Fluid Characterization Method for Hydrocarbon Cuts
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Solution Overview
Problem
Current methods for determining fluid characteristics in wells, such as mud gas measurements and Downhole Fluid Analysis, are limited in providing individual information on hydrocarbon cuts beyond C6, leading to incomplete understanding of fluid nature and properties.
Innovation Solution
A method involving the reception of mass ratios and molecular ratios associated with hydrocarbon cuts, conversion and normalization of these ratios, and iterative computation of molecular weight parameters to estimate molecular weights for hydrocarbon cuts, enabling the determination of individual cuts up to C30 in a thermodynamically consistent and vertically continuous manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mud gas measurements (GWD) are used to determine fluid composition, then light end cuts (C1-C5) can be determined with sufficient reliability, but individual information on heavier cuts (C6+) cannot be obtained
Solution Approach 1:
The patent combines data from multiple measurement techniques (GWD for light ends and DFA for heavy ends) into a unified analysis framework. By merging these complementary datasets and applying iterative computational methods, the system achieves complete characterization of all hydrocarbon cuts from C1 through C30+, resolving the information gap for heavier cuts while preserving accuracy for lighter cuts.
2Productivity
If Downhole Fluid_analysis (DFA) is used to provide real-time fluid properties, then grouped composition information (C1, C2-C5, C6+) can be obtained, but individual information on cuts above C6 cannot be drawn
Solution Approach 1:
The patent segments the C6+ grouped data into individual cut components (C6, C7, C8, ..., C30+) through iterative computational analysis. By dividing the lumped C6+ information into discrete molecular weight increments and applying mass balance constraints, the system recovers individual cut compositions while maintaining real-time measurement capability.
Solution Approach 2:
The patent transitions from one-dimensional grouped composition data (C6+ as a single value) to multi-dimensional individual cut information by introducing molecular weight as an additional dimension. This allows the system to distribute the lumped C6+ mass across multiple discrete cuts based on thermodynamic equilibrium relationships and measured constraints.
3Loss of information
If iterative computation with multiple parameters is performed to determine individual cuts C1-C30, then complete fluid characterization is achieved, but computational complexity increases
Solution Approach 1:
The patent performs preliminary data processing and constraint establishment before the main iterative computation. By pre-calculating molecular weights for each cut, establishing mass balance relationships, and preparing initial estimates for the iterative algorithm, the system reduces the computational burden during the actual determination process while maintaining complete fluid characterization.
Data Source
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AI summary
The present invention relates to a method of determination of fluid characteristics in a well, wherein said method comprises: /a/ receiving mass ratios (102) and a molecular ratio (101); /b/converting received mass ratios (104) into molecular ratios based on predetermined molecular weights; /c/ normalizing (105) converted molecular ratios with the received molecular ratio; /d/ determining (108) parameters (α,β) of a sequence defined by (Formula I) so that, at least, a difference between said normalized molecular ratio and an associated member or an associated sum of members being minimized; /e/ computing (110) an estimated molecular weight (Mw6+) function of (Formula II); /f/ if a stabilization criteria is met (111), the steps /b/to /f/ are iterated with the estimated molecular weight as one of the predetermined molecular weights in step /f/.