Abstract: A change-out flange suited for use at an existing head casing of an oil or gas production well. The change-out flange is devised to replace standard hammer caps atop a well casing. By the present invention, with comparative ease a variety of wellhead equipment can be removably and interchangeably secured to the wellhead using an existing casing bowl or spool. The change-out flange has a casing hub that can be screwed unto a known casing bowl, and an integral connection flange provided with a plurality of connection holes arrayed in a manner consistent with the connection hole arrays of an assortment of conventional wellhead devices such as valves. A variety of well head devices thus can be more readily removed from, and securely replaced upon, the change-out flange. Lockdown pins are insertable into the change-out flange in a manner which secures the tubing hanger in place within the casing bowl.

Abstract: A lubricator for use at a wellhead such as an oil or natural gas well. The lubricator has a polished rod on which an item, such as a back pressure valve, may be disposed for placement, for example to isolate the wellhead from the well pressure to permit wellhead servicing. The rod is moved by hydraulic power, rather than manually. A piston is connected to the polished rod within the lubricator barrel. Hydraulic pressure within the barrel, above or below the piston, is controlled to cause the rod to move up and down, under power, to permit the rod and items thereon to be lowered and retrieved.