Real-Time Measurement of Eccentricity in Primary Cementing of Oil and Gas Wells

Abstract

We propose a new method to measure eccentricity of the annulus in real-time during primary cementing. Our methodology is based on seeding the displacing fluids with neutrally buoyant particles. The process of seeding can happen by a specially designed bottom plug that releases a particle every few seconds. Particles at different azimuthal position experience a different axial velocity, because of the eccentricity of annulus. We infer the local velocity of the fluids by tracking the trajectories of particles and correlate it to the local eccentricity of the annulus. We show that this methodology allows us to find an axial profile of eccentricity along the well, and helps to identify geometrical irregularities, such as washouts, along the annulus.