In this context, "basic engineering", which is also called "front-end designing", is translated into Russian as "bazovoye proektirovaniye". Basic engineering (=front-end designing) is the first stage in the designing process of a facility. Once the front-end design is accepted by the company, a detailed design (=rabochiy proyekt) is prepared by the engineering company. Once the detailed design is approved and the financing is available, the construction process starts. "Bazovoye proektivoraniye" and "Bazoviy proekt", as well as "Rabochee proektirovaniye" and "Rabochiy proekt" are perfectly understood by Russian engineers, because they are the accepted terms.

Hope that this helps,

Best regards,

Artyan