Sinopec Sichuan Petroleum Branch is a sales company and a pioneering sales company (ask people who want to know, what is an out-of-area company? Sichuan is an outside company of Sinopec).
Changqing Oilfield, in Sichuan, may be a pipeline company, which is the business of transporting natural gas from west to east.
Different positions, different treatment, as for the new front-line employees, if you are a graduate of Petroleum Institute, you should choose the corresponding professional company. If your major is not right, it is recommended to go to the sales company to find a major unrelated to petroleum major.
If you are an office, I suggest selling the company. Challenging, the company is generally young, there is room for promotion, and the sales company shows its ability. Changqing Oilfield is an old enterprise for nearly 20 years, paying attention to background education, professional title and length of service.
Good luck!