Challenging Fishing Operation to Retrieve 1.68-In Wireline Tool in 6-In Horizontal Open Hole: Case Study from the UAE

Abstract

Abstract In the United Arab Emirates, an operation to retrieve a production logging tool that was lost-in-hole (LIH) yielded numerous insights for future operations. The fishing operation presented several challenges. First, the outside diameter (OD) 1 11/16-in. bottomhole assembly (BHA) was inside an internal diameter (ID) 6-in. open hole. The minimum completion ID was 2.635 in. The operation involved over 3,000 ft of horizontal open hole section in which the last 600 ft were facing upward. Use of the Coiled Tubing (CT) logging equipped with a casing collar locator (CCL) played a crucial role in identifying the precise depth in the horizontal section of the production logging tool, CCL data combined with the caliper readings from a previous run helped to design the fishing BHA for retrieving the LIH tool. The designed BHA was equipped with a cutlip bell guide and an orienting tool with the aim to facilitate the latching. These datasets and challenges were considered by the intervention team in setting the most appropriate fishing strategy. The LIH toolstring retrieval involved six runs. Initially, a conventional fishing BHA was used, but it encountered tagging issues at the gas lift mandrel (GLM). To overcome this, two straight bars were added to the fishing BHA increasing its length and avoid tagging at the GLM. During the second run, surface weight readings indicated that the LIH toolstring was being pushed along the open hole. In the third run, a similar BHA was used while pumping friction reducers. There was no evidence of the fish as the CT reached the end of the well. In the subsequent run, a lead-impression block (LIB) was deployed to detect the top of the fish. However, the LIB came without any visible marks. In the fifth run, the CT reel was replaced with an electric-cable-equipped pipe. The objective was to detect the fish in the open hole using the CCL sensor. Once the tool was identified, the engineering team modeled the fish using caliper readings and deviation survey data, enabling the proper design of the fishing BHA. The BHA was equipped with a cutlip bell guide and an orienting tool, which facilitated the latching and subsequent recovery of the tool in the following run. With the insights gained from this operation, future operations in similar scenarios can benefit from the use of fiber optic-equipped CT. The proper interpretation of fish positioning, aided by caliper and CCL data, will allow for improved decision making in selecting the appropriate fishing tools and techniques. This, in turn, can lead to more successful and efficient retrievals of lost tools, minimizing downtime and potential operational disruptions.