The goal is to develop alternatives for natural gas storage in market areas where conventional storage options may be technically unfeasible.
New York State Museum – Project management and all research products
Sandia National Laboratory (SNL) – Modeling and rock mechanics testing
The objective is to identify potential northern Appalachian Basin rock formations available to industry for disposal of brines generated during the development of gas storage caverns in subsurface salt deposits, and develop a model for safe and economic disposal of these brines.
The northeastern states have had a growing demand for gas during the winter heating months and electric power generating companies have also been increasing their demand for gas. Shortages are possible if sufficient natural gas storage capacity is not available. Caverns created in subsurface salt formations can be very efficient “containers” for storing natural gas, especially for meeting peak demands on a daily basis. To develop caverns, an economic and environmentally safe means must be found to dispose of the brine created during solution mining of a salt deposit.
This project addresses the problems and possible methods related to the handling of these liquids. Potential injection formations and salt bodies with the potential for cavern development have been identified. A working system model will be developed for the deep well injection of brine that can serve as a blueprint for feasibility studies of brine injection for other regions of the United States.
Phase I of this two-phased project focused on defining areas where developing a cavern is a possibility in the most basic sense. Knowledge of where in central New York the Silurian salt deposits can be found is crucial to the successful completion of any cavern development attempts. Salt intervals of interest must be at least 100 feet thick and at depths of between 2000 and 6000 feet. Phase II of the project defined formations with potential as brine disposal reservoirs, within the area defined in Phase I.
Phase I primarily served to bring existing data from previous studies of the Silurian section in New York State together with data from new wells drilled since the completion of those studies. A complete well data set for the Silurian section along with detailed cross sections and maps with a focus on areas with usable salt were the products of this phase.
The focus of Phase I efforts has been the Syracuse F unit because it offers the best potential for salt of the appropriate thickness for cavern development. In south central New York the F unit is greater than 100 feet thick in Stueben, Schuyler, Chemung, Tompkins, Tioga and a small portion of the surrounding counties. Within this area there are several smaller isolated areas of very thick salt (sometimes reaching thicknesses greater than 400 feet) in the vicinity of Bath, Baldwin, Tyrone and Catherine townships. Over-thickening of the salt in these areas has been linked by many authors to horizontal movement of a large segmented thrust sheet over a decollement within the Silurian section itself.
Phase II focused on defining what would make individual sites suited for this type of storage, outlining criteria that can help an operator through this process in the future. Criteria for Phase II related to locating formations with the potential to act as brine disposal reservoirs, disposal being currently the most significant obstacle to salt cavern development in the northeast. These formations must have the appropriate lithology, (either sandstones or carbonates), evidence of good porosity and permeability, and a history of production in the area. Also, the best candidates would be those not currently being used (or considered) for conventional depleted reservoir gas storage.
These criteria allowed the researchers to high-grade potential disposal reservoirs from the units available in central New York. The first cut resulted in three potential brine disposal formations: the Upper Ordovician Queenston formation, the Middle Ordovician Trenton-Black River groups and the Cambro-Ordovician Beekmantown groups.
The Queenston Formation is considered to be shale in much of western New York, but in Central New York it becomes a much coarser sandy shale or, moving into the southern portion of the state, a sandstone. The Queenston has potential based on its lithology in the area of usable salt and because of its long history of production in the Auburn area. The formation is thought to be saturated with water in the area where the salt is thick enough to make storage caverns.
The Trenton-Black River section is currently the most prolific play in New York State and many of the fields are located within the region of usable salt. One of the most attractive points about this interval is that operators believe the fields may prove to be unattractive for conventional depleted reservoir type gas storage due to their heterogeneity and unknown lateral extent.
The Beekmantown Group offers potential for brine disposal reservoirs in its porous dolomite and hydrothermal breccias and also possibly in sandstone intervals. A Beekmantown Study in Ohio showed widespread porosity in the “B” unit and a study in the Mohawk Valley region of New York has also shown evidence of laterally-extensive porosity. The Beekmantown is thought to be water-saturated in the area of usable salt.
Each of these formations was modeled using a program created for this project by Sandia National Labs. The model revealed that because the Queenston and Beekmantown are saturated with water and have relatively low permeabilities, they cannot accept the large quantities of brine required during salt cavern construction.
The Trenton Black River, however, is a viable option because the formations contain significant residual gas saturations and wells already drilled into the formation can serve as disposal wells. Many of these are horizontal wells, which will further help to disposal of brine at an economic rate. These reservoirs are very heterogeneous, making them poor gas storage reservoirs and potentially good brine disposal reservoirs.
This project has been completed. The final report is available below under "Additional Information".
$324,932 (FEW02-011307; $162,000)
Final Report [PDF-20.97MB]