: The petroleum industry is facing challenges in terms of cost, safety and environmental regulations. The demand for energy is ever increasing. The crude oil exploration and refining contribute major part of economy. Increased industrialization calls for more efficient methods for oil exploration, petroleum refining and re-refining. Many times, the oil exploration and consumption is deciding factor for growth. Various aspects such as catalyst cracking, sludge handling, gas recovery are being studied for optimization and effluent management. Many investigators have carried out investigations on these aspects. It is very important to have effective methods for the optimization of the reactions carried out in these industries. The increased cost and depleting resources highlight the need for enhanced oil recovery. Material substances, processes or circumstances which pose threat to health and well being of workers in any occupation are termed as occupational hazards. The present review provides brief insight into research and studies of these key aspects of petroleum and refining engineering.