Study of pyrolysis characteristics and kinetics of oil-based drill cuttings

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 CO 2 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.