Turkey kept her mouth shut during the crisis of Ukraine, and did not criticize Russia, even though Turkey could have used the issue of the Crimean Tatars to attack Russia. The Crimean Tatars are of Turkic origin and are oppressed by the Russians. Ukraine is not very important for Turkey’s energy policy, and it was actually a positive thing for Turkey’s energy policy that Shell and Chevron had to abandon Ukraine for security reasons.
Map Shell and Chevron in Ukraine
But after the Russian-Turkish confrontation over Syria, the Turks agreed to cooperate with the Ukrainians in the Black Sea, and also to jointly manufacture military equipment.
See also “Shell and Chevron to Leave Ukraine”
“Ukraine, Turkey Agree to Ramp Up Military Cooperation in Black Sea”, January 2016
“Crimean Tatars Feel Abandoned by Turkey”, November 2014