ComboCurve v35 - Compositional Economics

Feature Description: ComboCurve now supports the ability to break out the inlet gas stream into components for economic analysis & reporting.

Where: Setup is managed in Stream Properties and Pricing Econ Models – Advanced Views.

Why: Official or forecasted plant data can be used to gain a better picture of Gas Shrink, NGL yields by component, and enable a new level of accuracy in economic reporting to your gas phase per well or by asset, with an easy & intuitive setup!

 

Stream Properties

1. Open Stream Properties Advanced View & hit ‘+  Compositional’

2. These 4 lines across 2 tables will be automatically created

        Stream Properties Table: Auto-creation of both Gas Shrink & BTU conversion lines that derive ‘From Comp’ – the bottom table.

       Compositional Table: An initial ‘Remaining’ line and a Subtotal line that sums up all component lines above it.

3. The Remaining line & additional Compositional line for each desired component are how the component mixture is created.

Component Table

Above is a completed setup of a Component table.

User selects a unique component Category for each line, the Yield Source (Calculated or Manual), and inputs the Mol%. All other inputs vary based on the Yield Source Selection

Manual: User manually inputs the Yield, while Plant Efficiency, Shrink, + Post Extraction % are calculated per component

Calculated: User inputs the component’s Plant Efficiency. Yield, Shrink, and Post Extraction % are calculated

Mol % - user input, often gathered from a plant statement or other assumptions

Gal/lb-mol Factor & BTU content per component - auto-populated based on industry standard by component with a manual override at user discretion

Plant Efficiency % - represents amount of the component converted from gas to liquids during plant processing.

Shrink - the new Mol % of each component remaining as a gas, post plant operations. It is the product of the remaining gas not converted to liquids (1 – Plant Eff %) and the component’s original Mol%

Post Extraction % - takes the new resulting gaseous mixture based on component Shrink, and converting these numbers into new percentages based on the aggregated Subtotal Shrink

The subtotal line will automatically be aggregated and has multiple uses. These include:

            -Used for calculations (Subtotal shrink used in the component post extraction %)

            -Used to check numbers and true up component data (Mol %, Yield, BTU as a weighted avg.)

            -Used to report certain quantities on the main Stream Properties table (Shrink, BTU)

Remaining line – not required. It can be utilized to focus on certain components and put blanket assumptions on the rest of the gas stream. Remaining is always a Manual Yield Type (user inputs yield)

Additional Setup Notes

When using Compositional Economics – it is NOT recommended to initialize an NGL Yield line in the Stream Properties table.

NGL Yield can only be sourced from Shrunk or Unshrunk gas contents – the user could be setting up Double Dipping of NGL extraction.

When using Compositional Economics, all liquid yields are specified in the Comp table and are treated separately from gas components at this point in the workflow.

Pricing

‘Category’ column controls component assignment, the ‘+ Key’ is how additional lines are added. Like regular pricing, Criteria/Period is where the Pricing Time Series is set up.

Gas Pricing:

•       Full Stream can price gas regularly even with Comp Econ, will take stream post-shrink

•       Gas Full Stream + Gas Component Pricing can lead to double dip on revenues

•       Remaining acts like a catch-all in Pricing, can be used as price model for ALL components not explicitly defined through the price model

NGL Pricing:

•       Full Stream NGL looks specifically to the base Stream Properties table. If Comp Econ is utilized, this will result in 0 NGL revenue

•       For NGLs, it is required to define component lines or a Remaining line to have the Pricing model reference the Compositional Econ table

Compositional Economics does not currently exist in the Differentials or Expenses module, so these Compositional Pricing inputs should represent the net/realized component value, including negative values to model expenses.

Scenario Output Columns

New Compositional Economics columns were added to be selected for viewing in the Oneline & Monthly Scenario outputs. These are all added to a new section in the Columns tab

Each component’s columns includes Volumes, Revenue, & Realized Price for both Gas & NGL phase

These columns can also be selected for customized CSV/PDF building to display compositional results as you see fit!

Appendix – Gas & NGL Processing

The following section will explain how the flow of Gas and NGL streams in ComboCurve works, so that this helps the user gain a better understanding of the economics engine.

Inlet Gas (mmcf or mmbtu) is the quantity of gas that feeds into the Compositional Economics table/econ model, or the NGL Yield allocation. It is the result of taking the Gross Gas Produced for the well(s) derived from the well forecast, and accounting for both Gas Loss & Gas Flared (% remaining quantities in the Stream Properties table).

This inlet gas can be broken out in 2 different ways now. The NGL yield is now derived from the inlet gas through either the NGL Yield key in the main Stream Properties table, or the Compositional Economics table. Therefore, it is important to not use both methods to avoid double-dipping NGLS. Shrink of the gas phase coincides with NGL yields, as this volume reduction is due to the NGL extraction process. Through Stream Properties, this must be manually keyed in, using Compositional Economics, this is calculated.

If your working gas units up to this point were in MMBtu, then a BTU Content conversion is also needed in the Stream Properties table. Like Gas Shrink, this is also initialized when using Compositional Economics, and must be manually keyed in when using the legacy method. This conversion is for shrunk gas, but a second unshrunk gas BTU Content conversion can be keyed in if the user wishes to calculate Gas Variable Expenses on Unshrunk Gas.

After these Stream Properties are taken into account, these quantities are fed through pricing, and the final result is Gross Gas/NGL/Component Sales ($/bbl, $/mmcf, etc.)