Unblocking Flow Assurance and Transport Uncertainties in Oil Wells with High Sand Production with Dynamic Simulation

Abstract In the Colombian Llanos basin, there are many prospective unconsolidated sands with a very high oil potential, that at the same time can be considered as a nightmare for oil production, since the sand transport is a common factor that must be analyzed and handled. That is the case of the F-01 well, where several flow assurance issues related with sand production were occurring such us pump damage, tubing erosion, sand control equipment rupture in others which were causing so much deferred production and well intervention events negatively impacting the field production and by that opening a gap in the targets ambition. Determine the sand behavior in the production system was crucial to find the best operating conditions of the well, understanding sand concentration points, critical particle velocities, the amount of sand that must be carried out with the production and its effect in all of the wellbore equipment components. First of all, a data analysis was performed, the production history data was reviewed along with the well events, interventions, operating conditions and the accumulated sand production as an input, due to the intermittency of the well, a stable period was selected to reduce possible noise in the variables followed up by the well modelling phase, using a dynamic simulator representing the current well conditions, production and particle behavior. Several scenarios were executed varying the principal system elements that could generate changes in the fluid and particle velocities, and by that it was possible to find that in this case, the wellbore was highly affected by the diameter change of the downhole components as well as that the accumulation points were not the ones suspected by the analysts but others that the operation were not able to explain so far. Also, the critical particle velocity for a stable operation was determined as 0.71 ft/s or above having a sand production of 45 to 600 PTB, and a critical flowrate of 1800 bls/d to avoid accumulation. This study has served as reference for the neighbor, and new wells drilled in the field, and its results has been used as a new insight for the field operation constraints and can be used as a reference in wells with sand transport issues.