Abstract: An oilfield material reservoir is disclosed. The oilfield material reservoir has a body, the body having an upper end, a lower end, a sidewall extending between the upper and lower ends, the sidewall defining a recess within the body, an opening defined by the upper end, and a first orifice defined by the lower end. The oilfield material reservoir is also provided with a metering gate connected to the body at the lower end. The metering gate has a base having a second orifice aligned with the first orifice, and a knife gate connected to the base. The second orifice has a substantially trapezoidal shape. The knife gate is configured to slidably cover the second orifice. A method is also disclosed for controlling a discharge rate of oilfield material within the oilfield material reservoir by adjusting a metering open area of the second orifice according to mathematical modeling equations.

Abstract: An oilfield material reservoir is disclosed. The oilfield material reservoir has a body, the body having an upper end, a lower end, a sidewall extending between the upper and lower ends, the sidewall defining a recess within the body, an opening defined by the upper end, and a first orifice defined by the lower end. The oilfield material reservoir is also provided with a metering gate connected to the body at the lower end. The metering gate has a base having a second orifice aligned with the first orifice, and a knife gate connected to the base. The second orifice has a substantially trapezoidal shape. The knife gate is configured to slidably cover the second orifice. A method is also disclosed for controlling a discharge rate of oilfield material within the oilfield material reservoir by adjusting a metering open area of the second orifice according to mathematical modeling equations.

Abstract: A multi-tank system for preparing fluids for hydraulic fracturing of reservoirs and methods of injecting the prepared fluid upstream from pumping units are disclosed. The multi-tank system allows for a proppant slurry to be continuously formed and mixed with a proppant carrier in staggered phases to form a fracturing fluid. This fracturing fluid can then be injected into the reservoir at normal injection pressures, thus reducing wear and downtime on the blender, and allowing continuous flow of proppant.

Abstract: A mixing unit comprising a frame, a rheology control portion, and a high-volume solids blending portion. The rheology control portion comprises means for receiving a first material from a first transfer mechanism, a dispersing/mixing system connected with the frame, and a first metering system to meter the first material from the first material receiving means to the dispersing/mixing system. The dispersing/mixing system disperses/mixes the metered first material with a fluid to form a first fluid mixture. The high-volume solids blending portion comprises means for receiving a second material from a second transfer mechanism, a solids blending system connected with the frame, and a second metering system to meter the second material from the second material receiving means to the solids blending system. The solids blending system blends the metered second material with the first fluid mixture to form a second fluid mixture.