Downhole pump and testing apparatus

摘要

The downhole pump of the present invention includes a piston housing with a plurality of piston assemblies disposed in the piston housing. Each piston assembly includes a piston reciprocatingly disposed in a cylinder. A valve body is connected to the piston housing and includes a plurality of inlet poppet assemblies disposed therein. One of the inlet poppet assemblies is located below and communicated with each of the cylinders for controlling a fluid intake to the cylinders. A plurality of outlet poppet assemblies is also disposed in the valve body. One of the outlet poppet assemblies is located below and communicates with each of the cylinders for controlling a fluid discharge from the cylinders. A master outlet check valve assembly is located below and communicates with all of the outlet poppet assemblies for preventing discharge fluid from flowing back to the outlet poppet assemblies. This master outlet check valve assembly includes a plurality of alternating annular sealing rings and annular separator rings disposed in a first annular cavity communicated with all of the outlet poppet assemblies.