Underground gas storage design and management requires specific technical expertise, especially to maximize performance and ensure long-term efficiency. Our engineers and geoscientists have been closely involved in numerous UGS projects, particularly in Italy whose working gas capacity, at some 16 billion cubic meters (565 Bcf), is the second largest in Europe and is set to increase. Most importantly, enhancements have been implemented in the reliability of static, dynamic and geomechanical models of the reservoirs and in upgrading tools for the optimization of field management whether this is well count, type and location or storage strategy including delta-pressuring.

All available data is gathered, reviewed and quality checked. If data is available on paper only, including maps and logs, it is digitized and made available in an electronic format prior to organizing it into a database.

A reservoir dynamic model, based on the geological model, is built and calibrated against the historical data collected during the primary production phase.

An advantage of working with depleted reservoirs is the potential availability of existing 3D models.

The dynamic model is then used to predict the actual storage performance (working gas and well deliverability) in time and to potentially optimize the storage strategy.

A geomechanical model is then set up to address rock integrity and deformation issues.

KAPPA offer a wide experience on integrated modeling of reservoirs of various geological and dynamic complexity.

Injection and withdrawal cycles are simulated to estimate working gas, injection rates and deliverability curves given the well and surface facilities constraints.

The conversion of a depleted field or aquifer into an underground gas storage requires the setting of a suitable monitoring system to evaluate the evolution in time of the field performance. KAPPA specialize in dynamic data analysis, including data management from PDG’s, pressure transient analysis and history matching to monitor UGS reservoirs. Furthermore, UGS monitoring should address all the safety issues related to gas leakage and/loss and stress-strain behavior induced by repeated pressure cycles.