In most nonthermal injection processes, fluids are injected at temperatures much lower than reservoir temperatures. Even though injected fluids are heated due to the prevailing geothermal gradient, in most applications, they reach the formation at temperatures far lower than the reservoir temperatures and cool the formation in the vicinity of the wellbore. The temperature lowering could cause solids precipitation particularly for paraffinic crudes and for oils susceptible to asphaltene precipitation. In this paper, the effect of cold-water injection in paraffinic crude reservoirs has been studied.

Temperatures of water reaching the formation were calculated using an analytical wellbore model modified to include realistic wellbore resistances. These temperatures were observed to be below the cloud points of paraffinic crudes. Solid-liquid equilibrium calculations showed that there was a strong possibility of paraffin precipitation under certain injection conditions. The effect of precipitation on oil recovery was analyzed using the method of characteristics approach. The calculations showed the extent of reduction in oil recovery due to paraffin precipitation near the wellbore.

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