Abstract: A method is for processing fluid from at least one well. A related apparatus has at least one separator which is arranged to receive production fluid from the well downstream from at least one wellhead. The separator is used to remove solids from the production fluid, to produce a cleaned fluid which travels downstream on a flow path from the separator through either or both of: a Christmas tree on the wellhead from which the separator receives the fluid; and a Christmas tree on another wellhead.

Abstract: An assembly is for an oil and gas production platform or rig and related methods. The platform or rig may have a Christmas tree deck and a hatch deck above the Christmas tree deck. The assembly may have a Christmas tree connected to a top of a wellhead on the platform or rig located at the Christmas tree deck. The assembly may further have a processing unit comprising at least one separator, positioned above and connected onto a top of the Christmas tree. The Christmas tree may bear at least partially the weight of said separator. The separator may be operable for receiving production fluid from at least one oil and gas production well and removing solids to clean the production fluid.