Preliminary Technical Agenda

Tuesday, 23 February

Session I: Stimulation Challenges in Mature Basins - Fields in Their Golden Years

Session Managers: Kent Bonner and Michael Ross

The North Sea has been a powerful force for delivering oil and gas reserves to market for over four decades and continues to be a great opportunity for many companies. For production to maintain at economical levels, however, heavy investment is required for infi l drilling and interventions to shore up the stock of existing wells. A key enabler of productivity improvement is well stimulation through means of hydraulic fracturing with proppants, acid fracturing and matrix acidizing. These technologies do not come without challenges, (especially in mature basins where technology and cost efficiency are both of prime importance. It is the intention of this session to address the issues and promote discussion on how stimulations are being designed and executed successfully in one of the most challenging mature basins in the world.

The debate will focus on issues such as:

• The major challenges of stimulation in mature basins
• Understanding the formation damage mechanism and applying the right solution
• The increasing need for cost-effective stimulation techniques
• Best methods of stimulation candidate selection
• Optimising stimulation design to suit existing completions (horizontal, deviated, vertical)
• Low reservoir pressures and how to overcome the post treatment clean-up headache

Session II: Stimulation Challenges in New Plays and Developing Projects - The Next Generation

Session Managers: Bjorn Berntsen and Juan Velasquez

This session will address the future challenges of stimulation in the North Sea. The North Sea still holds large quantities of oil and gas in low permeability reservoirs which cannot be economically produced without applying some sort of stimulation technology. In addition, there are many smaller, marginal fields which require cost-effective stimulation. Exploring for new plays in the North Sea has also revealed a new and challenging type of reservoir, namely fractured basement rock. This type of unconventional reservoir is likely to have limited permeability and fl ow capacity, and potentially deep damage from drilling operations.

Some of the questions to be addressed:

• What state-of-the-art and new technologies are applied in the emerging/active areas around the world and which are applicable to North Sea developments?
• How can we transfer “know-how and why” to North Sea conditions?
• What are the enablers that will make the technologies achievable?
• What will be the main stimulation issues for HPHT discoveries/fi eld with poor reservoir quality?
• How can fractured basement rock be stimulated? Is stimulation required? Are there fi eld examples?
• What role should stimulation play in a discovery/appraisal programme?

Wednesday, 24 February

Session III: How Do We Stimulate and What Can We Get?

Session Managers: Erik Jakobsen and Gerard Glasbergen

Different stimulation strategies have been applied in carbonates. Hydraulic fracturing, fracture acidizing and matrix acidizing have all been implemented successfully in the North Sea. This session will focus on the challenges of selecting the appropriate technique and the correct implementation thereof. The ultimate goal of sustained production increase in carbonates can be achieved in different ways. Two key questions to address are 1) if acid or proppant fracturing will be the preferred method and 2) how much production increase can be realistically expected for each of these methods. Production modelling and its challenges will be part of the discussion. Design considerations and modelling to optimise stimulation treatments in carbonate reservoirs will be discussed. Model validation and treatment diagnostics are included in this session with the goal to understand how good the predictive models are and what calibration is needed for subsequent treatments. North Sea case histories will be included to cover the selection of the stimulation method, the design considerations and the validation of the treatment.

The questions to be addressed include:

• How do we select the right stimulation technique for NS carbonates?
• What is the way best way to design a single acid fractures?
• How can we verify stimulation results?
• How bad are the predictive models to acid fracturing?

Session IV: Sandstones - Squeezing the Last Drop from North Sea Sandstone Reservoirs

Session Managers: Fazrie Wahid and Chris Tzinieris

In this session, we will focus on the various aspects of sandstone stimulation. The fi rst challenge pertains to the selection of stimulation type based on reservoir criteria, e.g. matrix acidizing vs. frac pack vs. massive hydraulic fracturing. Next, an appropriate stimulation treatment must be designed to achieve maximum reservoir contact and optimal long-term productivity. In addition, simulation (forecasting) and modelling (history matching) aspects of pre- and post-stimulation stages should be considered. Finally, well clean-up following stimulation should be adequately planned for. Auxiliary aspects to sandstone stimulation, for example looking the management of transient and permanent damage, (e.g. impact on condensate banking and scale build up) will also be discussed.

Some of the topics to be discussed include:

• Sandstone acidizing vs. frac pack to remove damage
• Well configuration and stimulation technique for maximum reservoir contact
• Pre- and post-stimulation modelling and evaluation
• The impact of reservoir fl uids on sandstone stimulation

Thursday, 25 February

Session V: Overcoming Existing Limitations – Breaking Free from Current Constraints

Session Managers: Stewart Anderson and Roberto Martignoni

The interest in well stimulation has grown signifi cantly in the North Sea over the last fi ve years as companies strive to develop and optimise ever increasingly challenging and complex reservoirs. The market for vessel-based stimulation services has noticeably changed in this time frame and is continuing to evolve. The availability and fl exibility of rig-based equipment has increased, but cannot meet all needs. New technologies are being considered but have yet to gain a firm foothold.

Poster Session

Poster sessions will be held throughout the workshop. Posters can be topic related stimulation challenges or recent success stories. They may cover activity in mature basins or new developments and disciplines related to both sandstone and carbonate reservoirs. Novel ideas to over coming future limitations are also encouraged.

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