Patent ID: 9151141
Filing Date: 2015-10-06
Classification: E21B

Abstract:
1. In a fluid producing well in which a subsurface pump is actuated by an actuation string extending to the subsurface pump, said pump lifting fluid from the subsurface to a higher elevation through a tubing string having an interior and an exterior, said fluid producing a hydrostatic pressure inside the tubing string, an apparatus for changing loading in the actuation string, the apparatus comprising: a. an upper plunger slideably disposed inside an upper barrel, the upper plunger having a first axial opening extending through an upper interior; b. a lower plunger slideably disposed inside a lower barrel, the lower barrel having an interior and an exterior, the lower plunger having a second axial opening extending therethrough, wherein the upper barrel and the lower barrel are connected together by an intermediate connector to comprise a tube member, the tube member made up as a component of the tubing string; c. said lower barrel having a different cross-sectional area than said upper barrel; d. a fluid communication means in the intermediate connector which allows fluid communication from the interior of the lower barrel to the exterior of the tubing string; and e. the actuation string extending through and below the upper plunger and the lower plunger to operate the subsurface pump which is set below the lower plunger.