Simulation of ASR using Petrel
Click here to enlarge imageThe arid climate of the United Arab Emirates (UAE) presents several challenges for maintaining sustainable water supplies for domestic, industrial, and agricultural uses. The UAE has one of the lowest global renewable water resource capacities due to low rainfall rates, high evaporation, no reliable surface water resources, along with a high per capita water consumption rate. This combination of factors created an imbalance between water supply and demand, and increased the region’s reliance on new water resources including desalination, groundwater recharge initiatives, water reuse, and strict water conservation programs.
Aquifer storage and recovery provides:- Substantial underground water storage with high recovery rates
- Significant cost savings when compare to surface water storage
- Reduced reliance on vulnerable, costly, surface water reservoirs
The rapid economic expansion, coupled with sharp population growth of the Emirate of Abu Dhabi has created an immediate need for water reserves, not only to meet the increasing population demands, but also to secure a contingency plan. Use of surface water storage tanks was initially considered for the region; however, it was concluded that this method wasn’t a viable alternative for Abu Dhabi due to the high cost and risks to the environment that it posed. ASR provides a means of supplementing water supplies in arid climates, and is a cost-effective option when compared to conventional surface storage, as surface land requirements for ASR are minimal.
SWS recommended the adoption of an ASR site to the Mubadala Development Company (MDC). The project was designed to provide a secure method for strategic subsurface water storage with minor surface installations. MDC focuses on the generation of sustainable economic benefits for Abu Dhabi through a careful selection of business ventures, in partnership with local, regional, and international investors. MDC invested in this project to diversify and support further development of a rapidly growing economy.
SWS worked in conjunction with the Environmental Agency of Abu Dhabi (a governmental agency responsible for the protection and conservation of the environment) to identify and test a potential site for the ASR project by defining the storage zone, aquifer thickness, related hydraulic parameters, and subsequent testing of the identified aquifer’s potential for ASR through pilot testing.
The initial phase of the project was to locate a potential ASR site. This was achieved through compilation of geological and hydrological information such as lithology, geophysical logs, water levels, water quality data, seismic data and base maps. Data was initially compiled in both GIS and HydroManager databases, then three dimensional hydrogeological models were developed using Petrel and ECLIPSE, advanced groundwater modeling and simulation software developed by SWS.
Each proposed ASR location was ranked to determine an optimal location and to develop an exploratory drilling strategy. Wells were drilled on the sites that received the highest rankings, and data was collected using the latest geophysical logging technologies developed by Schlumberger, including PlatForm Express (PEX), Combinable Nuclear Magnetic Resonance (CMR), Elemental Capture Spectroscopy Sonde (ECS) and Fullbore Formation MicroImager (FMI) tools.
Each of the wells in the project area were also equipped with Diver™ dataloggers to continuously monitor water levels, providing a reliable log of changes in response to hydraulic pumping tests or source water injection. The data collected was then analyzed using AquiferTest Pro to determine the hydraulic properties of the aquifer. The results confirmed that the aquifer of the selected site exhibited the desired storage characteristics.
The pilot test phase of the project was conducted to confirm the feasibility of implementing a large-scale ASR project in the area. In this phase, an ASR well was drilled in addition to a number of monitoring wells within the project boundaries. The test included cycles of injection-storage-recovery, a thirty day storage period to assess potential hydrochemical interactions, advanced water chemistry analysis, and the collection of monitoring data from the surrounding wells during the cycles. Petrel Simulation of ASR using PetrelECLIPSE-H2O for dynamic groundwater simulations, AquaChem and PHREEQC for water compatibility predictions, in addition to HydroGeo Analyst for complete groundwater and borehole data management, analysis, and visualization.
The test phase proved ASR to be a cost efficient, secure solution for strategic and seasonal storage of water and the system was adopted by the government of Abu-Dhabi.
Schlumberger Water Services is based in Waterloo, Ontario, Canada. Contact: www.water.slb.com
