An Empirical Correlation for Estimation of Transition Time Bbtween Deep Bed Filtration of Particles and External Filter

Nowadays, waterflooding is the most commonly used recovery method for oil reservoirs. Numerous fields suffer from sever formation damage during waterflooding and pressure maintenance operations.

The two most responsible mechanisms of formation damage are solid particles filtration of the injection fluid into the reservoir rock (deep bed filtration) and subsequently deposition of the particles on the injection face which leads to formation of the external filter cake. Transition time is defined as the time when deep filtration of particles stops and cake starts to build up. Determination of transition time could decrease the unexpected problems caused in the injectivity impairment and experimental design for waterflooding and disposal operations. Damage will reduce the formation permeability and decline the injection rate or increase injection pressure. Recognizing the severity of the damage and the time of its formation can lead us to a proper design for injection planning. Numerous researchers have reported deep filtration of particles in the injected water and subsequent formation of external filter cake on the injection face. In this paper, a simple correlation is developed for determination of transition time based on reported data form literature which unlike the previous studies accounts for both pore and particle size.