An international oil & gas company operating in Malaysia needed to perform acid stimulation in order to enhance gas production from an otherwise declining asset.

To achieve the most efficient operation possible, which involved negotiating challenging deviations of 86° to reach the target zone in the horizontal section, the client opted for a third-party acid stimulation solution from StimStixx Technologies, and conveyance via Well Tractor®.

This combination provided a more efficient and cost-effective intervention in comparison to a coiled tubing (CT) alternative, with a rapid setup capability, and fast delivery of the acid solution to specific spots in the target interval.

A full System Integration Test (SIT) was conducted prior to mobilization in order to develop an operation program combining a Well Tractor and StimStixx for the first time. The simple logistics of mobilizing lightweight equipment produced a minimal footprint, and an effective rig-up time of less than 24 hours.

During the operation, the average tractor activation was 2,100 ft/run, with a total of 11 runs, including six logging runs and five acid stimulation runs.

Acid was successfully delivered to the chosen areas within the target interval, with no corrosion observed on the tools or the cable, indicating correct dispersal had taken place.

The total distance tractored during the entire operation was 19,614 ft.

This successful operation marked the first-ever combined run of a Well Tractor and StimStixx acid solution, providing the client with a fully optimized operation in terms of timeframe, and the volume of chemical required.

By running the operation on e-line, the amount of acid required per run was minimized in comparison to an alternative CT acidizing or pumping unit operation. The precise spotting of the acid solution was carried out across the target zone in the horizontal section. Furthermore, by eliminating the need for fluid injection inside the well, long-term reservoir performance was safeguarded.

The utilization of e-line intervention delivered an incredibly cost-efficient operation, also enhancing safety due to there being no requirement to manage live acids at the well site.

Preliminary data gathered following the operation indicated a positive impact on the production of the well. This technology combination is a cost-effective game-changer for light acidizing in highly deviated wells.