Pressure Pulse Testing Method for Caprock Characterization

Abstract

Pressure transient testing is a method to obtain information on reservoir characteristics. Thin shale layers isolating productive intervals in a reservoir have important implications for reservoir development and EOR strategies. In addition, weaknesses in caprocks overlying injection intervals may adversely affect the safety of fluid injection approaches including gas storage, waste water disposal, and CO2 geological storage. Even low permeability of a caprock overlying the injection zone can be very important by allowing for pressure dissipation out of the reservoir. In this work, we apply harmonic pressure testing method to characterize a caprock overlying a given injection zone. The diffusivity equations are written and solved in frequency domain for system of injection layer and above zone with the low permeability caprock in between. A vertical well is perforated in the middle of the injection layer. A periodic flow rate pulse is disseminated from the injection well. The pressure pulses traveled through the caprock are observed in the above zone. The hydraulic characteristics of the low permeability caprock are estimated applying the analytical solution based on the above zone pressure amplitude. The caprock diffusivity is found to be in acceptable agreement with the true value. It is shown that the harmonic pulse testing is useful to characterize the intra/inter reservoir low permeability layers (caprocks).

Computer simulation of strength testing of an object based on signal shaped resources

“…These include testing, an expensive and time-consuming stage in the development of software systems [2], spectral analysis of diagnostic signals [3], ultrasonic sensing [4], pulse testing [5], integration of advanced CAE tools and test environments [6], modelbased testing [7], micro-level computer processing [8], patterns for natural language translation in SQL queries [9]. Especially it should be noted the most common method of shock testing in all its diversity [10]. In the question of model-based testing, it should be noted that testing is an approach in which tests are built manually, in an automated way, or generated completely automatically based on a model of the behaviour of the system under test and a model of situations associated with its operation [11].…”