Abstract
Hydraulic tubing anchors, similar to the traditional mechanical tubing anchor (TAC), have been around for over 30 years. Unlike the TAC, the hydraulic tubing anchor does not require surface manipulation to set. Differential pressure between the tubing and casing anulus engages the anchor to the casing by way of a hydraulic piston. Technology and materials have greatly improved in recent years resulting in a vast improvement in reliability of this particular tool. To better understand the dynamics of hydraulic anchors, a test rig was constructed to approximate down-hole conditions in terms of depth and holding capacity. The test assembly allows for controlling the perceived depth by way of pressurizing the tubing, or internal bore of the hydraulic anchor. Varying the pressure in the "tubing" simulates the pressures seen at any depth. The holding capacity of the anchor is tested by a hydraulic jack, which is placed under the anchor. The jack, having a known bore, can easily correlate PSI to lifting force placed on the anchor. Numerous tests were conducted at varying depths to find the lifting force required to dislodge, or cause the anchor to slip. Anchor test data as well as analysis of the interface between the anchor and casing are presented.
