By Jan Strupczewski BRUSSELS (Reuters) – EU countries have reached agreement on their sixth package of sanctions against Russia over its invasion of Ukraine, including a complete import ban on all Russian seaborne crude oil and petroleum products in six to eight months. Below are the main elements of the package: OIL EMBARGO The EU will stop buying all Russian crude oil delivered by sea – or 2/3 of all EU imports of Russian crude – from early December, and will ban all Russian refined products two months later. Deliveries of Russian crude via the Druzhba pipeline, which runs through Poland, Ge…