They have the resources to make their own insurance company.
The question is, will this company be recognized by all required players (ports, authorities etc.). If you're insuring something worth hundreds of millions of dollars, you really want the insurance company to meet certain standards, and have a good reputation of paying out. Can Russian achieve that? Probably. Can they do it quickly? That sounds much trickier.
If Russia doesn't back its insurance it loses credibility around the world.
Russia is a major player in the oil world. It has the relationships and experience to manage this.