Patent ID: 8825408
Filing Date: 2014-09-02
Classification: E21B

Abstract:
1. A method of characterizing a fluid in a reservoir using asphaltene content to determine whether the fluid has an equilibrium distribution as a function of depth within the reservoir, the method comprising: (a) using a tool to acquire tool data for a plurality of fluid samples within the reservoir, wherein each fluid sample is at a different depth in the reservoir; (b) determining formation properties for each fluid sample to obtain formation property data; (c) determining fluid properties for each fluid sample to obtain fluid property data; and (d) in a computer processor, using a mathematical model based on gravity and solvency power to determine a predicted asphaltene content as a function of depth in the reservoir, wherein the mathematical model uses at least one of the tool data, the formation property data, the fluid property data, or known fluid reservoir data to determine the predicted asphaltene content; (e) comparing at least one measured asphaltene content at a depth in the reservoir with the predicted asphaltene content from the model at that depth to predict whether the fluid in the reservoir has an equilibrium distribution as a function of depth within the reservoir.