Abstract: Systems and methods include a computer-implemented method for generating and modeling oil viscosity profiles. An Equation-of-State (EOS) and a field pressure-volumetemperature (PVT) model are generated by reconciling historical well data received for multiple wells in a field of interest. Oil properties trends for checking logical tendencies for in-situ oil composition for local data and at initial conditions are generated using the EOS and the field PVT model, calibrated using measured lab-available oil density, and used to generate an in-situ oil composition for local data and conditions. An oil viscosity profile, generated in the field PVT model based on the oil properties trends, is calibrated and modeled in a two-dimensional PVT model using lab oil viscosity. The two-dimensional PVT model is tested using static and dynamic simulation models in terms of the EOS, compositions, composition gradient, and oil properties, including viscosity.

Abstract: The systems and method described in this specification relate to a method for determining a residual oil saturation of a reservoir. The method includes obtaining a plurality of rock samples from the reservoir; determining a permeability of each of the rock samples; measuring a fluid viscosity of oil in the reservoir; estimating a location-specific permeability of the reservoir across the reservoir based on the permeability of each of the rock samples; determining a location-specific displacing velocity of the reservoir based on a function of the location-specific permeability and the fluid viscosity of the oil; determining the residual oil saturation of the reservoir based on the location-specific displacing velocity using Franklin's equation; and predicting a recovery of the oil from the reservoir using the residual oil saturation in a computational model of the reservoir.

Abstract: Disclosed are methods, systems, and computer-readable medium to perform operations including generating a material balance plot for a plurality of wells in a gas reservoir. The material balance plot includes, for each of the plurality of wells, respective static pressure/compressibility factor (P/Z) values plotted against cumulative production in the gas reservoir. The operations further include calculating, for each of the plurality of wells, a respective slope of the respective P/Z values plotted against cumulative production. Also, the operations include grouping, based on the respective slopes and locations of the plurality of wells, each well into a respective cluster. Additionally, the operations include designating each respective cluster as a separate compartment in the gas reservoir.