Excessive water production shortens the life of producing wells and severely limits their economic viability. Inflow control devices (ICDs) are used to halt water output and compensate for permeability variation by shutting off the sleeve where water production increases. Traditional ICDs need activation and intervention for the water shut-off, which leads to non-productive time, increased cost, and reduced revenue. Intervention-less passive technology addresses this imbalance issue by designing an ICD that highly reduces water breakthrough into the wellbore in virtually any porous media.
The intelligent well completion technology presented in this paper focuses on a modified ICD with no movable parts for water management. The ICD annulus is packed with a porous Polytetrafluoroetheylene (PTFE) sleeve that exhibits water-sensitive control functions. The porous PTFE sleeve causes a differential pressure for water and oil through the modified ICD. Differential pressure occurs because hydrophobic material and brine form droplets due to their higher surface tension, whereas oil flows in a more streamline manner. This situation leads to choking of the pore throat and higher pressure in the flow loop for higher brine cut. Flow testing through porous a PTFE sleeve shows about 200 % increase in differential pressures for 70% brine cuts compared to 0% water cut, which means it can restrict flow when the brine cut increases. The porous PTFE material has high thermal and chemical stability and can tolerate salinities as high as 246,000 ppm for long periods of time. Tests have confirmed the efficacy of the tool remains unchanged, even after flowing brine and diesel through the material for more than 400 hours. Prototype testing indicates that the modified ICD significantly improves recovery performance. This innovative tool will be field tested shortly.
This modified inflow control device offers a novel intervention-less, reversible subsurface water management technology by reducing production from zones with high water cuts.