nriperiod

Nriperiod is a diagenetic and low-maturity transformation of organic matter from Type III kerogen into Type IV kerogen in sedimentary basins. It typically occurs at temperatures between 100 and 180 degrees Celsius and under increased pressure conditions. Nriperiod represents a transitional stage between the oil window and the gas window in the evolution of organic matter.

During the nriperiod, the transformation of the organic matter is characterized by the degradation of the more reactive methyl groups to shorter-chain aliphatic compounds, such as methane and dissolved carbon. These compounds are subsequently lost to the aqueous phase or are retained within the kerogen matrix. The residual organic matter is transformed into a more stable, solid state, which retains a variable proportion of the original hydrogen and carbon content.

The properties of the organic matter transformed during the nriperiod are distinct from those generated during higher-temperature diagenetic processes. The resulting organic compounds exhibit lower hydrogen-to-carbon ratios and higher atomic ratios compared to their oil-window counterparts. These differences make it challenging to correctly identify the maturity stage and the degree of thermal stress on the organic matter in sedimentary basins.

Nriperiod knowledge has significant implications for sedimentary basin evaluations, as it regulates the potential to form commercial-level hydrocarbons, predicts CO2 depth potential, affects reservoir characteristics, and informs enhanced oil recovery (EOR) and potential secondary oil recovery (SSOR) possibilities. It also impacts the design and operation of drainage operations and promotes better development and stimulation of productive facilities in adaptations to changes in initiated period-related geological supplies.