuart - Mark Moody-Stuart, Chairman of the Committee of Managing Directors (CMD) of the Royal Dutch/Shell Group of Companies and Chairman of The "Shell" Transport and Trading Company, plc. at the Sir Peter Kent lecture, The Geological Society, The Geological Society, London, UK 

 

© 2000 Mena Report (www.menareport.com)

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