Well engineers face ever increasing technical challenge of drilling in complex environments and the use of Managed Pressure Drilling(MPD) techniques to control annular pressure for improved drilling performance in the oil industry has growing interest[1-4]. Understanding hole cleaning and controlling annular pressure in this complex environment is becoming increasingly important for a range of applications. The Virtual Well Engineer[VWE] has been identified as the engineering tool to address these issues in order to deliver a successful MPD operation. The VWE is the product name for a suite of well planning , monitoring and simulation packages with focus on Managed Pressure Drilling includng underbalanced drilling that allows the well engineering team to interact with virtual reality. Recent works initiated by the Well Engineering Group at The Robert Gordon University have extended the knowledge of multiphase flow in a drilling annulus through the tracking of the transient multiphase flow pattern prevailing and effects on hole cleaning , the pressure profiles and identification of hot spots in concentric and eccentric annular sections . The mechanistic models developed at RGU form the core algorithms for the VWE. This paper presents the architecture and functional capabilities of the VWE – HydraulicsDTS™ , which is used in simulating well operations.