Injectivity impairment during produced water disposal into low-permeability völkersen aquifer (compressibility and reservoir boundary effects)
Abstract
Compressibility needs to be accounted for when estimating injectivity decline for water disposal in gas reservoirs and in closed aquifers, and for waterflooding of gas-condensate fields. The problem with given wellbore pressure at the injector aims avoiding the reservoir fracturing. An analytical model is developed that provides well injectivity index decline with time. Under this model, the solution of damage-free compressible flow in a closed reservoir is asymptotically matched with the impedance growth formulae for incompressible flow in the well vicinity. For the well regime of a given wellbore pressure, the injection rate decline is described by a nonlinear integro-differential equation that is solved iteratively. The solution under the field conditions investigated shows that well impedance grows faster during deep bed filtration than during external cake formation. This unusual pattern is explained by low permeability of the reservoir. Well impedance is more sensitive to the effect of formation damage than to the compressibility effect of rock and water. Lower formation damage, higher compressibility, or lower injected particle concentration results in larger total injection volume into a closed reservoir.
RAS ID
36510
Document Type
Conference Proceeding
Date of Publication
2016
Funding Information
DEA Deutsche Erdoel AG
School
School of Engineering
Copyright
subscription content
Publisher
Society of Petroleum Engineers
Comments
You, Z., Kalantariasl, A., Schulze, K., Storz, J., Burmester, C., Künckeler, S., & Bedrikovetsky, P. (2016, February). Injectivity impairment during produced water disposal into low-permeability völkersen aquifer (compressibility and reservoir boundary effects) [Paper presentation]. SPE International Conference and Exhibition on Formation Damage Control, Lafayette, Louisiana, USA. https://doi.org/10.2118/179026-ms