Chalk Reservoir Management through Rock Physics Diagnostics - Field Examples from the Danish North Sea (SPE 154870)

With improvements in 3D seismic products and an increasing number of 4D examples from North Sea chalk fields, the usages of rock physics is becoming more and more accepted as an enabler for detailed reservoir characterization and monitoring of the dynamic behavoiur of the reservoirs. In order to manage the fields optimally, it becomes increasingly relevant for the asset team to understand the effective elastic properties of the reservoir rock recorded from seismic, well logs and laboratory experiments and the related the changes that production and water injection may induce. Through a series of field examples this paper decomposes and quantifies the effect of lithology and porosity variations, fluid replacements, pressure changes in a reservoir management context using rock physics fundamentals. The examples includes both 3D and 4D seismic observations and the case examples are backed up by well log and laboratory data. The paper summarizes on how rock physics insights on North Sea chalk has increased the understanding of the chalk reservoirs and directly impacted reservoir management by integration of quantitative geophysical interpretation with solid reservoir engineering and proven geoscience processes. On basis of the examples the paper concludes that an intgrated approach to field development and reservoir management evidently includes quantitative geophysical interpretation in order to optimize hydrocarbon production from tight chalk fields.