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Abstract Curing total losses of drilling fluids in fractured formations is one of the most challenging fluid loss scenarios to control. Loss zones are unpredictable due to large vugular zones, extended and connected fracture structures formations. However, based on proper evaluation of the offset wells data, losses events can be anticipated to customize a Lost Circulation Material (LCM) solution. Non-Conventional LCM solutions typically are used to go beyond and be more aggressive, aiming to cure the losses, reduce non-productive time and resume programmed operations. We worked to locally develop an Innovative Non-Conventional LCM solution, which involves pill trains combinations to cure the losses across fractured formations. After successful lab testing verification, those formulations were implemented at the field with satisfactory results. Well A was identified with total losses across fractured formation. Previously lab tested Non-Conventional LCM solution was recommended. At Well A location, the first pill was made with blend of organic polymers with super absorbent materials, specifically designed to impart viscosity and swell as it fills the fractures. producing a viscous slurry designed to flow into downhole loss zones, where it will swell and seal large fractures providing a base for the second pill pumped to rapidly de-water, leaving behind a drillable plug. The second pill pumped consisted on a blend of sealants which form a stable, high solids, high fluid loss LCM slurry. Upon contact with a thief zone, this second pill will rapidly de-water, leaving behind a drillable plug-in fracture, voids and vugular spaces across the loss zone. A soft squeeze was hold for several hours. The resulted plug was easy drilled through without the danger of unintentional sidetracking. As conclusion, we were able to customize an Innovative Non-Conventional LCM solution to regain the circulation on well A, allowing them to continue with the programmed operations and eliminating non-productive time in this well. This paper discusses how this innovative customized Non-Conventional LCM Solution was designed, lab and field tested with successful results curing total losses scenarios across fractured formations, resulting in considerable non-productive time mitigation while drilling across losses zones.
Olivares et al. (Mon,) studied this question.