Electric line deployed well intervention technologies are continuing to grow in use and relevance, this is due to the value provided by a highly efficient and effective means of intervention. It is light on equipment, personnel and logistics, is controlled and precise in its in-well execution, and is less obtrusive to the wellbore, the reservoir and the environment. These valuable characteristics are making electric line deployed solutions the preferred choice of customers for many interventions, whether that be for addressing new well completion, old well rejuvenation or repair, or eventual plug and abandon (P&A) operational scope. Preference is also increasing with those customers who are keen to push the boundaries of these technologies to leverage their beneficial impact across a broader range of intervention operations.
Often, the tasks or workscope assigned to electric line deployed intervention technologies are reserved for what would be considered the lighter end of the spectrum, for example, low volume debris cleanout, small component milling and low force tool manipulation. However, as full system-based intervention technology platforms are developed, incorporating advanced interconnected technology components, the magnitude of what can be achieved has expanded electric line intervention solutions into the realms of work scope previously reserved for heavier methods, like coiled tubing or drill pipe based. That, coupled with the efficient and precise execution and inherently light footprint that electric line deployed intervention brings, is adding to the increased interest in expanding its use.
Two recent electric line deployed wellbore cleanout operations carried out on the Norwegian Continental Shelf involving high volumes of debris demonstrate the advantages this advanced intervention technology platform has enabled, the scalability of its performance, and why it is challenging the traditional thinking and perception of what is possible on electric line.
In the case operation 1, extensive volumes of produced sand had accumulated in a large mono-bore completion preventing the execution of a required P&A operation. In case operation 2, the well had significant Barium Sulphate (BaSO4) scale deposits over much of its length, which prevented well access for a required gas lift valve (GLV) change out. In both these cases, efficient and effective electric line deployed remediation was possible due to the increased performance, in-well task visibility and real-time task control provided by the advanced electric line intervention technology platform that was utilised. Attempting both these cases was strongly encouraged by the customer, leading a one team approach.
For case operation 1, high speed tractor conveyance speeds of over 26 meters/minute were achieved on this multi-run operation. Instrumentation provided real-time indication of collection chambers being full, ensuring minimal time on depth during collection. Consistent high volume recovery rates of 100% were achieved on all but one of the collection runs, with a total of 1400 liters of sand debris being collected, clearing 280 meters of wellbore, at an average of 140 liters per 24 hours. For case operation 2, over 2000 meters of hard scale was milled, at a rate of penetration (ROP) of 44 meters/hour, on average, re-establishing access for required electric line intervention runs and the subsequent change out of the leaking GLV to restore the integrity of the well, enabling it to be put back on line and resume production. Record breaking achievements regarding the volume of debris removed and depth intervals cleaned via the intervention technology platform were made in both cases.
