Advanced Computational Modeling for Estimating Safe Cuttings Load Through MPD Surface Equipment
Kedar Deshpande; Pravin Naphade; Chad Wuest
SPE - Society of Petroleum Engineers
June 4, 2021
IADC/SPE Asia Pacific Drilling Technology Conference, June 8–9, 2021
The critical components of Managed Pressure Drilling (MPD) operations include surface manifold, surface chokes and the pipes connected to Mud Gas separators. The MPD surface equipment needs to safely handle a multiphase mixture of drilling mud, cuttings load and reservoir fluid influx during operations. The focus of this work is to establish safe cuttings load limit that can be handled by MPD system using advanced computational fluid dynamics (CFD) modeling approach.
In MPD operations the surface choke is the key surface manifold component through which the fluid and cuttings flow before entering the Coriolis meter. Based on choke position only a certain volume and size of cuttings (cuttings load) can pass through chokes without causing unintentional pressure surges. In this work, Non-Newtonian fluid flow using Eulerian-Granular modeling approach is presented to understand the effects of cuttings load and different choke positions on the overall pressure drop through MPD surface manifold. Several CFD studies were conducted for different choke sizes, cuttings load and fluid properties to understand velocity profiles, cuttings accumulation and pressure drop across the MPD surface manifold.
CFD results were first validated with available test data to generate confidence in CFD simulation model settings, good match was observed in pressure values between test and numerical results. Based on CFD simulations, charts were developed showing effect of operational parameters that help field personnel design the best surface equipment configuration, determine associated pressure drop and guard against the possibility of Non-Productive Time (NPT). CFD studies provided insights into cuttings accumulation and associated pressure drop change across choke for given operating conditions.
Usage of advanced computational methods helped model the multi-phase flow with cuttings accurately and provided safe cuttings load estimation for given range of operational parameters.