Publications

Well XA-02 is an offshore oil well completed in January 2008, initially producing at 1,472 BOPD. In March 2011, during a data acquisition program, 19.5 ft of Electronic Memory Read-out (EMR) gauges, 3,506 ft of slickline and a 2-1/8-in. bottom sub from a wire cutter were left in the hole. To prevent these "fish" moving to the surface, a 3.65-in. permanent packer with a perforated sub (ID 2.6 in.) was set in the hole, which led to a steep production decline. In February 2012, the well started to flow intermittently and a gas lift valve change out (GLVCO) was planned immediately to improve the production. However, of the five sidepocket mandrels (SPM) previously installed, only SPM #1 and #2 were accessible because of the tubing packer installed at 2,750 ftMD. The team decided to execute a GLVCO on mandrel #2 at 2,730 ftMD, where the deviation reached 63°, which prevented a gravity-dependent slickline GLVCO operation from reaching depth. Furthermore, the hydrostatic pressure of the 9.4-ppg packer fluid in the annulus created a casing pressure 700 psi higher than pressure inside the tubing. A conventional slickline GLVCO would not be able to handle the U-tube effect on the dummy valve removal operation. There was a risk that the dummy valve and kick-over tool (KOT) would be violently forced up-hole inside the tubing and tangle with the slickline. To overcome these issues, an electric-line-based GLVCO was needed. The assembly consisted of an e- line tractor to convey the KOT to the desired depth and a hydraulic stroking tool to provide additional force for gas lift valve (GLV) removal or installation. The well Stroker tool was equipped with an anchor to hold the KOT steady in position during the dummy valve retrieval and GLV installation. This paper describes the planning process and successful GLVCO execution based on an electro-mechanical and a hydraulic tool operation.