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In this manuscript, the samples were collected from Weiyuan Investment Group. The basic properties of the oil-based drill cuttings and their pyrolysates were analyzed. The results show that the oil content of the oil-based drilling cuttings is 7.87%, and the average calorific value of pyrolysis gas is about 20,327 kJ m−3. In the component of gas, hydrogen accounts for 30.64% and CO2 accounts for 43.34%. The main components of pyrolytic oil are diesel fraction, of which the H/C ratio is 1.90 and the linear alkane is the main component, accounting for 65.65%. And the carbon number of the pyrolytic oil is mainly distributed in C12~C25. The pyrolytic products possess high value of recycling. The pyrolysis kinetics of oil-based drilling cuttings was studied by developing different kinetic models. Firstly, the mass loss of oil-based drilling cuttings can be divided into two stages. The first stage consists of the evaporation of water and the volatilization of small molecular organic compounds. The second stage is the main pyrolysis process which contents the breaking of carbon–carbon bond, and the thermogravimetric curve shifts to the high temperature region with the increasing of heating rate. The calculated results of different kinetic models show that the fitting degree of the two models is high. According to the calculated results using Friedman model, the pyrolysis stage of oil-based drilling cuttings increases from about 73 kJ mol−1 to about 109 kJ mol−1. According to the calculated results using DAEM model, the activation energy increased from about 63 kJ mol−1 to about 80 kJ mol−1. The results can help provide experimental data for industrial processing of oil-based drilling cuttings in Weiyuan Investment Group. [ABSTRACT FROM AUTHOR]

The water-lubricated thrust bearings of the marine Rim-Driven Thruster (RDT) are usually composed of polymer composites, which are prone to serious wear under harsh working conditions. Ultrasonic is an excellent non-destructive monitoring technology, but polymer materials are characterized by viscoelasticity, heterogeneity, and large acoustic attenuation, making it challenging to extract ultrasonic echo signals. Therefore, this paper proposes a wear monitoring method based on an improved ultrasonic reflection coefficient amplitude spectrum, introducing an ultrasonic transfer function to mathematically resolve the attenuation coefficients in the propagation model, and using a differential evolutionary algorithm to invert the thickness, sound velocity, density, and attenuation coefficients of polymer bearings simultaneously. The effects of different influencing factors on the ultrasonic signal and identification results are explored, including probe contact pressure, surface roughness and surface inclination; In order to remove the influence of water film overlap on the identification of polymer bearing thickness, a water film separation method based on time-frequency domain ultrasonic reconfiguration is proposed to construct the ultrasonic theoretical time domain waveform of the bearing. An ultrasonic wear measurement system is built to record the ultrasonic echoes of PEEK test blocks with different pressures to the probe, surface roughness, and tilt angles. The experiment is carried out on the water film calibration test rig, using a high-precision spiral micrometer to simulate the mixing of water films of different thicknesses with polymer test block and collecting ultrasonic signals. The results show that the method has a thickness identification error of approximately 0.5% for PEEK specimens with different probe contact pressure, roughness, and tilt angle, and the reconfiguration thickness identification error is less than 1% for the full range of water film overlap. • Propose a wear monitoring method based on an improved ultrasonic reflection coefficient amplitude spectrum, introducing an ultrasonic transfer function to mathematically resolve the attenuation coefficients in the propagation model. • A water film separation method based on time-frequency domain ultrasonic reconfiguration is proposed to construct the ultrasonic theoretical time domain waveform of the bearing. • Use a differential evolutionary algorithm to invert the thickness, sound velocity, density, and attenuation coefficients of polymer bearings simultaneously. • The method has a thickness identification error of approximately 0.5% for PEEK specimens with different probe contact pressure, roughness, and tilt angle, and the reconfiguration thickness identification error is less than 1% for the full range of water film overlap. [ABSTRACT FROM AUTHOR]