PROSPECTS FOR CO2 STORAGE IN THE SUBSURFACE OF THE BEEKMANTOWN GROUP (CAMBRIAN– ORDOVICIAN), WESTERN NEW YORK

Injection of CO₂ into deep-subsurface, porous, and permeable formations may be the most environmentally acceptable method of gas storage. Thus, careful investigation of possible storage sites in deep geologic formations is required. This research provides information about the petrophysical characteristics of selected deep wells in the Beekmantown Group (Cambrian– Ordovician) of western New York. Stratigraphically, the Beekmantown Group mainly consists of a basal sandstone unit (Potsdam Formation) that grades up to a carbonate unit (Theresa Formation).

Micoscopic obsevation of the pore system revealed different types of porosity including interparticle, interacrystal, moldic, micro-channel, and vugs. The Scanning Electron Microscope (SEM) is used to study the micro-pore structure and their related geometric patterns.

The capillary-pressure test using the Mercury injection technique is used to evaluate the petrophysical parameters of 48 core plugs. Mercury was injected and pressurized incrementally to a maximum of 25,000 psi. 30 measurements were taken for each sample at the particular incremental values. Petrophysical parameters including porosity, permeability, recovery efficiency, and fluid saturations were calculated. Subsequently, the Beekmantown strata is classified into different petrofacies. These petrofacies are as follows: 1. Low porosity and high recovery efficiency; 2. High porosity and low recovery efficiency; 3. Intermediate porosity and intermediate recovery efficiency; 4. Low porosity and low recovery efficiency.

Microscopic and petrophysical analyses support that the Potsdam Sandstone and some intervals within the Theresa Formation have the reservoir quality and the acceptable thickness that make them suitable sites for CO₂ storage.