The objective of the project is to provide the scientific and industrial communities with a tested, standardized research protocol for estimating methane emissions from onshore oil and gas systems in a given natural gas production basin anywhere in the continental US. This protocol shall include advancements in both bottom-up and top-down components, aiming to reconcile potential differences between results from the two approaches. Reconciliation is defined as reducing the gap observed in prior studies between inventories and measurements with the goal of achieving the closest agreement possible considering relevant uncertainty analysis for each approach.