I noticed four access points. I think it's only for blue bloods. The only access point I can think of worth trying is by going off road on the coast via the telecoms tower station south of Simaisma town.
Your other bet would be through the north of the Pearl leading to the Emir's island. (Construction & Development area?).
The other two access points are fenced and gated - Lusail and another one just south of the abandoned petrol station on the northbound 1A AlKhor highway.
Good luck.