Отправлено: 15.04.08 01:37. Заголовок: Naturally Fractured Middle East Carbonates Reservoirs Characterization, Modeling, and Simulation

Naturally Fractured Middle East Carbonates Reservoirs Characterization, Modeling, and Simulation
12-16 October 2008
Sharm El Sheikh, Egypt

Following the June 2006 SPE Forum on Characterization and Modeling of Naturally Fractured Reservoirs held in Colorado, USA, it is proposed to organize in 2008 a forum dedicated to the same topic but focusing on the giant Middle East naturally fractured carbonate reservoirs and their emerging challenges.

Naturally fractured reservoirs contain vast amount of hydrocarbons in the Middle East and are among the most complex reservoirs to characterize, model, and manage. This complexity is due to the interplay of the matrix characteristics that can be highly heterogeneous in carbonates and the fracture network, an intricate geological feature on its own where fractures can be open or closed and can be organized in a diffuse and/or concentrated arrangement. Associated uncertainties include the detection and characterization of the fracture network in the well bore, our knowledge of fractures between wells, the fluid flow behavior within the fracture-porous system, and our ability to model such behaviors. Our target is to improve the tools, processes, and workflows that maximize our understanding and value from these reservoirs.

Most of the giant Middle East carbonate reservoirs have been producing for many years at rather low rate and the potential issues related to fractures only start to be felt in the production, mainly by water cut increases that were not expected. The geological models describing these reservoirs are often not comprehensive enough to properly integrate the intricate nature of fracture in the flow behavior at field scale. Furthermore, the impact from fractures can be masked by the effect of thin and laterally continuous high permeability streaks and the real importance of fractures is often realized only late in the field history. The success of incremental development plans and particularly infill campaigns in most of the giant carbonate reservoirs is likely to be very sensitive to the accurate characterization and modeling of fractures. Precise placement of horizontal wells with respect to fractures is particularly critical to optimize hydrocarbon production while minimizing/delaying early water and/or gas breakthrough, hence maximizing the economic value of these reservoirs.

Amongst the key challenges are the effective use and integration of the vast amount of data that are already available, the accurate characterization of fracture in the boreholes and between wells as well as the availability of adequate computer hardware and applications for the desired accurate fracture characterization of large static and dynamics models. In addition, economically producing reservoirs require evaluating the recoverable reserves and the parameters involved in this process, and predicting optimum well location of the producers/injectors and their performance versus time. Not an easy task in fractured reservoirs as the predicted production profiles associated with various production mechanisms are significantly affected by the assumptions on the fractured network characteristics and on the fracture-matrix interactions.

Will the recent advances in 3D seismic acquisition, processing and interpretation be the enablers in fracture modeling at field scale? Is the meticulous seismic attributes extraction from high resolution and high quality 3D seismic emerging as a key technology in fracture characterization between wells? Probably, one of the most promising techniques is the integration of velocity and amplitude versus offset anisotropy data. Detailed investigation around wells might be considerably improved with 3D Vertical Seismic Profiling (3D VSP), inter-well tomography and micro-seismicity. Integration of these new types of geophysical data with core, log and production data in the framework of geomechanics and stress analysis will be one of the challenges of the coming years.

One of the key challenges will likely be the up-scaling of usually very large and detailed geologic models to flow models that are truly predictive. How do we efficiently integrate the key dynamic well tests and production data? What are the benefits of the Discrete Fracture Network approach and how do we address it? At what stage do we need to model the intricate dual porosity-dual permeability media? Will the improvement in workflows and computer power significantly reduce cycle time, an optimization that is required to properly address uncertainties by evaluating a selection of scenarios and running the numerous realizations associated with probabilistic methods? What about the value of outcrops as analogues, how can we scale-in field observations? What are the effects of the additional fracturing that we are inducing during pressure maintenance and how can we accurately monitor and model this phenomenon? Finally, are there unique laboratory experiments that could help with the critical characterization of the fluid/rock system interactions?

Learning from fractured carbonate reservoirs that are more advanced in their production life is likely to be extremely beneficial to others in terms of risk reduction by anticipating production problems potentially linked to fractures that were either not modeled in enough details or even ignored. The development of increasingly thinner and tighter layers may require additional effort in characterizing and integrating fractures in static and dynamic models.

The forum will improve our understanding of fractures in carbonate reservoirs and specifically will help to determine whether fractures are important to hydrocarbon producibility and to analyze the impact of fracture system in optimizing reservoir management.
Who should apply: Individuals involved in the management of these reservoirs including reservoir engineers, structural geologists, geophysicists, geomechanics experts and software development interest groups.

http://www.spe.org/spe-app/spe/meetings/FSME/2008/index.htm