An interpretation of data after performing Step-rate-test in multi-layered, unconsolidated and weakly consolidated reservoirs

Abstract

The prerequisite for this study is the difficulty in interpreting data after stimulation of the bottomhole formation zone has been carried out. The objectives of this work are the applicability and interpretation of Step-rate-test (SRT) data to evaluate suitable injection regimes in multilayered, unconsolidated and weakly consolidated reservoirs and the demonstration of the correlation between injection rate and pressure in a graphical format. We investigated the stability of the reservoir structure to pressure gradients by increasing pressure and injecting fluid through the injection well stock. We concluded that this stability does not improve over time. This means that the practical significance of this method lies in its ability to alter the pressure gradient when injecting fluid to maintain a constant flow rate. The constancy of the pressure gradient has a major impact on the stimulation of the bottomhole formation zone and therefore it can be concluded that the reservoir properties in the bottomhole formation zone are dynamic in nature and can change over time. It should be noted that the study found that a change in pore pressure within the loose rock can also affect the phase (effective) permeability, which in turn can affect the required pressure gradients during injection.