Updated: Jul 2, 2018
PetroMall Director David Bamford shares some of the secrets to evaluating complex reservoirs.
Fractured reservoirs have been encountered since the early 20th Century, are the dominant type in the Middle East, and inter alia offer intriguing possibilities as a basement play in NW Europe, as evidenced West of the Shetlands in the UKCS.
And yet they can be hard to understand, and therefore tricky to develop once found. Flows from vertical wells are often disappointing, vertical gas-oil-water distributions in vertical wells can show unusual variation, production decline rates are oftentimes very different from modelled predictions.
Engineers and geoscientists who have the experience of such reservoirs have the deep knowledge to understand such phenomena and to understand which technologies can help.
It is important to know what fracture orientations are present in a reservoir and then which fracture sets are open and which are closed.
Multi-component seismic can probe a reservoir to reveal fracture orientations and ‘porosity’, to give a static description. A dynamic description becomes available once a field has been in production for some time and directional flow relationships cab be seen (for example, between all injectors and all producers).
This provides the opportunity for the adroit directional drilling of horizontal wells, potentially turning previously poor prospects into real financial opportunities.
David Bamford is a founding director of PetroMall and is well known in the oil & gas industry both as an explorer and a geophysicist. He is a former Chief Geophysicist at BP and serves as a non-executive director to several key industry companies.