F-Visa Double Entry to Multiple Entry

I'm a Dutch (Netherlands) student living in Shenzhen with an F double entry (duration of 90 days), however for my internship (and travel) I will also be required to travel back and forth between the Hong Kong Office from time to time, now my question. Am I able to change my F double entry to multiple entry inside shenzhen or hong kong? I will leave back for my home country at the end of June.

Thanks in advance.