On-line determination of the water cut and chlorine impurities in crude oil using a pulsed beam of fast neutrons

A neutron-based sensor has been developed able to measure the water cut and the chlorine content in crude oil. The sensor is based upon the use of a pulsed fast neutron source. Two different cases were studied. Case ‘‘A’’: chlorine detection with no water present and case ‘‘B’’: water cut measurements with no chlorine present. The minimum detection limits for case A and case B were found to be (62 ± 6) mg/L and (2 ± 2) vol%, respectively. •A neutron sensor for on-line determination of water-cut and chlorine impurities in crude oil was developed.•Measurements were done on geological samples taken from Croatian oilfields and on standard samples prepared in the laboratory.•Since both chlorine and oxygen have similar gamma-ray lines at 6.1 MeV, these two were separated by choosing a different pulsing frequency for the neutron beam.•A similar setup (neutron probe) could be easily made for monitoring individual wells.