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Just around the corner is a new technology which, dependent on who we are listening to, is "The Field of the Future", "The Digital Oil Field", "e-Field" etc. Now one aspect of this vision is that one day in the future we might for example be able to run a field like Samotlor or Rospan from Tyumen, or even Moscow, without exposing workers to Health and Safety risks, and at significantly lower cost. The aspect I want to consider here is the potential avalanche of digital information that can be foreseen and how companies might prepare for it.

Consider a couple of key Digital Oil Field concepts, namely Continuous Seismic Surveillance and Intelligent Wells.

Continuous Seismic Surveillance extends 4D methodology (see below). Offshore, permanent sensors (with up to 4components: X, Y, Z + pressure) are installed in the sea-bed above any oil or gas field in a one-time installation before production starts (ideally at the same time sub-sea production equipment is installed). Then a relatively inexpensive seismic source vessel can sail above these sensors "whenever required" and generate a "repeat 3D". In theory, this could happen as often as once a week at a repeat cost of as little as $100k, giving real-time data for analysis of reservoir dynamics throughout a field's life. Onshore, a similar approach can be envisaged although permanently installed down-hole sensors are perhaps more likely.

Intelligent Wells implies wells that are equipped at completion with down-hole controls and sensors. There can then be a continuous flow of data from these wells regarding pressure performance, inflow distribution, the flowing phase, reservoir saturation and from down-hole geophysical measurements (e.g. seismic and electro-magnetic) and proactive remediation of fluid inflow into the well-bore via remote controlled down-hole zonal control valves and the ability to implement reservoir management without intervention.

What is clear is that the Majors, in partnership with the bigger contractors, have been working on ideas such as these for several years, believing that the leaders will find competitive advantage in their ability to, for example:

• shape production profiles, with individual wells starting-up faster, and field-wide optimisation
• identify unexploited reserves, improving recovery factors
• cut costs, both Capex (less wells) and operating
• remove staff from unsafe environments

For a nice summary of the concepts, the progress that has been made, and a couple of Field case studies, I recommend a paper by Judson Jacobs which can be found on the IHS web-site at http://energy.ihs.com/Resource-Center/Presentations/ under the April 2007, London Symposium heading. It's clear that sensible digital solutions are being invented, tested and implemented. However, to my mind, the most profound point made in this paper is that whilst many individual Digital Oil Field technologies have seen widespread adoption ranging from "Intelligent Completions to 4D Seismic to Real-time Drilling" optimized, collaborative, integrated Operations remain at the proof of concept stage or have only just been shown to be technically and economically feasible.

Apart from the obvious possibility that the number of digits of data that can now be acquired is running way ahead of our ability to assimilate and integrate them, what else might underpin the apparent difficulty in progressing collaboration and integration? At the risk of opening a Grand Canyon divide between some of the petrotechnical disciplines, I'd offer the following thoughts:

By and large, the subsurface disciplines "geologists, geophysicists, petrophysicists, reservoir engineers" have already confronted the digital revolution, and are comfortable with it, not least because of the aforementioned problems set and opportunities offered by the tidal wave of data resulting from 3D and 4D seismic surveys (see below).



In contrast, by and large, the petroleum and production engineering disciplines (and commercial folk too) live in a world of Excel spreadsheets, PowerPoint and SCADA data flows, and those who tend the key (upward) information flows within many organizations seem to regard MicroSoft Office as the leading edge of the digital revolution.

The critical point seems to be that organizations - and related processes, workflows, standards and procurement practices - need re-shaping to support integration and "digital oil field" projects. Acting locally in this way seems to be far more significant than the global pursuit of initiatives such as POSC or PPDM. For a good summary of these ideas, I'd recommend my colleague Alan Smith's paper "How to succeed with your KIDS!" which can be found here: http://www.paras-consulting.com/articles.aspx.

Actually data overload is not new and there are plenty of examples of our ability to collect sub-surface and engineering information running way ahead of our ability to analyse and interpret this data or put differently, we have struggled in the past to turn the massive amounts of data we have into information and thence into knowledge.

A couple of related fragments of geophysical history will help illustrate what I mean.

First of all, let those of us who can cast our minds back to the mid 1980's when, to give them due credit - led by Shell, 3D seismic began to appear on the scene. During this time, I began to be involved in North Sea operations and I can remember walking into 'team rooms' and being confronted with mounds of paper from the very latest technology, a field's new 3D survey. There was so much paper and so little means of dealing with it that to achieve speed of delivery (i.e. to obtain some insight before the field in question came off plateau!), interpretations were commonly based on "every 10th line" - somewhat defeating the objective. This was obviously commonplace around the industry and various semi-exotic analogue interpretation systems appeared. However, the digital seismic interpretation system became the obvious target and to begin with the bigger oil companies attempted to build their own: Standard Oil (Sohio; eventually acquired by BP in 1987) had their SEIS system for example, BP continued with SIIS and Chevron had their own system and so on. Meanwhile some digital entrepreneurs were starting off a couple of companies called Geoquest and Landmark and eventually most, eventually all, of the Majors had the sense to buy rather than build.

The upshot of all this was that by the early 1990's, digital interpretations using all the 3D seismic data were the norm and reasonably accurate static 3D reservoir descriptions could be made available to reservoir engineers for use in their reservoir simulators.



The next episode that's worth some reflection is the move to exploration 3D in the early 1990's. Investment in new vessels, again - to give due credit - led by PGS, allowed seismic contractors to tow many more cables in a much wider pattern, allowing 3D data to be acquired much more quickly and cheaply. However, a major bottleneck now appeared in the processing stage where the massive amounts of data being acquired "several thousand sq kms in some cases" implied a year or more's processing time, threatening the possibility that the first commitment wells on the acreage might be drilled before the 3D was available, again somewhat defeating the objective. The first response to this was for seismic contractors to invest in onboard processing so that a reasonable amount of processing could be undertaken more or less concurrently with acquisition so that a preliminary, interpretable, 3D volume could be made available within a few months of the last shot being fired. Nowadays of course, satellite data transmission, massive computing power and so on means, that a more final data volume becomes available in the same time frame.

The upshot of all this is that an offshore area such as Deep Water Angola enjoys a better than 90% exploration success ratio in Blocks 15, 17, 18, 31 and 32.

Another significant development of the last 10 years has been the growth of repeat or "time-lapse" 3D surveys - usually referred to as 4D - as a component of effective field management (which requires the active monitoring of reservoir properties such as pressure, saturation etc.). The use of 4D increased rapidly in the 1990's. Confronted with this new and extensive type of data, for a while the most significant analytical technique was to process two time-separated 3D data sets in parallel, and then to look at differences at the target reservoir level: interpretation then consisted (more or less!) of looking at the major differences and saying "Hmm, this is probably related to that water injector or that gas injector" or something similar and equally unprofound.

Nowadays, reservoirs are monitored using repeated surface seismic data (4D) together with the acquisition of surface and subsurface well data, and the integrated analysis and interpretation of both to reach a good understanding of how fluids in the reservoir are behaving. Multiple data sets covering many fields are being used in many different ways, varying between simplistic qualitative comparisons to sophisticated models. Such surveys may be used to:

• Identify compartments
• Locate possible infill targets
• Design effective well interventions
• Improve reservoir understanding
• Reduce uncertainty in production forecasting
• Improve estimates of field reserves

The use of 4D is now capable of identifying the pressure changes due to production and injection as well as changes in saturation and solution gas breakout.

My point is obvious, I guess. In each of these episodes, geoscientists were confronted with the (Information Management) problem of an overwhelming rush of data and an operational need to make timely sense of it, similar - in the memorable words of an ex-US colleague - to "a thirsty man holding a tea-cup under the Niagara Falls and expecting to get enough to drink!". Yet, solving the problem led to competitive advantage for the leaders.

And, putting my geoscientist blinkers on just one more time, I'd assert that many sub-surface teams are now organized, and undertake their work, so that the static and dynamic three-dimensional earth model sits at the core of the team's thinking.

Now as somebody who is made slightly dizzy by the notion that my iPod can hold not only every sixties tune that I would wish to listen to but also a significant proportion of those actually written in the sixties, I find this hard to take in and I'm glad that I'm not responsible for delivering the brave new world of the Digital Oil Field.

But the future "winners" in the oil & gas patch will deliver it to their advantage.

Labels: digital oilfield, gas, intelligent wells, oil, seismic

posted by The Rogtec Team @ 16:18 

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