Patent ID: 8666667

Claim:
An allocation method for allocating production among a plurality of reservoir compartments in a subterranean formation, the allocation method comprising the steps of: (a) obtaining a compartment sample from each of the reservoir compartments, each reservoir compartment having a reservoir fluid, wherein each reservoir fluid is characterized by a plurality of components, wherein the plurality of components comprises a plurality of carbon-based components, wherein each carbon-based component of each reservoir compartment comprises a plurality of stable carbon isotopes; (b) analyzing each of the compartment samples to determine a composition fraction of one or more of the carbon-based components of each reservoir compartment; (c) analyzing each of the compartment samples to determine a stable carbon isotope value of the one or more of the carbon-based components of each reservoir compartment; (d) allowing a fluid to flow from each reservoir compartment and commingle to produce a commingled output production stream, the commingled production stream comprised of a relative contribution from each reservoir compartment; (e) analyzing the commingled production stream to determine an output composition of each of the one or more carbon-based components of the commingled output production stream; (f) analyzing the commingled production stream to determine an output stable carbon isotope value of each of the one or more carbon-based components of the commingled output production stream; (g) determining a composition-based relative contribution of fluid from each reservoir compartment by solving a first mass balance system of equations for each of the one or more carbon-based components, wherein the first mass balance system of equations is characterized by a first mass balance of each of the one or more carbon-based components from each reservoir compartment mixing to produce the commingled output production stream; and (h) determining an isotope-based relative contribution of fluid from each reservoir compartment by solving a second mass balance system of equations for each of the one or more stable carbon isotopes, wherein the second mass balance system of equations is characterized by a second mass balance of each of the one or more stable carbon isotopes from each reservoir compartment mixing to produce the commingled output production stream.