Maximising Operational Efficiencies and Reducing Well Cost Through Effective Drilling Waste Management Solutions

Abstract

Abstract Drilling at remote sites, such as artificial islands, comes with challenges, not least of which is drilling waste management. Drill cuttings, generated from the wellbore during drilling, are traditionally the focus of attention and a solution is available to treat this waste stream at source. However, in many projects slop waste and, in some cases, conductor drilling waste is also generated. Until now, no one process has been able to treat these two additional waste streams at source. Adopting traditional waste treatment methods for these waste streams at a remote site could increase project overheads by more than 200%, versus a conventional well site location. Therefore, it is important to maximise efficiencies when it comes to recycling all drilling waste streams, recovering value and reducing disposal requirements at remote sites. This paper outlines how a single process using modular equipment, originally deployed to process drill cuttings, has now been developed to deal with all three key waste streams. The process was developed when a major operator in the United Arab Emirates (UAE) required a solution for the treatment of conductor drilling waste produced at one of the region's largest fields at an artificial island complex. The ground-breaking solution developed allows for conductor drilling waste, created by a piling rig, and legacy slop stored at the location for nearly seven years, to be treated on site using a single process. This was done in addition to day-to-day drilling waste management, resulting in economic, operational, safety and environmental benefits. This achievement was primarily through the identification by TWMA of capacity within its thermal drilling waste treatment technology to eliminate the waste streams generated at source. Opening the operating window of the technology eliminated significant haul-off costs, reduced emissions and health, safety and environmental (HSE) risk and improved operational efficiency. The new strategy was implemented in 2019. Since then, the solution has successfully dealt with a legacy waste stream amounting to seven years' worth or 13,500 MT of conductor drilling waste and 40,000 bbl of stored slop waste, in addition to ongoing drill cuttings treatment. Removing both of these waste streams has achieved significant operational, safety and environmental savings including: the elimination of onshore transportation, processing and landfill costs, elimination of island services and storage, a significant reduction in skip lifting operations and waste handling, a reduction in manpower requirements due to use of existing equipment and personnel, and a reduction of risk to the environment posed by the storage of the waste streams. The operator now also has significantly more land area available for other purposes. By processing at source, clear tangible savings have been achieved in all areas of the operation. This strategy allowed the operator to set new standards with regards to drilling waste management in the UAE. It has also driven a discussion globally about how to deal with multiple waste streams by opening the operating window of existing single-process systems instead of requiring additional processing equipment.