To safely plan and execute MPD Influx Control operations, the limits of the primary barrier envelope must be communicated and understood. These safe operating limits have historically been represented with an MPD Operations Matrix. More recently, the development of the Influx Management Envelope (IME) has provided a means of communicating the primary barrier limits with improved accuracy and clarity. However, the generation of the IME currently requires performing a series of complex well control simulations with specialist engineering support. Because drilling operations are dynamic in nature, a practical method to generate the IME boundaries at the wellsite is required so that changes to mud weight, flowrate, surface and bottom hole circulating temperatures, trajectory, and bit depth can be accounted for, and the IME kept up to date.
This paper describes the development of a novel tool to quickly and automatically generate IMEs at the wellsite without the need for sophisticated modelling software and specialist personnel. The single bubble derivation that was originally presented by Culen et al was analysed further to obtain a more accurate and explicit relationship rather than an implicit one, which forms the basis for the calculations. The IME can be updated based on any well parameter changes, which allows field engineers to maintain an up to date and accurate IME throughout MPD operations.