Analysis of Nonisothermal Injection and Falloff Tests in Layered Reservoirs

Abstract

The effects of reservoir layering and gravity segregation on nonisothermal injection and falloff tests are investigated. Results show that layering does not affect injection or falloff data if all the layers are permeable and accept fluids from the wellbore. In such cases, the average permeability, skin factor, and distance to the thermal front can be calculated using the technique developed for homogeneous reservoirs. Special considerations have to be taken for cases where several layers are impermeable or are permeable but do not accept fluids of the well face. In the first case (impermeable layers), knowledge of the total thickness of the permeable layers is required for the exiting techniques to be applied successfully. In the second case, the existing technique cannot be applied, but characteristics responses from injection and falloff test are seen; therefore, this case can be identified easily.