(1) Chevron Research has been developing an oil shale retorting concept called the staged turbulent bed (STB) retort. This process handles a broad size distribution of small particles. Separate vessels are used for retorting and combustion. Hot combusted shale is recycled to the retort to supply the necessary process heat. (2) The process has been studied using a 1 ton/day fully integrated pilot plant. Scale-up has been studied by physical modeling on a scale-up to 350 ton/day. Process operating characteristics and product qualities from pilot operation are discussed. Plans for futher development of the STB oil shale retort are reviewed. 14 refs.