Finding & Exploiting new petroleum resources in Europe

David Bamford - Director - Finding Petroleum

Oswald Clint - Senior Analyst - Bernstein Research

Neil McMahon - Managing Partner - Kimmeridge Energy

John Weston - Technical Director - Ulysses Petroleum Management

Ian Roche - Managing Director - Aurora Energy Resources Ltd

Tim Harper - Founder & Director - Geosphere Ltd

Applying US hydraulic fracturing technology to UK shale exploration wells demands and encourages adaptations for both social and technical reasons. Exploration wells must not only test and hopefully demonstrate commercial potential but also provide reassurance to an uninformed and often misinformed public. In the UK, we have a far more concentrated population, usually better quality agricultural land and a greater challenge to gain the necessary social licence. In the eyes of many, including many politicians who have banned its use or plan to do so, hydrofracturing is viewed more as a bête noire, or worse, than a basic component of the petroleum engineer’s toolkit. Risk, real and perceived, and public inconvenience must be minimised. The present US technology is inefficient in that a minority of fracture stages produce the majority of a well’s production. Unproductive stages and unproductive fractures within clusters are not simply expensive and a source of unnecessary vehicle movements but may be actually detrimental to a well’s productivity. Empiricism has often masqueraded as design. Much greater quantities of materials are wasted than if the situation were reversed and the majority of fracture stages contributed to the flow. Reducing cost, minimising public inconvenience, gaining social acceptance and increasing well productivity go hand in hand.

The results of a stimulated exploration well must be extrapolated or interpolated to other areas of a licence. To maximise the value of an exploration well the results should contribute to, and accelerate, the exploration learning curve. Hydraulic fracturing is a fundamentally a mechanical process. At least two basic geomechanical requirements must be satisfied if the exploration of a licence is to be optimised. First, some understanding must be gained of the processes controlling the effectiveness of multistage fracturing at each well; second a licence-wide model of the distribution of stress and the relevant mechanical properties must be constructed and progressively refined. This implies a programme of data collection, balancing cost against immediate and future benefit.

In relation to well completion needs, this talk will concentrate on reservoir stress state with brief attention to reservoir rock properties. How and why each aspect of stress state affects well and completion planning will be discussed. The focus will be on less widely recognised but basic reservoir geomechanical realities, their constraints on fracturing operations and the justification for constructing licence-wide and local geomechanical reservoir models. A brief review of the basic data sources for building a geomechanical model of a licence prior to drilling and during an exploration programme in the UK, will be included, and what can be achieved for little cost.




After wellsite and seismic survey experience, Tim Harper worked for a US consultancy before joining BP to build a technical service capability in hydraulic fracturing. At this time, stimulation vessels were just entering the N. Sea, requiring changes to the traditional US approach to suit UK offshore operations. Achievements included major cost savings in field development and joint receipt of the Royal Academy of Engineering’s most prestigious prize for advances in hydraulic fracturing. This is the only occasion the award has been made for subsurface engineering. An invitation followed to give a Friday Evening Discourse at the Royal Institution, a memorable challenge. In addition to the completions technical service, he devised and managed a programme to limit the risk to wells drilling through active faults in Colombia and the risks to surface facilities. This included monitoring of microseismic activity during drilling and testing. With Geosphere, he has worked on diverse geomechanical aspects of typical drilling and completion problems. After assisting Cuadrilla to investigate a well-known instance of induced seismicity, he has mostly concentrated on the fracturing of unconventional reservoirs.
Tim Harper obtained a PhD in engineering at Imperial College studying fluid flow in fractured rock after obtaining an MSc. in Structural geology and rock mechanics

Geosphere Ltd
For more than 20 years, Geosphere Ltd. has provided geomechanical services to operators and other consultants. For the last five years we have worked mainly in the UK and developed procedures to describe geomechanical conditions prior to exploration drilling. Geosphere has also supported a programme of research, developing software to examine the interactions between numerous natural fractures and faults, and multiple hydraulically fractured wells subject to various stress states and fracturing histories.

Nick Terrell - Chair - Exploration Task Force

Joshua May - Sales and Marketing Manager - PGS

Mark Enfield (PDF) & Rob Gill (Advisian) - - Kimmeridge Energy