Eccentric wellhead hydraulic drive unit

Abstract

A wellhead hydraulic drive unit to operate various styles of downhole pumps, the wellhead hydraulic drive unit comprising: an hydraulic cylinder having a piston positioned therein for reciprocation within the cylinder, hydraulic fluid supply means for producing reciprocation of the piston, a ram within the cylinder and operably connected to the piston, the ram having a bore, and production tubing inserted through the bore of the ram for enabling well fluid to be discharged from the well, wherein the hydraulic fluid supply means are radially offset within the cylinder and the ram is oppositely radially offset within the cylinder. Offsetting the hydraulic fluid supply means and the ram allows for a larger inside diameter in both the production tubing and ram, increases the sizes of downhole pumps which can be installed/removed without removal of the drive unit, and serves as an anti-rotational feature with regards to the piston and ram.

Dependencies are inferred from the claim text.