Sludge interface measurement in the storage tank utilizing neutron backscattering technique: A field experiment

Modern industrial plant operations commonly necessitate a measurement system of the liquids level interface in the oil storage tank. Various advanced-level indicators almost meet the demand, but these may not be in online condition and are less accurate due to sedimentation in the bottom tank. Sedimentation or sludge known as a petroleum hydrocarbons complex emulsion, contained water and solid particles generated during distribution, storage, or even production. The neutron backscatter technique can help the maintenance system of the tank or vessel by measuring sludge levels from outside the wall. This paper presents a non-intrusive method for identifying the interface between two materials in the crude oil storage system. A fast neutron source (241Am–Be) with activity 1 Ci (Ci) and a portable backscattering neutron detector are used for storage tank measurement. The storage tank has an outer diameter (OD) of 34 m and a height of 11 m. Time measurement is 2 s for each position, starting from 0 m to 11 m. The slow neutron intensity can be correlated to the hydrogen concentration inside chemical compounds. The interface between sludge and oil is identified at 27 cm from the bottom plate. The method has the potential for non-destructive measurement of sludge in a refinery facility.