National Assessment of Oil and Gas Project - Northern Alaska Gas Hydrate Total Petroleum System, Northern Alaska Province (001) Assessment Units

The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown here as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set of known or postulated oil and (or) gas accumulations sharing similar geologic, geographic, and temporal properties within the Total Petroleum System, such as source rock, timing, migration pathways, trapping mechanism, and hydrocarbon type. The Assessment Unit boundary is defined geologically as the limits of the geologic elements that define the Assessment Unit, such as limits of reservoir rock, geologic structures, source rock, and seal lithologies. The only exceptions to this are Assessment Units that border the Federal-State water boundary. In these cases, the Federal-State water boundary forms part of the Assessment Unit boundary.

评价单元（Assessment Unit）是全国油气资源评价项目（National Assessment Project）中用于未发现油气资源评估的基本单元。评价单元需在更高层级的含油气系统（Total Petroleum System）框架内进行定义。本次展示的评价单元由负责该地质省的地质学家通过解释、界定并绘制的地理边界确定，其涵盖一组已知或推测的油气藏，这些油气藏在含油气系统内具备相似的地质、地理及时间属性，包括烃源岩、成藏时序、运移路径、圈闭机制与烃类类型等。评价单元的边界以构成该单元的各类地质要素的分布范围作为地质界定依据，例如储集岩、地质构造、烃源岩及盖层岩性的分布范围。唯一例外的是与联邦-州际水域边界接壤的评价单元，此类情形下，联邦-州际水域边界将作为评价单元边界的组成部分。