Ingenious Solutions for Well Cleaning Applying Environmental Engineering

Abstract

Abstract Cleaning of offshore wells prior to completion operations has previously been associated with a relatively high instant environmental impact. Even though there has been an improvement of the environmental profiles of the chemicals used in well cleaning operations over the past years the discharges of fluids during well cleaning operations has not been significantly reduced. The most common solution has been to have enough storage capacity to collect the volumes of spent fluids offshore and thereafter send the fluids onshore for waste treatment or re-inject the fluids into the subsurface formation. This paper describes a well cleaning system designed to meet the requirements for reduced environmental impact. This has been achieved by applying environmental engineering as a positive aid in the design process identifying the opportunities instead of focusing on the restrictions. The main parameters in the well cleaning design are based on a reduction in discharges, re-use and recovery of fluids, albeit an improvement of the environmental profiles of the chemicals is still very important. The reduction in discharges is achieved by modifying procedures, equipment and chemicals. The paper focuses upon how to obtain an improved well cleaning fluid based on technical and chemical modifications which allow for re-use and recovery of the fluids at the same time as the fluids have their desired well cleaning effects. The improvement this system represents related to environmental impact, has been verified in both laboratory tests and field experiences, and will be presented in the paper.