I am considering what would be best. Either to study for an MBA (I plan on doing a PHD afterwards) or a PGD (i currently have an LLM). My preference is for a bias in oil and Gas, though i am a lawyer, i have worked in oil and gas for a number of years and would like to have qualification in the field. Please help..........

for a PhD, an MRes in the field you are interested in, is by far the best choice. Or an Mphil