| This research investigates the sealing integrity of various lost circulation material (LCM) in conjunction with barite and silica fumed nanoparticles (NPs). Experimental testing in a water based mud (WBM) at different concentrations of LCM and NP's, as well as at various fracture disc sizes, enabled the analysis of sealing pressure and sealing integrity. This methodology was determined from previous literature results for LCM, as well as NP performance, in wellbore strengthening and reducing fluid loss.;A fabricated version of the "Modified Plugging Particle Apparatus" was used to conduct testing. The apparatus tested various LCM mixtures at both constant rate and constant pressure in order to determine a sealing pressure, as well as the integrity of the seal. The sealing pressure was determined by a calculated differential pressure to be seen while drilling ahead after experiencing a loss zone during drilling operations. On the other hand, the sealing integrity is how well this seal holds while drilling ahead which was analyzed through a transient pressure region after sealing was established. Three different LCM types, two concentrations and three disc sizes were used in the base test matrix. Following base case testing, NPs were used to study the effect of an increase in sealing integrity on the seal. The NPs were chosen based on low pressure fluid loss results that analyzed the effect that chemically and mechanically generated NPs had on reducing the fluid filtrate in a WBM. All experiments were conducted in a mass balance environment with consistent rheology and testing procedures.;Results showed that the apparatus can successfully analyze different LCM mixtures on a fundamental level without the influence of other effects. LCM mixtures have shown to produce higher sealing pressures in the current apparatus than what has been previously reported in the literature. Furthermore, the NPs have shown potential to strengthen the seal as the fracture realizes increasing pressure, depending on the LCM type and NP type. This research further investigates the sealing capabilities of various LCM in conjunction with NPs and introduces a new methodology of understanding the quality of these seals. |
