A PULSED PHOTOACOUSTIC INSTRUMENT FOR THE DETECTION OF CRUDE-OIL CONCENTRATIONS IN PRODUCED WATER

The development of a pulsed photoacoustic instrument for the detection of crude oil concentrations in produced water is reported. The instru ment utilizes fiber-optic delivery of pulsed diode laser sources to an in-line sensor head, incorporating a gradient-index lens for optical delivery into the flow line and a piezoelectric transducer for acousti c detection. A crude oil concentration detection range of 5-8000 parts per million in water is demonstrated. The sensitivity of response was confirmed during preliminary field testing and is independent of vari ous interfering analytes, flow rate, and droplet size. (C) 1998 Americ an Institute of Physics. [S0034-6748(98)01111-3].