Change Industrial Automation for Oil & Gas Sector Career.

Hi,
I am working in Engineering and design for DCS/ESD/PLC/F&G systems, RTU/SCADA system. It is industrial automation for oil & Gas sector.
I feel that there are not much scope in the same field because reception in Oil & Gas Sector. So I have decided I want to change my profile and job.
Could you please suggest filed, which is best suited to me. My preference in automation testing.