Evaluation of the effect of temperature and pressure on the process of combating loss of circulation using fibrous and granular materials

Abstract

This study aimed to evaluate the influence of pressure and temperature in combating the loss of circulation, using granular and fibrous materials in different techniques of mitigation. Experimental studies were performed using water-based fluids containing polymers as viscosifiers and lost-circulation materials (LCM). Two kinds of tests were done in static and dynamic conditions. In the static approach, the filtration and fracture sealing tests were performed in a 2 mm slot fracture in High-Temperature/High-Pressure (HTHP) filtration cell. For the dynamic approach, two Fracture Flow Simulators (FFS) were used. A FFS 1.0 operated under low pressure and ambient temperature which allowed the visualization of the fluid flow and the structure of the forming seal. In the FFS 2.0, the tests were applied in cases of high pressure and high temperature. Based on the test results, it was possible to identify the sealing mechanisms in dynamic and static approaches where the studied suspensions and kinds of LCM proved to be efficient in sealing fractures dynamically. The data obtained from the simulators were used to analyze the behavior and allow to phenomenologically evaluate the different mechanisms of action of LCM and even the most efficient blends of materials. The studies of the effect of temperature, pressure, and composition of granular and fibrous materials and a blend of them in the combat of loss of circulation showed that the temperature had a more significant effect on the volume of fluid lost. It was found that the optimized blend composition was made of 75% granular and 25% fibrous materials allowing those materials to be applied more efficiently in combating loss of circulation.