In April 2020, PrJSC MC Ukrnaftoburinnya successfully completed the workover of well #35 at the Sakhalin field. The workover was performed without killing the well using a hydraulic snubbing unit. The tubing lift was replaced with gas-tight chrome-plated tubing, which will extend the well's trouble-free operation for at least 4 years.

The work was performed using the latest RDE-340K supply unit, manufactured in 2019, with a lifting capacity of 180 tons. Among the advantages of the unit is the ability to work at the wellhead at a static pressure of more than 350 atm. The contractors were Denimex Workover Solutions LLC, Weatherford Ukraine LLC, and Geo Well Services LLC.

The use of snubbing technology made it possible to avoid a decrease in well production rate, which usually occurs in the case of traditional workovers with well killing, and to extend the workover period. The workover was completed in 13.5 days. The initial daily flow rate after the workover was 200 thousand m3 of gas and 6.7 tons of condensate.

"Despite the challenging times for the industry, UNB continues to invest in modern technologies to improve the efficiency of the field development, maintain and increase production rates. Our team is not resting on its laurels and is considering the possibility of performing workovers using a coiled tubing unit at other wells in the Sakhalin field in the near future."

- said Bogdan Kukura, Technical Director of PrJSC MC Ukrnaftoburinnya.