Rigless Well Intervention Deploying Straddle Packer System

Abstract

This paper presents an in-depth analysis of a low-cost solution designed to economically sustain production and avoid high workover expenses. It explores the technical and commercial aspects of straddle packer technology as an alternative to traditional rig-based workovers, which typically require tubing replacement. The discussion also covers the optimum deployment method for this technology and the operational risks involved.

In gas lift wells, a key factor in production optimization is deepening the gas injection point as much as possible to lower bottomhole flowing pressure and enhance drawdown—especially in wells characterized by a high productivity index. One of the most challenging constraints to achieving this is the presence of holes in the tubing string. The straddle packer offers an effective solution, as it seals off tubing holes (regardless of length), thereby allowing gas injection at a deeper point. Success depends heavily on accurate depth correlation and precise setting of the straddle.

This paper introduces a case study involving the deployment of a straddle packer spaced with a 25 ft spacer to cover a 10 ft long crack in N-80 tubing. Three deployment methods were evaluated: slickline, electric line, and digital slickline. While slickline offered the advantage of mechanical jarring, it lacked correlation tools (GR or CCL). Electric line provided precise depth correlation but couldn't ensure proper straddle setting. The optimal solution was digital slickline, which combined built-in CCL for accurate depth correlation with jarring capability. This method was successfully used to restore a long-term shut-in well, resulting in a production gain of 600 BOPD and recovery of over 0.5 MMSTB of reserves. The well was the only sink point in the reservoir compartment.

The operation proved to be an excellent alternative to costly rig-based workovers—particularly offshore, where mobilization costs are high. Additionally, it presented significantly less risk to the pay zone (no kill fluid invasion or iron rust contamination) and reduced operational complexity.