Bioturbation-enhanced flow in low permeability gas prone reservoirs

这项建议将建立在现有的关于在石油勘探和开发中使用遗迹学的研究基础上，包括对生物扰动介质中孔隙度-渗透率增加的研究。目前的研究表明，遗迹化石组合可以增加相对不渗透基质的渗透性和垂直渗透性。新的项目将着重于这些类别在增强孔隙度-渗透率趋势方面的应用。地质介质的渗透率是一种整体特性。因此，如果要预测水流特性，就必须了解沉积物非均匀性的三维排列。不幸的是，沉积物的整体特性占主导地位的小规模的不均匀性是很难评估和数值模拟。忽视这些结构的潜在影响可能导致对沉积岩流动特性的不准确评估，以及对油气藏中渗透率条纹的错误识别或无法识别。这在易产气储层中尤其重要，因为渗透率的微小变化会对储集率、储量计算和产能产生巨大影响。加拿大西部的一个开发区带围绕着上白垩统低渗透气倾向非伴生油气藏。这些油田产自薄层或泥质单元中相对较浅的区域。这些带可以横向延伸和连续，在大多数情况下与源岩互层，天然气是生物成因的，可能是最近生成的。因此，气体不必迁移到储层中，而是会聚集在显示渗透性和孔隙度增强的任何内部区域，例如洞穴系统。这些页岩和薄层砂岩在相、碳酸钙含量、粘土成分、总有机质含量和生物成因结构方面变化很大。感兴趣的区域包括：Milk River地层、Niobrara地层的梅迪辛哈特段、Carlile地层、第二白色斑点地层、贝尔富什地层、鱼鳞地层和维京海盗地层。

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.