Study on Pyrolysis of Shale Gas Oil-Based Drilling Cuttings: Kinetics, Process Parameters, and Product Yield

Abstract

The main reaction range (350–550 °C) of oil-based drilling cutting (OBDC) pyrolysis was studied by a thermogravimetric analyzer and a vacuum tube furnace. The average activation energies calculated by four model-free methods were 185.5 kJ/mol (FM), 184.16 kJ/mol (FWO), 166.17 kJ/mol (KAS), and 176.03 kJ/mol (Starink). The reaction mechanism was predicted by the Criado (Z-master plot) method. It is found that a high heating rate is helpful to predict the reaction mechanism, but it cannot be described by a single reaction model. Under the conditions of target temperature higher than 350 °C, residence time higher than 50 min, laying thickness less than 20 mm, and heating rate lower than 15 °C, the residual oil content is lower than 0.3% and the recovery rate of mineral oil is higher than 98.43%. Solid phase products accounted for more than 70%, reached the maximum 17.04% at 450 °C, and then decreased to 15.87% at 500 °C. Aromatic hydrocarbons, as coking precursors, are transformed from a low ring to a high ring. Recycled mineral oil can reconfigure oil-based mud (OBM). The research results can provide a theoretical basis for process optimization.

Study on pyrolysis law of shale gas oil-based drilling cuttings : kinetics and product characteristics

“…This indicates that oil can be used as a substitute for diesel fuel. [35,36]。 However, the content of halogenated hydrocarbons increased further during the hightemperature treatment. The content of monocyclic aromatic hydrocarbons decreased, and the types of polycyclic aromatic hydrocarbons further increased, but the percentage increase was not obvious.…”

Construction of Shale Gas Oil-Based Drilling Cuttings Degrading Bacterial Consortium and Their Degradation Characteristics

“…According to China, it generates over 4 × 10 5 m 3 of OBDCs annually [ 2 ], with the Fuling shale gas region in Chongqing alone producing as much as 4 million tons annually [ 3 ]. Generally, they are characterized by petroleum hydrocarbons, heavy metals, and alkaline salts, leading to their classification as hazardous waste [ 4 , 5 ]. Therefore, effective disposal has emerged as a shared concern among countries involved in shale gas development.…”