PetroChina

China's largest oil and gas producer, operating within geological power law constraints where fewer than 40 supergiant oil fields originally contained approximately half of all discovered oil worldwide. Production heavily concentrated in Daqing Oil Field - China's largest, discovered 1959 with 16 billion barrels recoverable reserves.

Daqing still accounts for approximately 9% of China's daily oil output despite decades of production. Unlike Berkshire or Shiseido where concentration is strategic choice, PetroChina illustrates exogenous power law constraints - geology determines distribution. Strategy focuses on hunting for giants in exploration while maximizing recovery from proven giants.