neqsim-pseudocomponent-split-characterization

Splits C7+ plus fractions into pseudocomponents using Whitson gamma distributions and split factors.

4|2|Updated May 31, 2026
One-click install
npx skills add https://github.com/equinor/neqsim-community-skills --skill neqsim-pseudocomponent-split-characterization-equinor
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: neqsim-pseudocomponent-split-characterization
Source: https://github.com/equinor/neqsim-community-skills/tree/main/skills/pvt/pseudocomponent-split-characterization
Command: npx skills add https://github.com/equinor/neqsim-community-skills --skill neqsim-pseudocomponent-split-characterization-equinor

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Reservoir fluid characterization often requires dividing a heavy plus fraction (C7+) into pseudocomponents or reconstructing detailed compositions from lumped ones, which is tedious to implement correctly. This Skill provides dependency-free Python helpers for gamma molar splits, lumping split factors, delumping, and the universal Paraffinic-Aromatic split factor S, so engineers can run screening-level characterization before moving to rigorous NeqSim Java classes. ## Core Features & Use Cases - Whitson Gamma Split: Split a plus fraction into pseudocomponents with a single controllable alpha factor, returning per-pseudocomponent mole fractions and average molar masses. - Lumping and Delumping: Compute split factors from a detailed reference fluid and reconstruct detailed compositions from lumped ones with mole conservation. - Universal P/A Split Factor S: Divide heavy lumps into paraffinic and aromatic copies using a constant or MW-interpolated split factor, including a C7+ molecular-weight screening correlation. - Use Case: Given a reservoir fluid with 5% C7+ at 220 g/mol, split it into four pseudocomponents with alpha = 1.0, then map the result onto a universal P/A component set for process simulation. ## Quick Start Ask the AI to split a C7+ plus fraction of 0.05 with molar mass 220 g/mol into four pseudocomponents using the gamma split with alpha 1.0 and eta 90.

Frequently Asked Questions about neqsim-pseudocomponent-split-characterization

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I split a C7+ plus fraction into pseudocomponents in Python?▼

Call gamma_mole_split with the plus-fraction mole fraction, average molar mass, increasing molar-mass boundaries, and a split factor alpha. It returns per-pseudocomponent mole fractions summing to z_plus and their average molar masses based on the Whitson gamma distribution.

How to delump a lumped composition back to detailed components?▼

First compute split factors from a detailed reference fluid with calculate_split_factor and a lumping scheme, then call delump_composition with the lumped composition and those factors. Each lump value is multiplied by its component split factors, reconstructing the detailed composition.

What is the universal Paraffinic-Aromatic split factor S?▼

S is the paraffinic fraction of each heavy lump in the Uleberg 2026 universal characterization, dividing lump total Z into P = S*Z and A = (1-S)*Z. A constant S can be estimated from C7+ molecular weight via the screening correlation S = 1.3298 - 0.003531 * MW.

Does this skill require NeqSim or other dependencies?▼

No, the Python helpers are dependency-free and use only the standard library. For design-grade characterization, the documentation points to the NeqSim Java classes in neqsim.thermo.characterization such as PlusFractionModel and LumpingModel.

What are the limitations of the gamma split characterization?▼

The gamma split and split factors are screening-level only; they do not tune an EOS, set critical properties, or guarantee phase-behavior accuracy. Results require review by a qualified PVT engineer before design or operational use.