Abstract This study addresses lost circulation of drilling fluids as one of the most challenging drilling issues. The study proved the superiority of unique composition of blend of recycled rubber material with organic plugging materials to enhance fluid loss control. The success criteria have been set as the following: (1) Cost efficient compared to available solutions (2) Superior performance to conventional LCMs (3) Supply sustainability and environmental impact. A comparative laboratory assessment is conducted on conventional as wells as the newly developed LCM pills. These pills were evaluated using a 20/40 mesh sand bed at different sand bed compaction levels. The LCM pill is placed on the top of the sand bed and mounted in a modified API test cell that is connected to a nitrogen gas cylinder to apply required pressure on top of the loss control slurry. The applied pressure simulated overbalance pressure during the treatment of a loss zone. Experimental results have shown that conventional LCM pill escaped through the permeable sand bed matrix immediately after the application of 100 psi overbalance pressure. In the developed LCM case, though, there was a slight drop in the slurry level due to an initial slurry invasion into the sand bed matrix, but no further drop has been noticed afterward. Also, conventional LCM pill formed thicker cake compared to the developed pills. This is because thinner cake reduces the likelihood of pipe sticking issues. The visual and digital data obtained clearly have shown excellent sealing and blocking of 2 mm slotted disc at 500 psi overbalance pressure both at room temperature and at 250 F temperature as it quickly created a bridging effect. The chemicals requirements needed are evaluated and compared to conventional LCM pill where supply of the developed LCM pill can be sourced locally with reduced cost. In addition, the recycled rubber contributes to a sustainable circular economy. This study contributed to circular economy by providing enhanced solutions to cure loss circulation. The engineered LCM pill is superior to conventional LCM pills in terms of performance in sealing and blocking along with cost effectiveness in loss circulation zones.
Alturkey et al. (Tue,) studied this question.