Simulation of a Multiphase Flow Sampling System

Measuring the production rate of oil, brine, and gas throughout the life of a well is essential for reservoir management optimization and early detection of water or gas breakthroughs. However, the measurement of phase flow rates in a multiphase flow is difficult. Most metering technologies are subject to errors due to slip between the phases and changes in flow regime. A new approach was proposed to periodically sample the whole flow for a short time while controlling the pipeline pressure so that the sampling action does not change the phase flow rates. To study the feasibility of this approach, a state-space model of the fluid pipeline coupled to the sampling system was developed in MATLAB^®. Simulink^® was used to model the system dynamics and determine whether the forces and response times required from actuators were achievable. Promising simulation results were followed by construction and testing of a prototype meter in a flow loop, where the actual system dynamics were confirmed to be well predicted by the simulation.