Integrated Asset Management (IAM) is the vision of IT-enabled transformation of oilfield operations where information integration from a variety of tools for reservoir modeling, simulation, and performance prediction will lead to rapid decision making for continuous optimization of oil production. In this paper, we discuss the similarities and differences of IAM applications and typical e-Science applications. We then propose an architecture for a workflow system for IAM based on the four key requirements: support for creation, orchestration and management of workflows including those involving legacy tools, support for audit trails and data quality indicators for data objects, usability and extensibility. Our architecture builds upon current research in the scientific workflow area and applies many of its learnings to address the requirements of our system. We propose some implementation strategies and technologies and identify some of the key research challenges in realizing our architectural vision.