Dry holes – did we have the information to prevent them?
Feature Articles, May  29  2009 (Digital Energy Journal)

- In many dry hole reviews, it emerges that the technical team had identified problems with the well – but the information was lost amid all the other information involved. How can this be prevented?

By David Bamford, consultant editor of Digital Energy Journal, a non-executive director of Tullow Oil and past head of exploration with BP

David Bamford

My recollection of the (too many) dry hole reviews that I have been involved with is that oftentimes the reason the prospect under review failed was identified by the technical team well in advance of the decision to drill the well.

Unfortunately, the spotting of this fundamental problem was obscured and overtaken by all the other information that typically swims around as a decision to drill is made.

Also, it is a frequent observation that when technical explorers describe a prospect as ‘high risk’, typically with a chance of success of worse than in 1 in 4 or 1 in 5, they are actually indicating either that there is some fundamental problem with the prospect or that they do not really believe the hydrocarbon volumes that they have attributed to the prospect.

In these cases, the exploration team has identified a ‘loose end’ in the prospect description which is the reason why the prospect will not actually work.

I am suggesting that the most profound impact will be in the correct identification of risk: note I am talking here of identification of risk not its quantification (which is a whole other story).

So here is my assertion – the most significant way for a company to improve its exploration performance would be to stop drilling dry holes or, put slightly differently, to stop drilling dumb holes where there is a clear ‘loose end’ which means the prospect will fail.

But there’s the rub – it is exceedingly difficult to spot a true ‘loose end’ amidst the plethora of data and information of different quality and dimensionality that is contained in a typical prospect evaluation.

Integrating data

In exploration many different types of data need to be integrated before we can offer knowledge about a petroleum system, a play, a series of prospects, or a prospect we wish to drill, and talk sensibly about volumes, uncertainties and risks.

At the risk of gross over-simplification, the technical process in exploration can be represented by the pyramid shown below (note that this is just one face of a pyramid – another might describe the whole process of Portfolio and Prospect Inventory management, for example).

Click to enlarge

In this technical face, various different types of data (in blue) combine to give particular insights (in green) which are then integrated to reach a key stage in the evaluation (in black):

Any one of these elements involves a potentially unique mixture of processes, models and interpretations.

As an example, consider the following three:

Regional Geological Framework

Building such a framework necessitates an a la carte selection from (seismic) chrono-stratigraphy, petroleum system types, play fairways, regional cross-sections, gross depositional environment (GDE) maps and common risk segment (CRS) maps.

Data manipulation and display commonly uses GIS products (such as ARC_GIS) but viewing an integrated final Framework, such as the simultaneous display of regional seismic lines, seismic stratigraphic interpretations and GDE maps, is both difficult and rare.

Advanced Geophysics

What is meant here is an a la carte selection from high resolution gravity/magnetics, electro-magnetics (e.g. CSEM), specialist Seismic (e.g. multi-component; multi-azimuth; wide-angle), lithology & fluid prediction from seismic – including AVO for lithologies, perhaps fluids, direct-hydrocarbon-detection (‘flat-spots’ etc), rock physics (including stress, pressure prediction).

It’s a real challenge to workflow processes to integrate these numerous information strands and to be able to view several outputs simultaneously.

3D Sub-Surface Models

The key word is again Integration, enabling multi-disciplinary team-work, by providing a 3D geological “framework” - containing multi-attribute cells allowing specification of for example lithology, porosity and permeability, stress and pressure, Sw - allowing these teams to resolve uncertainties and spot “Loose Ends” (see below).

The a la carte nature of these technical exploration processes raises profound issues with respect to both work-flow processes and comprehension.

How can the team comprehend multi-faceted and sometimes conflicting interpretations, both efficiently and effectively?

The process can be rather cumbersome, bringing both inefficiency and ineffectiveness to exploration management and decision-making; optimization will bring important benefits in terms of both cycle-time and cost reductions.

Critical issues

One critical point seems to be that organizations - and related processes, workflows, standards and procurement practices - need re-shaping to support “integrated exploration” projects. Acting ‘locally’ in this way seems to be far more significant than the ‘global’ pursuit of initiatives such as Energistics or PPDM.

Another issue is that there are no applications packages which span the entire exploration technical process.

Regional work tends to rely on GIS products such as those provided by ARC. The interpretation workstations offered by Schlumberger and Landmark typically address only a subset of the data manipulation and interpretation described by the pyramid, for example aspects of 3D seismic interpretation, the use of well data; definition of trap, seal and reservoir. There are a number of ‘niche’ products that focus on particular aspects of the process, for example the interpretation of seismic attributes, their relation to rock physics and so on. Yet another set of products deal with risk, uncertainty, volumes, development economics and so on.

As a consequence, much exploration management and decision-making still lives in a world of Excel spreadsheets and PowerPoint, 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: one result is an emphasis on internal marketing rather than collaboration and understanding.

Visualisation

For me one of the most exciting recent tools of collaboration is Visualisation which gives us something we've never had before - the ability to give all the people involved in an exploration project a common mental picture of the sub-surface on which they are working, a rapid and common understanding of something they will never actually see.

Visualisation is an immensely powerful stimulus for collaborative working styles, changing the boundaries of teams, and bringing together people of very different disciplines - all applying their skills to a common objective, and as a result of the technology being able to reach decisions in a matter of days rather than weeks or months.

Actually that sounds like “management speak”! In reality, I can count on the fingers of one hand the number of times I’ve seen a truly integrated display; for example, a review of a regional geological framework where I could simultaneously view plate tectonic reconstructions, regional potential field maps, a regional seismic data base, seismic stratigraphic and facies interpretations, migration pathways (“plumbing”!), gross depositional environment maps.

Integrated Exploration is tough to do, challenging to deliver…… but the future “winners” in the oil & gas patch will deliver it…..to their advantage.

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