First Application in Russia of Bright Water™ Chemical for Waterflood Sweep Improvement in the Samotlor Field

The first pilot in Russia of Bright Water™ chemical (Thermally-Activated Particles or TAP) for improving waterflood sweep has been commenced in the Ust Vakh Satellite to the giant Samotlor Field in West Siberia in 2011. This field (the sixth largest in the world) has been under development since 1969. Water injection commenced in the early 1970s, and many wells now have very high watercut. However, large volumes of oil remain unrecovered in multiple reservoirs, and reservoir heterogeneity can have a significant impact on oil recovery by reducing reservoir sweep efficiency of the waterflood. A screening process was used to select the most suitable pilot candidate areas from a number of different fields which could potentially benefit from the technology. The Ust Vakh Satellite is a more recent development since early 2000s and possesses multiple wells completed in only a single zone, which is advantageous for pilot interpretation. Five wells in the Ust Vakh Satellite were selected on the basis of the number of good injectors, the presence of reservoir heterogeneity and high Water Oil Ratio wells despite the relatively short time under waterflood in this location. Another key criterion was selecting an area at the edge of the field with lowest interference possible in order to decrease the risk to interpreting a production response during the pilot. Tracer was injected in all wells prior to treatment which confirmed the lack of any high-rate fracture connectivity from the injectors to offset producers and validated the treatment design. The 5 wells were treated with a total of more than 400 tonnes of TAP over a period of 23 days. This paper describes aspects of candidate screening, treatment design, surveillance, implementation of the pilot and early response from the treatment. Note - Bright Water™ is a trademark of Nalco Company