Laboratory evaluation of rock-based geopolymers for zonal isolation and permanent P&A applications

Abstract

In this work, we have studied selected rheological properties and mechanical properties of rock-based geopolymers. The geopolymers are suggested for zonal isolation and permanent abandonment of hydrocarbon wells. Our viscosity measurements of the geopolymeric slurries shows a very small yield stress and a nearly constant additional viscosity. To find the effect of mechanical vibration, a rotational viscometer was modified by being equipped with a mechanical vibrator. Consistency of the geopolymeric slurry was measured by utilization of atmospheric and pressurized consistometers to find the impact of pressure and temperature on pumpability. The downhole temperature uncertainty was also studied by using atmospheric consistometers. Static-fluid-loss is an issue, which causes loss of hydrostatic pressure. Therefore, static-fluid-loss test was carried out. Strength development of the geopolymeric slurry was measured directly and indirectly by utilization of uniaxial compressive strength and Ultrasonic Cement Analyzers, respectively. As the pre-defined algorithm could not convert the sonic velocity to sonic strength, a custom algorithm was generated. The elastic shear wave and compressional wave velocities and velocity anisotropies of the samples were tried to be determined experimentally. The measurements were conducted on cube-shaped specimens in a triaxial multi-anvil press using the ultrasonic pulse-transmission technique. As it is necessary to study the bond strength between the geopolymers and pipe, steel pipe was used. The shear bond strength between pipe and the rock-based geopolymer was measured.