The Digital Twin (a virtual, dynamic, and integrated representation of a physical asset or process over its life cycle) is one of the latest digital technologies attracting significant industry attention. Yet, most Digital Twins in operation in E&P today focus on one or more discrete asset functions (e.g., drilling, maintenance, production). IHS Markit records very few attempts to capture the entire asset in a Digital Twin. What is hampering industry-wide adoption? How are Digital Twins driving integration across functional groups and across the E&P lifecycle? What are emerging technical and organizational challenges that may impede value realization and sustainment?