Abstract: A sand separator for capturing solid debris from oil and gas wells includes a spherical, high-pressure vessel adapted to couple downstream of a wellhead. Fluid entering the separator follows a helical path around a vertical separator axis, slowing and separating into water, gas, oil and solid debris, the latter sinking to the bottom. A conical, downwardly opening flue descends from an exit port at the top and terminates in a horizontal, coaxial perimeter. A scalloped, annular collar inside the flue perimeter creates a low barrier to fluid flow into the flue. As fluid constituents circulate toward the flue, they recombine free of sand and rock debris, pass under the flue perimeter and across the collar, slowing further and becoming substantially laminar A fluid dome rises inside the flue with a gas layer above other fluid constituents, permitting the gas to exit the separator through the exit port.

Abstract: A sand separator for capturing sand and rock debris from recovered natural gas fracturing fluid includes a cylindrical, high-pressure-rated vessel disposed vertically and immediately downstream of the gas wellhead. High pressure fracturing fluid enters the top of the separator into an inner flue extending coaxially downward to terminate a spaced distance above the bottom of the vessel. Transverse baffles spaced apart along the length of the flue extend through the flue to the inner walls of the vessel to keep the flue centered within the separator. As the fluid enters the separator, openings through the flue near the vessel inlet permit lighter weight and gaseous constituents to escape the fluid and bypass the flue, thereby reducing the velocity of the fluid remaining inside the flue. As the remaining fluid falls to the bottom of the vessel, it further slows as it reverses direction to rise between the flue and the vessel walls.