Å håndtere store slamtap under boring er en stor utfordring for oljeindustrien. Dagens løsninger er tidkrevende og kostbare. Innovasjonen At-the-Bit Mud Loss Control inkluderer nedihullsteknologier for en kontrollert og umiddelbar håndtering av slike tap. Nøkkelegenskapene til det nye verktøyet involverer nedihulls lagring og utløsning av en svært svellbar granulær polymerblanding som sveller rundt 60 ganger når den utsettes for boreslam. Dagens løsning er skreddersydd for bruk sammen med vannbaserte borevæsker. Utviklingsprosjektet er i fase 4 med brønnpilotering og kvalifisering. Petroleumsindustrien anerkjenner det høye verdipotensialet knyttet til sikker og kostnadseffektiv boring og redusert logistikk.
The At-the-Bit Mud Loss Control technology aims at on-demand and instant downhole solution for treatment of severe and total mud loss. The circulating drilling mud will be converted downhole to a swelling pill by use of a super absorbent polymer. A special designed superabsorbent polymer has been developed for use in water based mud (WBM) together with suitable carrier fluids. The tool prototype consists of several components inserted as a part of the drillstring. From top to bottom, the tool assembly consists of; pressure compensator, flow diverter (ball operated), dual pipe concentric polymer carriers, release sub and ball catcher. The total length of the tool is around 30 m and is located above bottom hole assembly (BHA). The polymer with carrier fluid payload is around 400 litres which will give a downhole pill of around 12 cubic meters when fully swelled.
The prototype has been functionality tested both at the yard and in an experimental well at the EnergyX and Xrig facilities at Ålgård outside Stavanger during a DEMO2000 project (2020-2021).
This new application is a continuation for well piloting in oil wells. A one year program is anticipated with two pilots. This will include onshore wells in USA and the Middle-East.
The R&D challenges include the investigation of the drillability of the innovations with use of concentric dual casing tubulars. Also, finding appropriate well candidates to demonstrate the sealability of lossy formations needs much attention in the well planning phase. The thief zones may include both natural and induced fractures. Karstified carbonate formations may give special challenges with potential high mud losses.