我已在中国石油大庆石化公司工作两年了（用英语怎么说）？

I have worked for two years in the Chinese Petroleum Daqing Petrochemical Company .

I've been working in Da Qing Petroleum and Chemical Industry Company of China Petro for two years.

I've been working in PetroChina Daqing Petrochemical Company for two years.

中国石油大庆石化公司的正确英文翻译是PetroChina Daqing Petrochemical Company