Real-Time MPD Hydraulics Simulator: An Alternative Solution to the Conventional Pressure While Drilling Tool - A Case Study

Abstract

Narrow pore/stability pressure and fracture pressure margins (narrow operating window) can create severe complications during drilling operations. A slight change in the bottom hole pressure conditions can lead to significant Non-Productive Time (NPT) events like stuck pipe, fluid influx or lost circulation. In many cases, long wells with a narrow gap between pore/stability pressure and fracture pressure are impossible to drill with conventional practices because the annular friction pressure losses (difference between the dynamic and static pressure) are larger than the pore/fracture margin (Arnone & Vieira, 2009). Managed Pressure Drilling (MPD) enables operators to carefully balance between the pore and fracture pressure gradient by counteracting the lack of annular pressure losses (APL) when not circulating with the application of surface back pressure (SBP). MPD has the capability of providing a nearly constant bottomhole pressure with the proper compensation of pressure changes at surface. An accurate and real time determination of change in bottom hole pressure from dynamic effects is necessary to apply the correct SBP. This work investigates the accuracy of a novel approach in real-time MPD hydraulics modelling, which provides an alternative solution to the Pressure-While-Drilling (PWD) tool that measures the downhole annular pressure while drilling. The real-time hydraulics modelling proved to be accurate and allow for adjustments to be continuously made towards optimizing drilling efficiency, reliability, and safety without additional downhole tools.