oa Reservoir Quality Assessment of Tight Gas Reservoirs - Links to Producibility

Quantification of porosity types and sizes coupled with in-situ reservoir capillary pressure data allows one to estimate the potential hydrocarbon pore volume in a hydrocarbon transition zone. This data coupled with economic gas rate, production and reservoir quality data (such as sandstone compositional and textural trends on a field or basin scale) can provide a tool to evaluate Conventional vs Tight-Gas zones in a prospect. Conventional gas reservoirs consist predominantly of primary intergranular porosity with large pore-throat sizes and varying amounts of secondary porosity. In contrast, tight-gas reservoirs (i.e. a reservoir which requires artificial stimulation to produce at economic rates) consist predominantly of secondary porosity with pore-throat sizes well below 1 micron in diameter.