Technical Program
Session 1: The Size of the Prize
Session Managers: Roy Hartley, Gerrit Nitters, Jill Prabucki, Helen Hichens
Worldwide there are large volumes of gas stored in very low permeable formations. It has been estimated that for every
m³ of gas in conventional reservoirs, there are about 10 m³ locked in micro and nano Darcy rock. The total volume
of GIP estimated varies widely but is large. One company even proposes 310 – 510 T m³ GIP(10800 - 17800 Tcm)!
However, using existing technologies, the recoverable volume is perhaps as low as 100Tcm. Production of this gas
requires a dedicated effort with respect to technology development. There is a considerable technology gap, with offshore
development presenting added complexity, both from an economical as well as technological aspect.
Nevertheless, in the United States production from such reservoirs already forms a major contribution to the energy
supply chain. In other parts of the world, the production is less advanced or almost nonexistent. In the first session of the
workshop a number of keynote speakers will address the situation worldwide and then focus in on Europe and what needs
to be done to increase the development of tight gas reservoirs in Europe, both on and offshore. The session will be finished
with three case studies of field developments or experiences.
Session 2: Reservoir Characterisation—Where do we go from here?
Session Managers: Roger Skinner, Martin Jentsch, Raymond Godderij, Jos Okkerman
Key issues for most tight gas projects are questions like: What do we really know about our reservoirs flow potential? What can we realistically find out about heterogeneities in the reservoir, its connectivity and what are the limits imposed on us by the tools available? What do we really need to know? Where can we simplify?
Largely based on case studies, this session aims to address such questions on several scales. On the micro scale we will
share learnings on fluid saturation and permeability, petrophysical data acquisition and SCAL in tight gas cores. On the
meso scale we will talk about the practicalities of including actual stratigraphy, how we can deal with connectivity and
heterogeneity in the reservoir and what the limitations of our reservoir models are. On the macro scale we will look into
well test analysis e.g. the use of mini-frac injection analysis to determine macro permeability and what the frac process
itself may reveal about the reservoir.
On all scales the recurring subject will be data acquisition: what can we recommend to acquire, what tools do we have, what is the value of information and where do we arrive at the limits of what we can and need to know to get the maximum recovery from tight gas reservoirs.
Session 3: Fracture Performance: Can we get what we want? Can we get what we need?
Session Managers: Martin Jentsch, Josef Shaoul, Gerrit Nitters, Erik Schrama
Tight gas reservoirs typically require hydraulic fracture stimulation to achieve economic production rates. This session will focus on key issues involved in the design, execution and evaluation of hydraulic fracture treatment performance. Each topic will include a case study to illustrate real-world problems and solutions relevant for tight gas wells.
Fracture design topics include: What is sufficient fracture conductivity and how can we achieve it? Do we create the frac geometry that we design for? What are the special design issues for transverse fractures and where do we prefer longitudinal fracs?
Fracture execution topics will deal with fluid and proppant selection for tight-gas stimulation, perforation versus CT jetting, and issues related to flow-back.
Fracture performance evaluation topics include use of tracers (tracing fluid vs. proppant), methods of evaluating postfracture performance without pre-fracture welltest data, and use of reservoir simulators to improve post-frac history matching.
Session 4: Well Designs/Concepts
Session Managers: Wouter dÉngelbronner, Jos Okkerman, Gerry Coghlan, Raymond Godderij
The emphasis is on field implementation of well designs/concepts that result from flow-test analysis, reservoir characterisation and inflow performance predictions.
An introductory presentation will consider the onshore, US tight-gas
industry and contrast it with Europe both on- and off-shore, exploring
how the differences translate into different well and completion
designs. It will highlight how lower well densities, reservoir
uncertainties/heterogeneity, execution risk (real and perceived) and a
different cost base in Europe combine to steer development choices.
The session will highlight practical limits to “optimal” well designs
(e.g. horizontal, multiple-fractured wells) and explore the potential
of alternative approaches and some issues these can introduce.
Limited reservoir contact and drainage volume can limit the potential
for ‘cheap’ vertical wells in tight gas. Open-hole versus cased-hole
fracturing requires consideration of several issues including
borehole stability and sand control. Limitations in drilling v. long
horizontal sections and limits to wellbore access can set practical
constraints on subsurface conceptual designs. Monitoring requirements
must be anticipated and incorporated in completion design.
Session 5: Cost and Value
Session Managers: Roy Hartley, Erik Schrama, Jill Prabucki, Gerry Coghlan
This session will consider cost optimisation and the creation of value. In particular what can be learnt from the North American “factory” approach to tight gas development compared with the current European “bespoke” approach. A case study of a North American large-scale, integrated field development and its emphasis on cost efficiency will be presented. As a follow-up to the ATW in April 2008, there will be a review of progress in forming “frac clubs” in Europe (on- and offshore). The potential to reduce the cost burden for tight gas development in Europe will be discussed, from more alignment of operator and service provider mind-sets and for greater collaboration and synergy between operators. Breakout sessions will aim to categorise costs, value and risk— with due account of the differences between the onshore and offshore.
