Bioturbation-enhanced flow in low permeability gas prone reservoirs

这项建议将建立在现有的石油勘探和开发技术应用研究的基础上，包括对生物扰动介质中孔隙度-渗透率增强的研究。目前的研究表明，鱼化石组合可以提高相对不渗透基质的渗透率和垂直透过率。新的项目将侧重于这些类别在提高孔隙度-渗透率趋势方面的应用。地质介质的渗透率是一个整体特征。因此，如果要预测流动行为，就必须了解沉积物非均质性的三维排列。遗憾的是，以小尺度非均质性为主导的泥沙体积特征难以评估和数值模拟。忽视这些构造的潜在影响，可能导致沉积岩流动特征的评估不准确，以及油气储层渗透率条纹的错误识别或无法识别。这在易含气油藏中尤为重要，因为渗透率的微小变化会对储气能力、储量计算和产能产生巨大影响。加拿大西部的一个开发区围绕着上白垩统低渗透易产气的非伴生储层。这些油田产自相对较浅的薄层或泥质地层。这类带横向扩展，连续，多数与烃源岩互层，天然气为生物成因，可能是近期形成的。因此，天然气不必运移到储层中，而是会积聚在任何显示渗透率和孔隙度增强的内部区域，如洞穴系统。这些页岩和薄层砂岩在相、碳酸钙含量、粘土组成、总有机质含量和生物成因结构等方面变化很大。感兴趣的区域包括：Milk River组，Niobrara组的Medicine Hat成员，Carlile组，第二白色斑点组，Belle Fourche组，鱼鳞组和Viking组。

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.