New wells were initially cleaned-up directly to the Plant Facilities in Tengiz. The existing facilities were not designed to process well flowback fluids which can contain contaminants, emulsions and solids from drilling and completion fluids. Well flowback operations directly to the process facilities were causing plant upsets and a backlog of wells to be placed on production.
An MRM (Management of Residual Materials) spread was introduced in TCO (Tengizchevroil) in 2016 to clean-up new wells prior to performing a Plant flowback. The MRM unit utilizes an EverGreen Burner that performs fallout free and smokeless combustion of liquid hydrocarbons and residual well materials during well clean-ups.
Cleaning-up new wells using the MRM spread has significantly improved the number of successful Plant flowbacks per year, lessons learned in all phases have been captured and will be shared. However, MRM clean-ups did not always guarantee a problem-free Plant flowback since only qualitative methods were being used to determine when a well had been cleaned-up sufficiently to be routed to the Plant.
To improve the ability to determine a well's readiness for a Plant flowback, new quantitative methods were developed which include continuous sampling and gas-chromatography analysis along with compatibility tests.
This paper will share the best practices and challenges during MRM operations, research details, field trial and results that were achieved after optimization of the flowback process.