The effect of wellbore circulation on building an LCM bridge at the fracture aperture

The results showed when stirring the sample, a higher fluid loss was required before the sample sealed and the maximum sealing pressure (Pmax) was lower than sealing pressures reported from conventional tests. Different LCM recipes required a different minimum flow rate for a seal to initiate at the Scirc. Increasing the flow rate improved the sealing effectiveness ratios of all LCM recipes. At high flow rates some recipes gave very similar Pmax as conventional tests while others lost more than 35% of their strength. At a given flow rate with larger opening size slot, the effect of Scirc was amplified as higher fluid loss was required to initiate a seal and a lower sealing effectiveness ratio was recorded. The most significant new finding is that LCM with lower specific gravity was less prone to the Scirc making them better preventive approach candidates.