Lessons Learned to Avoid Formation Damage Development During WasteSlurry Injection Operations

摘要

The injection of oil and gas wastes produced during the exploration and production phases have been provento be an effective technique toward achieving zero discharge.However,several challenges are associatedwith the injection of slurry into an underground formation.The most common challenge during waste slurryinjection(WSI)is the continuous loss of well injectivity due to poor engineering design of the injectionparameters for most of the current existing WSI wells.For the WSI operation,near wellbore formation damage(including the fracture damage)will be formedby the injected solids.The real time injection monitoring of the ongoing operations is important to correctany operational mistake and adjust the injection parameters in order to ensure the well longevity.The paper discusses the importance of injection monitoring and steps necessary to maintain the injectivityand perform a healthy WSI operation.Three different case studies are presented to highlight the operationalmistakes that caused a significant formation damage development in injectors in Eagle Ford,Haynesville,and Permian Basin shale plays.Certain guidelines depending on the monitoring results are provided inmodifying the slurry rheology,pressure,injection strategy etc.that are helpful in maintaining the injectivity.The presented case studies show that the wells with good monitoring program maintained its injectivityduring the course of its operation compared to the other wells that lost its injectivity sooner.The results from different case studies are used to prepare a set of guidelines that can be used to maintainthe well injectivity and extend the well life.This paper discusses the techniques that will help in eliminatingand avoiding the problems leading to formation damage and well plugging during the WSI operation.