Injector or Producer wellDirectionType extWellDirectionType refinedWellDirectionType refinedExtWellDirectionType POSC 1.0 injector The well facility is injecting fluids into the subsurface. producer The well facility is producing fluids from the subsurface. huff-n-puff The well facility alternately injects (usually a steam or hot fluid) and produces. unknown It is not known which direction the fluids are flowing. uncertain The flow direction of the fluids is variable, but not on a regular basis as is the case with the huff-n-puff flow.