USGS National Assessment of Oil and Gas Project - Uteland Butte 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 herein 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.

评估单元（Assessment Unit）是国家未发现油气资源评估项目中用于开展未发现油气资源评价的基本单元。评估单元的定义依托于更高层级的全油气系统（Total Petroleum System）范畴。本文所呈现的评估单元，由负责对应油气省的地质学家通过解释、定义与绘图划定其地理边界，其内涵为全油气系统内一组具有相似地质、地理与时间属性的已知或推测油气藏集合，涵盖烃源岩、成藏时序、运移路径、圈闭机制以及烃类类型等特征。从地质角度而言，评估单元的边界被定义为构成该单元的各类地质要素的范围，例如储集岩分布范围、地质构造范围、烃源岩范围以及盖层岩性分布范围。唯一的例外情况是与联邦-州属水域边界接壤的评估单元，此类情形下，联邦-州属水域边界将作为评估单元边界的组成部分。