Bioturbation-enhanced flow in low permeability gas prone reservoirs

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This proposal will build on existing research on the use of ichnology in petroleum exploration and exploitation including the examination of porosity-permeability enhancement in bioturbated media. Current research indicates that ichnofossil assemblages can enhance the permeability and vertical transmissivity of a relatively impermeable matrix. New projects will focus on the application of these categories in the enhancement of porosity-permeability trends.The permeability of geological media is a bulk character. Thus, the three-dimensional arrangement of sediment heterogeneity must be understood if flow behavior is to be predicted. Unfortunately, the bulk characteristics of sediment dominated by small-scale heterogeneities are difficult to both assess and numerically model. Overlooking the potential impact of these structures can lead to inaccurate assessments of the flow characteristics of a sedimentary rock, and misidentification or non-recognition of permeability streaks in a hydrocarbon reservoir. This is especially important in gas-prone reservoirs where slight variations in permeability can have dramatic effects on storativity, reserve calculations and deliverability. A developing play in Western Canada revolves around Upper Cretaceous low permeability gas-prone non-associated reservoirs. These fields produce from relatively shallow zones in thin bedded or muddy units. Such zones can be laterally extensive and continuous and in most cases are interbedded with the source rock and the gas is biogenic in origin and was probably generated recently. Therefore the gas does not have to migrate into the reservoir but will accumulate in any internal zones that show permeability and porosity enhancement such as burrow systems. These shales and thinly bedded sandstones are highly variable in: facies, calcium carbonate content, clay composition, total organic content, and biogenic structures. Zones of interest include: the Milk River Formation, the Medicine Hat Member of the Niobrara Formation, the Carlile Formation, the Second White Specks Formation, the Belle Fourche Formation, the Fish Scales Formation and the Viking Formation.