PESGB/AAPG Technical Mastery Course – London

Source to Sink Systems: The Creation and Sorting of Clastic Reservoirs

Thank you to Dr Laura Fielding (Petryx Limited) for this review

The first PESGB Technical Mastery course of the year was kicked off by Duncan Macgregor and Philip Hirst in London on the 8^th January. The one-day course aimed to address the hot topic of Source to Sink (or S2S if you’re down with the kids) by exploring various techniques that are becoming increasingly popular for reconstructing past drainage systems. It had a particular emphasis on the need to integrate multiple provenance and palaeodrainage techniques in order to gain the most accurate palaeodrainage reconstructions. The course began with Philip Hirst taking us through the sedimentological principles that underpin Source to Sink studies.

This was followed by Duncan Macgregor walking us through the different control that come in to play when reconstructing a drainage system. Case studies were used throughout in order to demonstrate real-world Source to Sink systems. These included a strong focus on Africa and the Gulf of Mexico.

As we headed into the afternoon, we began our first exercise using an example from Namibia where we had to use our new-found knowledge to construct a play map for the offshore. This was a great way of qualitatively illustrating the reservoir quality potential of each of the given source areas whilst considering the length and topography of the individual rivers and any effects that this may have on the quality of sediment reaching the depocenter.

This then led us to look more closely at the ‘Sink’ and controls on major sediment outlets and turbidite reservoirs around the world. I was particularly interested in this section of the course as it shed some light on the sometimes-vague subject of volumetric calculations and sediment budgets. Luckily, I was rather familiar with the case study used to demonstrate the work flow as we were tasked with trying to balance the observed volume of sediment in the Nile delta with that of its vast hinterland.  Pros and cons were discussed as to whether this technique would be useful for upgrading or downgrading reservoirs in all Source to Sink systems and uncertainties were covered in detail in order to avoid bias calculations.

The day was rounded off by looking at the economical context of Source to Sink studies. Duncan and Philip showed some examples where an eye watering $2 billion could have been saved if these multidisciplinary studies had been used to predict reservoir location and quality.

For many of us, the course served to reinforce the increasing importance of Source to Sink studies, particularly in frontier regions and high-risk areas. However, the main drawback to these studies seems to be the large amount of time required to conduct such a thorough, multidisciplinary analysis of an area and that this can not usually be achieved by operators in time for licensing rounds. Duncan ended by emphasising the need for cooperation at an academic and service company level in order to successfully meet the industries increasing requirement for Source to Sink studies.