Summary: Composite screens are a critical component of drilling fluid shale shakers, and their performance directly affects the recovery efficiency of drilling fluid. This study focuses on the composite screens of shale shakers and simulates the flow of non-Newtonian drilling fluids through different structures of composite screens to investigate the impact of drilling fluid rheological parameters and screen compositions on screening performance. The research results indicate that the flow velocity of the drilling fluid is the highest while passing through the lower screen, and the turbulent kinetic energy (TKE) is at its maximum in the lower screen area, where energy dissipation is also the greatest. An increase in the rheological parameters of the four-parameter model drilling fluid generally increases the difficulty of passing through the screen, with the flow behavior index and viscosity coefficient having a particularly significant impact on the pressure drop coefficient. Compared with the plain composite screen, the herringbone composite screen and plain patterned composite screen have lower pressure drop coefficients, with the herringbone composite screen demonstrating the best screening performance. These findings provide theoretical references for flow analysis and structural optimization of shale shaker screens in drilling fluid applications.
In situ shale oil extraction is an efficient and environmentally friendly development method. This article employs in situ extraction technology to heat shale oil, optimizing its high-temperature gas parameters based on indicators such as cumulative oil production rate and cumulative power consumption in the shale oil region. Using the optimized high-temperature gas parameters, an exploration of shale oil with different thicknesses was conducted. The results indicate that out of nine different high-temperature gas parameters, five cannot induce complete fracturing in the shale oil region. Models II, III, I, and IV each reach the onset of shale oil fracturing in the entire region after 870, 900, 1020, and 1080 days, respectively. The heating rate factor peaks at 1620, 1620, 1800, and 1980 days, with values of 0.277, 0.305, 0.317, and 0.32, respectively. Compared to Model II, the peak of the heating rate factor in Model I is the highest, showing an increase of 15.52%. Among these models, Model I has the lowest unit volume power consumption at 1063.41 kW/m3. The unit volume power consumption in Model I exhibits the most significant reduction, with a maximum decrease of 16.45% compared to the other three shale oil models of different thicknesses. The research results provide a basis for the engineering development of shale oil.