ComboCarbon: Carbon Network Overview

ComboCarbon: Carbon Network Overview

Modeling Basics 
Carbon networks are composed of nodes and edges. Each node represents a point where a calculation occurs in the network, while edges indicate which nodes are related and what time series data is passed from node to node.  Some nodes represent physical pieces of equipment (pneumatic devices, compressors, etc.) while others represent activities that occur within equipment or on well pads that result in greenhouse gas emissions (liquids unloading, etc.). 


Nodes

Well Group

The Well Group node serves as the starting point for a carbon network so at least one node is required in each network. In a Well Group node, a user adds wells and assigns a fluid model.

Wells 

Assign wells to a well group using the “ADD WELLS” button.  Wells assigned to the same Well Group node will be modeled with the same emissions inputs. Wells can be added to one or more Well Group node in a given Network. Click the “VIEW/REMOVE WELLS” button to view the wells already added to a Well Group node or remove them.

The monthly production and forecasted volumes for the wells in a well group will be passed to any nodes attached to the Well Group node and used to calculate emissions based on oil or gas volumes.  Those emissions will then be assigned back to the wells. 

Fluid Model 

Assign a fluid model to the node.  All wells in the node will be assigned the composition for the designated fluids and all edges leaving the node will inherit the node’s fluid model.  See the Fluid Model section for more information. 

Drilling

The Drilling node is used to calculate combustion emissions from the drilling rig.  The following fields are used to create a temporary time series for fuel usage for each well in a connected Well Group node.
  1. Fuel Type: Type of fuel (energy) used to power drilling equipment, which determines applicable emission factors to use. Fuel types and emission factors come from the EPA. Default is Petroleum products: distillate fuel oil No. 2 (aka Diesel).
  2. Start Date Window: A date range to compare to the Start Criteria to determine which row to apply to a given well. Only one row in a node will be applied to a well. Use this field to model a change in operations for a given rig, such as a change in daily consumption rate or drilling duration
  3. Consumption Rate: Daily usage of the fuel in units depending on the fuel type chosen.
    1. Solid: short tons (TN)
    2. Liquid: gallons (GAL)
    3. Gaseous: standard cubic feet (SCF)
    4. Electricity: megawatt-hours (MWH)
  4. Start Criteria: Reference for starting the time series relative to each well.
    1. FPD (Default): First production date of the well, source determined from the Dates model
    2. From Schedule: Use a date specified in a Schedule
    3. From Headers: Use a date specified in Well Headers
  5. Start Criteria Option (used if Start Criteria is From Schedule or From Headers): A list of possible date headers from either Schedules or Well Headers. If the selected header is undefined for a well then emissions will not be calculated for that well.
  6. Start Value (used if Start Criteria is FPD): Number of days in relation to Start Criteria to start the time series. Negative numbers indicate days before the Start Criteria while positive numbers indicate days after.
  7. End Criteria: Reference for ending the time series.
    1. Duration (Default): relative time from the Start Criteria
    2. FPD: First production date of the well, source determined from the Dates model
    3. From Schedule: Use a date specified in a Schedule
    4. From Headers: Use a date specified in Well Headers
  8. End Criteria Option (used if End Criteria is From Schedule or From Headers): A list of possible date headers from either Schedules or Well Headers. If the selected header is undefined for a well then emissions will not be calculated for that well.
  9. End Value (used if End Criteria is Duration or FPD): Number of days in relation to End Criteria to end the time series. Must be assigned such that the end date comes after the start date for the time series.
Emissions from this node are recorded with emission type combustion, unless Electricity is chosen as the Fuel Type, in which case the emission type is recorded as electricity.

Completion

The Completion node is used to calculate combustion emissions from the completion rig or fleet.  The following fields are used to create a temporary time series for fuel usage for each well in a connected Well Group node.
  1. Fuel Type: Type of fuel (energy) used to power completion equipment, which determines applicable emission factors to use. Fuel types and emission factors come from the EPA. Default is Petroleum products: distillate fuel oil No. 2 (aka Diesel).
  2. Start Date Window: A date range to compare to the Start Criteria to determine which row to apply to a given well. Only one row in a node will be applied to a well. Use this field to model a change in operations for a given rig or fleet, such as a change in daily consumption rate or completion duration
  3. Consumption Rate: Daily usage of the fuel in units depending on the fuel type chosen.
    1. Solid: short tons (TN)
    2. Liquid: gallons (GAL)
    3. Gaseous: standard cubic feet (SCF)
    4. Electricity: megawatt-hours (MWH)
  4. Start Criteria: Reference for starting the time series relative to each well.
    1. FPD (Default): First production date of the well, source determined from the Dates model
    2. From Schedule: Use a date specified in a Schedule
    3. From Headers: Use a date specified in Well Headers
  5. Start Criteria Option (used if Start Criteria is From Schedule or From Headers): A list of possible date headers from either Schedules or Well Headers. If the selected header is undefined for a well then emissions will not be calculated for that well.
  6. Start Value (used if Start Criteria is FPD): Number of days in relation to Start Criteria to start the time series. Negative numbers indicate days before the Start Criteria while positive numbers indicate days after.
  7. End Criteria: Reference for ending the time series.
    1. Duration (Default): relative time from the Start Criteria
    2. FPD: First production date of the well, source determined from the Dates model
    3. From Schedule: Use a date specified in a Schedule
    4. From Headers: Use a date specified in Well Headers
  8. End Criteria Option (used if End Criteria is From Schedule or From Headers): A list of possible date headers from either Schedules or Well Headers. If the selected header is undefined for a well then emissions will not be calculated for that well.
  9. End Value (used if End Criteria is Duration or FPD): Number of days in relation to End Criteria to end the time series. Must be assigned such that the end date comes after the start date for the time series.
Emissions from this node are recorded with emission type combustion, unless Electricity is chosen as the Fuel Type, in which case the emission type is recorded as electricity.

Flowback

Used to calculate emissions during the flowback period after a well is brought online but is not connected to a production facility. The following fields are used to create a temporary time series for the volume of gas emitted during flowback for each well in the Well Group node.
  1. Start Date Window: A date range to compare to the Start Criteria to determine which row to apply to a given well. Only one row in a node will be applied to a well. Use this field to model a change in flowback operations with time, such as a change in flowback rate or flowback duration.
  2. Flowback Rate: Daily volume of gas emitted, in thousand standard cubic feet per day (MCF/D).
  3. Start Criteria: Reference for starting the time series relative to each well.
    1. FPD (Default): First production date of the well, source determined from the Dates model
    2. From Schedule: Use a date specified in a Schedule 
    3. From Headers: Use a date specified in Well Headers 
  4. Start Criteria Option (used if Start Criteria is From Schedule or From Headers): A list of possible date headers from either Schedules or Well Headers. If the selected header is undefined for a well then emissions will not be calculated for that well.
  5. Start Value (used if Start Criteria is FPD): Number of days in relation to Start Criteria to start the time series. Negative numbers indicate days before the Start Criteria while positive numbers indicate days after.
  6. End Criteria: Reference for ending the time series.
    1. Duration (Default): relative time from the Start Criteria
    2. FPD: First production date of the well, source determined from the Dates model
    3. From Schedule: Use a date specified in a Schedule 
    4. From Headers: Use a date specified in Well Headers 
  7. End Criteria Option (used if End Criteria is From Schedule or From Headers): A list of possible date headers from either Schedules or Well Headers. If the selected header is undefined for a well then emissions will not be calculated for that well.
  8. End Value (used if End Criteria is Duration or FPD): Number of days in relation to End Criteria to end the time series. Must be assigned such that the end date comes after the start date for the time series. 
To complete the emissions calculations, at least one output gas stream edge from the Flowback node must be connected to an Atmosphere or Flare node. 

Emissions from this node are recorded with the emission type based on the emission node that is downstream of this node: vented emissions for an Atmosphere node, or flared emissions for a Flare node. 

Atmosphere 

The Atmosphere node identifies vented emissions for activities where gas can either be vented or flared. Connect a gas stream to this node. 

Capture

The Capture node identifies captured emissions for activities such as carbon capture, sequestration, and underground storage. Connect a gas stream to this node. Emissions are calculated with the same methodology as the Atmosphere node but with a -1 multiplier.

Econ Output

The Econ Output node indicates the oil, gas, and water volumes that are leaving the network and will be used in economic calculations. Note: This feature has not been implemented yet, so the Econ Output node does not serve any function in the current version. This functionality is planned for a future version.

Oil Tank 

The Oil Tank node is used to model flash gas emissions from atmospheric storage tanks.  It has one input (oil stream) but two outputs (oil and gas streams).  The output gas stream is defined by the input oil stream and the following inputs within the node: 
  1. Flash Gas Ratio: The volume of gas (in units of MCF) that are liberated from one barrel of oil entering the tanks. 
  2. Fluid Model: Flash gas will have a different gas composition than the gas produced by the well, therefore a new fluid model must be assigned to this node. 
To complete the emissions calculations, at least one output gas stream edge from the Oil Tank node must be connected to an Atmosphere or Flare node. 

Emissions from this node are recorded with the emission type based on the emission node that is downstream of this node: vented emissions for an Atmosphere node, or flared emissions for a Flare node. 

Flare

The Flare node is used to perform combustion calculations on one or more input gas streams.  The emissions calculated in the Flare node will be assigned the node type of the node immediately upstream of the Flare node. The Flare node uses the gas volumes and fluid models (CO2 and C1-C5) from the input gas stream along with the following inputs within the node to calculate flared emissions: 
  1. Flare Efficiency (Default 98%): The destruction efficiency of the flare. 
  2. Flare Unlit (Default 0%): The percentage of time that the flare was not lit while gas was sent to it. 
  3. Fuel HHV: The higher heating value of the gas combusted in the flare in units of million British thermal units per standard cubic feet (MMBtu/scf). This determines the amount of nitrous oxide (N2O) emitted during combustion. The default value provided is from the EPA. 

Liquids Unloading 

The Liquids Unloading node designates the emissions that are associated with liquids unloading activities from gas wells in the network.  To complete the emissions calculations, at least one output gas stream edge from the Liquids Unloading node must be connected to an Atmosphere or Flare node. 

Emissions from this node are recorded with the emission type based on the emission node that is downstream of this node: vented emissions for an Atmosphere node, or flared emissions for a Flare node. 

Associated Gas 

The Associated Gas node designates the emissions that are recorded as associated gas from oil wells in the network.  To complete the emissions calculations, at least one output gas stream edge from the Associated Gas node must be connected to an Atmosphere or Flare node. 

Emissions from this node are recorded with the emission type based on the emission node that is downstream of this node: vented emissions for an Atmosphere node, or flared emissions for a Flare node. 

Custom Calculation 

The Custom Calculation node is used to model emissions from sources and methodologies that are specific to the user and that user would want to code in their specific formula for the emission calculation. Examples of these could be modeling emissions for non-EPA sources such as water tank emissions, Scope 3 emissions, assist gas flare, etc. The custom node requires definition of inputs (optional) and outputs: 
  1. Input: 3 options (oil, gas, water) to assign:
    1. Oil creates an input port that can be connected to oil edges as an input to the node.
    2. Gas creates an input port that can be connected to gas edges as an input to the node.
    3. Water creates an input port that can be connected to water edges as an input to the node.
    4. If no input is assigned to a node, a link edge is available to establish connection between the node and a well group node in a network. 
  2. Output: 5 options to assign to create an output for the node. For each output when assigned, a formula box is shown to input the custom calculation formula.
    1. Gas output creates an output port that can be used to connect to other nodes. The Emission Category can be defined for the gas stream, but the Emission Type will be defined in the next node. Gas output is only available to assign when there is at least 1 input assigned.
    2. CO2e creates a direct emission calculation in CO2e in Metric Tons per month with the choice of Emission Type and Category. CO2e cannot be used with any combination of individual gases (CO2, CH4, N2O)
    3. CO2 creates a direct emission calculation for CO2 in Metric Tons per month with the choice of Emission Type and Category.
    4. CH4 creates a direct emission calculation for CH4 in Metric Tons per month with the choice of Emission Type and Category.
    5. N2O creates a direct emission calculation for N2O in Metric Tons per month with the choice of Emission Type and Category. 
  3. Formula: user can compose a formula for each output using allowed algebraic functions:
    1. “USE” in the input table inserts the input into the highlighted formula
    2. “+”, “-“, “*”, “/”, “(“, “)” inserts the algebraic functions in the highlighted formula
    3. “@FPD” (only available when at least 1 input is assigned) inserts @FPD in the formula which designates the emission only occurs at the first production date.  For example, @FPD(10) will only assign 10 units of chosen output at the month encompassing the first production date.
    4. A formula can also be entered directly using exact case-sensitive rules above. 
  4. Fluid model: When a gas output is assigned, the fluid model needs to be chosen to define the composition of the exiting gas stream. 

Facility Node 

A Facility node is a special type of node that contains one or more nodes within it. The Facility node is used for three main reasons: 
  1. Simplify Carbon Networks by using one node to represent many 
  2. Quickly build networks using previously built facility templates 
  3. Model emissions from sources that do not require well volumes as inputs to the emission calculations.
The following nodes can only be added to Facility nodes.  For each of these nodes, emissions are calculated on an annual basis and then allocated on a monthly basis (based on the number of days in each month) amongst the active wells that are associated with this Facility node in the Carbon Network. 

Combustion 

The Combustion node is used to model emissions from fuel sources that power stationary equipment at a well pad or production facility. Examples of these types of equipment include generators, compressor engines, and heater treater burners.  The following inputs are required to calculate emissions from this equipment: 
  1. Criteria: Indicates whether inputs are changing or constant.
    1. Flat (Default): Emission inputs are constant from As of Date to Econ Limit for this node
    2. Dates: Emission inputs change at a specified date 
  1. Fuel Type: Type of fuel (energy) used, which determines applicable emission factors to use. Fuel types and emission factors come from the EPA. Default is Petroleum products: distillate fuel oil No. 2 (aka Diesel). 
  2. Consumption Rate: Annual usage of the fuel in units depending on the fuel type chosen. 
    1. Solid: short tons (TN) 
    2. Liquid: gallons (GAL) 
    3. Gaseous: standard cubic feet (SCF) 
    4. Electricity: megawatt-hours (MWH) 
Emissions from this node are recorded with emission type combustion, unless Electricity is chosen as the Fuel Type, in which case the emission type is recorded as electricity. 

Pneumatic Devices

The Pneumatic Device node calculates emissions from pneumatic devices that use natural gas for their operation.  The emission calculation uses an emission factor based on the operation method of the pneumatic devices, as defined by the EPA: continuous high bleed, continuous low bleed, or intermittent bleed.  The following inputs are required to calculate emissions from these devices: 
  1. Criteria: Indicates whether inputs are changing or constant.
    1. Flat (Default): Emission inputs are constant from As of Date to Econ Limit for this node
    2. Dates: Emission inputs change at a specified date 
  1. Fluid Model: The percentage of carbon dioxide and methane in the natural gas used to operate the devices 
  2. Device Type: One of High Bleed, Intermittent, or Low Bleed. Determines which emission factor to use. 
  3. Count: The number of this type of pneumatic device to model 
  4. Runtime: The average annual runtime (in hours) that a device is operating 
Emissions from this node are recorded with emission type vented. 

Pneumatic Pumps 

The Pneumatic Pump node calculates emissions from pneumatic pumps that use natural gas for their operation.  The emission calculation uses an emission factor as defined by the EPA.  The following inputs are required to calculate emissions from these pumps: 
  1. Criteria: Indicates whether inputs are changing or constant.
    1. Flat (Default): Emission inputs are constant from As of Date to Econ Limit for this node
    2. Dates: Emission inputs change at a specified date 
  1. Fluid Model: The percentage of carbon dioxide and methane in the natural gas used to operate the pumps 
  2. Count: The number of pneumatic pumps to model 
  3. Runtime: The average annual runtime (in hours) that a pump is operating 
Emissions from this node are recorded with emission type vented. 

Centrifugal Compressors

The Centrifugal Compressor node is used to model emissions from typical operations of centrifugal compressors, including events such as wet seal degassing and blowdowns.  The emission calculation uses an emission factor as defined by the EPA.  The following inputs are required to calculate emissions from these compressors: 
  1. Criteria: Indicates whether inputs are changing or constant.
    1. Flat (Default): Emission inputs are constant from As of Date to Econ Limit for this node
    2. Dates: Emission inputs change at a specified date 
  1. Count: The number of centrifugal compressors to model 
  2. Runtime: The average annual runtime (in hours) that a compressor is operating 
Emissions from this node are recorded with emission type vented. 

Reciprocating Compressors 

The Reciprocating Compressor node is used to model emissions from typical operations of reciprocating compressors, including rod packing and blowdown vents.  The emission calculation uses an emission factor as defined by the EPA.  The following inputs are required to calculate emissions from these compressors: 
  1. Criteria: Indicates whether inputs are changing or constant.
    1. Flat (Default): Emission inputs are constant from As of Date to Econ Limit for this node
    2. Dates: Emission inputs change at a specified date 
  1. Count: The number of reciprocating compressors to model 
  2. Runtime: The average annual runtime (in hours) that a compressor is operating 
Emissions from this node are recorded with emission type vented. 

Node Models

Node Models provide a way to define node parameters at the project level and then quickly assign them to nodes in a network.  Upon editing a Node Model, all networks or facilities that use that node model will be updated with the new parameters.

Creation

Node Models can be created or edited in either the Node Models tab in the Carbon Network module, or directly in the node dialog when editing a Network or Facility. Simply provide a name in the “New Model Name” box and click “SAVE AS” to create a new Node Model or “SAVE” to update an existing model.  Node Model names must be unique for each model of a given node type in each project.

Node Models can be created for any node that has editable parameters. The applicable node types are:
• Well Group
• Drilling
• Completion
• Flowback
• Flare
• Oil Tank
• Combustion
• Pneumatic Device
• Pneumatic Pump
• Centrifugal Compressor
• Reciprocating Compressor
• Custom Calculation

The node types that do not allow Node Models are:
• Atmosphere
• Capture
• Econ Output
• Liquids Unloading
• Associated Gas

Assignment

Node models can be assigned to a node when editing a Network or Facility. After dragging a node from the left panel onto the drawing canvas, right click or select the pencil icon to edit the node parameters. Any existing Node Models for that node type will be displayed in the left panel, sorted by the most recent edit date. A check mark will appear next to a Node Model name if it is already assigned to the current node. Click on one of the Node Models to view the parameters. 
There are several actions that can be taken from the Node Dialog page:
• Assign selected model to the current node: Click “APPLY”
• Edit selected model before assigning: Edit the parameters and then click “SAVE” and “APPLY”
• Create a new model before assigning: Edit the parameters, provide a name in the “New Model Name” field and then click “SAVE AS” and “APPLY”
• Input node parameters without using a node model: Type the model parameters directly and then click “APPLY”
• Use the current parameters from a Node Model but not allow the parameters in the current node to change when the Node Model is edited or deleted: Select the “Use Static Parameters” checkbox before clicking “APPLY”
REMEMBER: Editing a Node Model will affect all Networks and Facilities that use that Node Model.  Editing a Custom Calculation Node Model by changing the inputs or outputs will remove any edges connected to that Custom Calculation node that are no longer valid.

Node Display Name

All Node Dialogs contain a Node Display Name field. By default, this field is blank, and the node type is displayed below the node (or above for Well Group nodes) when viewing a Network or Facility. If a Node Model is assigned to a node, then the Node Model Name will be displayed instead. If a user does not want to display the node type or the Node Model Name, then a name can be provided in the Node Display Name field. This name does not have to be unique.

See the Export and Import sections below for how Node Models are exported and how they can be created, edited, and assigned during import.

Edges 

Edges are used to connect nodes in a network and transfer information between them.  Nodes may only be connected if they have an output port and an input port of the same color.  However, more than one edge can leave one output port and more than one edge can enter an input port. 

There are four types of edges within a Carbon Network: 

Stream Edges 

Stream edges connect two nodes and transfer time series data for an oil, gas, or water stream.  Stream edges require an output port and an input port of the same color to successfully connect two nodes. When a Stream edge is created between two nodes, there is an option to modify the time series data transferred from the upstream node to the downstream node via a multiplier, known as the Allocation Ratio. By default, the Allocation Ratio is 100%, but the user can edit this value to scale up or scale down the volumetric time series data transferred to a node.  The behavior of the Allocation Ratio is determined by the Criteria specified in the edge:
  1. Criteria: Indicates whether Allocation Ratio is changing or constant.
    1. Flat (Default): Allocation Ratio is constant from As of Date to Econ Limit for this edge
    2. Dates: Allocation Ratio changes at a specified date


Dev Edges

Dev edges connect Development nodes to Well Group nodes.  Development nodes include Drilling and Completion nodes, which represent the development of wells prior to production.  A Dev edge does not have an Allocation Ratio because it only conveys the association between Development and Well Group nodes for the purposes of calculating and reporting emissions back to the wells in the Well Group node.


Facility Edges 

Facility edges are stream edges that are only attached to a node at one end. They are used to create the Input and Output ports of a Facility node.  The Input edge only connects to the Input port of a node inside the Facility node. The Output edge only connects to the Output port of a node inside the Facility node.  Facility edges start without a stream color when they are added to a Facility node model. When they are connected to the required port within the model, the color changes to match the connected port. 

Facility edges do not have an Allocation Ratio because they are representations of ports rather than edges in the Carbon Network.  Facility edges can be renamed to make it clear which port to use when the Facility node is represented in a Carbon Network. 

 


It is possible to create a Facility node that does not contain any nodes that have Input ports. In this case, an Input Facility edge cannot be added to the Facility node, but the user still needs to associate a Facility with a Well Group node in the Carbon Network.  To accomplish this, the user can use a Link edge. 

Link edges are represented as dashed gray lines in a Carbon Network and can only be used to connect Well Group nodes to Facility or Custom Calculation nodes.  If a Facility node is saved without any Facility edges, then a Link port will be automatically created for this Facility node so that it may be connected to one or more Well Group nodes.  A Link edge does not have an Allocation Ratio because it only conveys the association between Facility and Well Group nodes for the purposes of allocating emissions from the Facility node back to the wells in the Well Group node. The same behavior applies to Custom Calculation nodes that do not have any inputs assigned.



Fluid Model 

Many emissions calculations require information about the composition of the gas that is emitted.  Fluid models are used to easily store and reference this gas composition information. The fluid model includes the following 20 components, for each of the 5 products tracked in ComboCurve.  Currently, only the composition of the gas phase is used in emissions calculations.  For vented emissions, only the carbon dioxide (CO2) and methane (C1) components are used.  For flared emissions, the carbon dioxide and hydrocarbon components up to and including pentanes (iC5, nC5) are used. See the Emission Calculations section for more information on how these components are used. 

Fluid models are initially assigned to Well Group nodes and then the information is passed via edges to the rest of the nodes in the network. All edges leaving a node will inherit the fluid model assigned in that node.  If a fluid model is not assigned in a node, the edges leaving that node will inherit the fluid model of the edge(s) that entered that node. 




Component 


Abbreviation 

Nitrogen 

N2 

Carbon Dioxide 

CO2 

Methane 

C1 or CH4 

Ethane 

C2

Propane 

C3 

Isobutane 

iC4 

Normal Butane 

nC4 

Isopentane 

iC5 

Normal Pentane 

nC5 

Isohexanes 

iC6 

Normal Hexane 

nC6 

Heptanes 

C7 

Octanes 

C8 

Nonanes 

C9 

Decanes Plus 

C10+ 

Hydrogen Sulfide 

H2S 

Hydrogen 

H2 

Water 

H2O 

Helium 

He 

Oxygen 

O2 
 

Emission Calculations 

Greenhouse Gas emission calculations vary based on the way in which the gases are emitted, ie the Emission Type. However, there is a general pattern to these calculations:

Product Volume --> GHG Volume --> GHG Mass

The conversion from a product (gas) volume to a greenhouse gas volume is based on the composition of the product stream, as defined by a gas analysis and assigned with a Fluid Model. The conversion from greenhouse gas volume to greenhouse gas mass is based on the density of each greenhouse gas, which is a standardized value. The density of carbon dioxide is 0.0526 metric tons per thousand standard cubic feet (MT/MCF). The density of methane is 0.0192 metric tons per thousand standard cubic feet (MT/MCF). Note that the densities are the same in units of kilograms per cubic foot (KG/SCF).

Vented 

A typical venting calculation is: 

Where: 
  1. 𝑀𝑖 = Mass emissions of greenhouse gas, i, in metric tons (mt) 
  2. 𝑉𝑔𝑎𝑠 = Volume of gas emitted, in thousand standard cubic feet (MCF) 
  3. 𝑌𝑖 = Mole fraction of greenhouse gas, i, in gas emitted 
  4. 𝜌𝑖 = Density of greenhouse gas, i, in metric tons per thousand standard cubic feet (mt/MCF) 
Reference equations: W-35 and W-36 from EPA Subpart W 

This calculation is used when a gas stream edge is connected to an Atmosphere node in a network. 

For emission calculations from Pneumatic Device and Pneumatic Pump nodes, the Vgas term is determined by the inputs specified in the node and an emission factor: 



Where:
  1. 𝑉𝑔𝑎𝑠,𝑡 = Volume of gas emitted from device type, t, in thousand standard cubic feet (MCF) 
  2. 𝑁𝑡 = Count of device type, t 
  3. 𝐸𝐹𝑡 = Emission factor for device type, t, in units of thousand standard cubic feet per hour per device (MCF/hr/device) 
  4. 𝑇𝑡 = Runtime of device type, t, in hours (hr) 
Reference equations: W-1 and W-2 from EPA Subpart W 
For emission calculations from Centrifugal Compressor and Reciprocating Compressor nodes, the term to calculate the greenhouse gas emitted volume (𝑉𝑔𝑎𝑠×𝑌𝑖) is determined by the inputs specified in the node and an emission factor: 


Where:
  1. 𝑉𝑖,𝑡 = Volume of greenhouse gas, i, emitted from compressor type, t, in thousand standard cubic feet (MCF)
  2. 𝑁𝑡 = Count of compressor type, t
  3. 𝐸𝐹𝑖,𝑡 = Emission factor for greenhouse gas , i, for compressor type, t, in units of thousand standard cubic feet per hour per compressor (MCF/hr/device)
  4. 𝑇𝑡 = Runtime of compressor type, t, in hours (hr) 
Reference equations: W-25 and W-29D from EPA Subpart W 

Capture

The capture calculation is:


Where:
  1. Mi = Mass emissions of captured greenhouse gas, i, in metric tons (mt)
  2. V(gas) = Volume of gas captured, in thousand standard cubic feet (MCF)
  3. Y(i) = Mole fraction of greenhouse gas, i, in gas captured
  4. ρ(i) = Density of greenhouse gas, i, in metric tons per thousand standard cubic feet (mt/MCF)
This calculation is used when a gas stream edge is connected to a Capture node in a network.

Flared 

The flare calculation uses different equations for each of the three main greenhouse gases.  The emissions of carbon dioxide and methane are based on the composition of the gas stream and the combustion efficiency of the flare, while the emissions of nitrous oxide are based on the heating value of the fuel and an emission factor.

 
Where: 
  1. MCO2 = Mass emissions of CO2 in metric tons (mt) 
  2. MCH4 = Mass emissions of CH4 in metric tons (mt) 
  3. MN2O = Mass emissions of N2O in metric tons (mt) 
  4. Vgas = Volume of gas sent to flare, in thousand standard cubic feet (MCF) 
  5. YCO2 = Mole fraction of CO2 in gas sent to flare 
  6. YCH4 = Mole fraction of CH4 in gas sent to flare 
  7. η = Flare efficiency 
  8. Yj = Mole fraction of hydrocarbon constituent, j, in gas sent to flare 
  9. Rj = Number of carbon atoms in hydrocarbon constituent, j, in gas sent to flare: 1 for methane, 2 for ethane, 3 for propane, 4 for butane, and 5 for pentanes-plus 
  10. ZU = Fraction of gas sent to unlit flare 
  11. ZL = Fraction of gas sent to lit flare (equal to 1 – ZU) 
  12. ρi = Density of greenhouse gas, i, in metric tons per thousand standard cubic feet (mt/MCF) 
  13. HHV = Higher heating value of the gas sent to flare, in units of million British thermal units per standard cubic foot (MMBtu/scf) 
  14. EF = Emission factor for N2O in units of metric tons per million British thermal units (mt/MMBtu). See Flare table in the Emission Factors
Reference equations: W-19, W-20, W-36, and W-40 from EPA Subpart W 

Combustion 

Emission calculations for combustion use emission factors for the higher heating value of the fuel and for each greenhouse gas. The combustion calculation equation is: 



 
Where: 
  1. 𝑀𝑖 = Mass emissions of greenhouse gas, i, in metric tons (mt) 
  2. 𝑉𝑓𝑢𝑒𝑙 = Volume of fuel consumed in units dependent on the fuel type: short tons (TN) for solid fuels, gallons (GAL) for liquid fuels, and standard cubic feet (SCF) for gaseous fuels 
  3. 𝐻𝐻𝑉𝑓𝑢𝑒𝑙 = Higher heating value of the fuel, in units of million British thermal units per fuel unit (MMBtu/fuel unit) 
  4. 𝐸𝐹𝑓𝑢𝑒𝑙,𝑖= Emission factor for the given fuel type and greenhouse gas, i, in units of metric tons per million British thermal units (mt/MMBtu) 
Reference equations: C-1 and C-8 from EPA Subpart C 

Electricity 

Emission calculations for electricity use emission factors for each greenhouse gas. The electricity calculation equation is: 



Where: 
  1. 𝑀𝑖 = Mass emissions of greenhouse gas, i, in metric tons (mt) 
  2. 𝐸𝑔𝑟𝑖𝑑 = Grid electricity consumed in units of megawatt-hours (MWh) 
  3. 𝐸𝐹𝑔𝑟𝑖𝑑,𝑖= Emission factor for the given grid and greenhouse gas, i, in units of metric tons per megawatt-hours (mt/MWh) 
Reference equation: Equation 1 from EPA eGRID Environmental Footprinting 

Global Warming Potentials 

According to the EPA, Global Warming Potential “is a measure of how much energy the emissions of 1 ton of a gas will absorb over a given period of time, relative to the emissions of 1 ton of carbon dioxide (CO2).” It is used to convert emissions of various greenhouse gases into a normalized metric, called “carbon dioxide equivalent” (CO2e), for comparison and aggregation.  Global Warming Potentials vary based on the time period considered and the methodology used. 

ComboCarbon uses the same Global Warming Potentials as the EPA Greenhouse Gas Reporting Program (GHGRP), which come from the Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Report (AR4) published in 2007. 




Greenhouse Gas 





100-Year Global Warming Potential (1) 

Carbon Dioxide (CO2) 

1 

Methane (CH4) 

25 

Nitrous Oxide (N2O) 

298 

(1) Source: IPCC Fourth Assessment Report 

To calculate carbon dioxide equivalent emissions, multiply the mass emissions of each greenhouse gas by its respective Global Warming Potential. 



Where: 
  1. 𝐶𝑂2𝑒𝑖,𝑠 = Carbon dioxide equivalent mass emissions of greenhouse gas, i, for emission source, s, in metric tons (mt) 
  2. 𝑀𝑖,𝑠 = Mass emissions of greenhouse gas, i, for emission source, s, in metric tons (mt) 
  3. 𝐺𝑊𝑃𝑖 = Global Warming Potential of greenhouse gas, i. 
Once emissions are converted to carbon dioxide equivalents, they can be aggregated to get the total emissions from a given source. 


Where: 
  1. CO2es = Carbon dioxide equivalent mass emissions for emission source, s, in metric tons (mt) 
  2. CO2ei,s = Carbon dioxide equivalent mass emissions of greenhouse gas, i, for emission source, s, in metric tons (mt) 
For more information, refer to the EPA’s resources for Understanding Global Warming Potentials

Emission Factors 

Emission Factors come from the EPA. 

Flare


Greenhouse Gas

Emission Factor (mt/mmBtu) (1)

Nitrous oxide

1.0 x 10^-7

(1) Original units are kg/mmBtu and are converted to mt/mmBtu using the conversion factor 1 x 10-3 mt/kg

Source: Equation W-40 from EPA Subpart W


Pneumatic Devices & Pumps 


Equipment Type 

Emission Factor (mcf/hr/device) (1) 

Low Continuous Bleed Pneumatic Device 

0.00139 

Intermittent Bleed Pneumatic Device 

0.0135 

High Continuous Bleed Pneumatic Device 

0.0373 



 

Equipment Type 

Emission Factor (mcf/hr/pump) (1)
Pneumatic Pump 
0.0133 

(1) Original units are scf/hr/device and are converted to mcf/hr/device using the conversion factor 1 x 10-3 mcf/scf 

Source: EPA Subpart W Table Table W-1A

Compressors

Equipment Type
Approximate Emission Factor (mcf/hr/compressor) (1)
 
CO2
CH4
Centrifugal Compressor
6.05023 x 10^-2
1.36986

Reciprocating Compressor

6.01598 x 10^-5

1.08219 x 10^-3
 
Actual Emission Factor (scf/yr/compressor) (2)
 
CO2
CH4
Centrifugal Compressor
5.3 x 10^5
1.2 x 10^7
Reciprocating Compressor
527
9480
(1) These are approximations of the emission factors used in ComboCarbon. Original units are scf/yr/compressor and are converted to mcf/hr/compressor using the conversion factors 1 x 10—3 mcf/scf and 8760 hr/yr.
(2) These are the original emission factors from the EPA. Use these and convert to mcf/hr/compressor if you are experiencing rounding errors when comparing ComboCarbon results to external calculations.

Sources: EPA Subpart W Section 98.233(o)(10) and Section 98.233(p)(10)


Fuels 




Fuel Type 



High Heat Value 



CO2 Emission Factor 



CH4 Emission Factor 



N2O Emission Factor 

Coal and coke 

MMBtu/short ton 

mt/MMBtu (1) 

mt/MMBtu (1)

mt/MMBtu (1)

Anthracite 

25.09 

0.10369 

1.1 x 10^-5 

1.6 x 10^-6 

Bituminous 

24.93

0.09328 

1.1 x 10^-5 

1.6 x 10^-6 

Subbituminous 

17.25 

0.09717 

1.1 x 10^-5 

1.6 x 10^-6 

Lignite 

14.21 

0.09772 

1.1 x 10^-5 

1.6 x 10^-6 

Coal Coke 

24.8 

0.11367 

1.1 x 10^-5 

1.6 x 10^-6 

Mixed (Commercial sector) 

21.39 

0.09427 

1.1 x 10^-5 

1.6 x 10^-6 

Mixed (Industrial coking) 

26.28 

0.0939 

1.1 x 10^-5 

1.6 x 10^-6 

Mixed (Industrial sector) 

22.35 

0.09467 

1.1 x 10^-5 

1.6 x 10^-6 

Mixed (Electric Power sector) 

19.73 

0.09552 

1.1 x 10^-5 

1.6 x 10^-6 

Natural gas 

MMBtu/scf 

mt/MMBtu (1) 

mt/MMBtu (1)

mt/MMBtu (1)

Natural Gas (pipeline quality) 

0.001026 

0.05306 

1.0 x 10^-6 

1.0 x 10^-7 

Petroleum products - liquid 

MMBtu/gallon 

mt/MMBtu (1) 

mt/MMBtu (1) 

mt/MMBtu (1) 

Distillate Fuel Oil No. 1 

0.139 

0.07325 

3.0 x 10^-6 

6.0 x 10^-7 

Distillate Fuel Oil No. 2 

0.138 

0.07396 

3.0 x 10^-6 

6.0 x 10^-7 

Distillate Fuel Oil No. 4 

0.146 

0.07504

3.0 x 10^-6 

6.0 x 10^-7 

Residual Fuel Oil No. 5 

0.14 

0.07293 

3.0 x 10^-6 

6.0 x 10^-7 

Residual Fuel Oil No. 6 

0.15 

0.0751 

3.0 x 10^-6 

6.0 x 10^-7 

Used Oil 

0.138 

0.074 

3.0 x 10^-6 

6.0 x 10^-7 

Kerosene 

0.135 

0.0752 

3.0 x 10^-6 

6.0 x 10^-7 

Liquefied petroleum gases (LPG) 

0.092 

0.06171 

3.0 x 10^-6 

6.0 x 10^-7 

Propane 

0.091 

0.06287 

3.0 x 10^-6 

6.0 x 10^-7 

Propylene 

0.091 

0.06777 

3.0 x 10^-6 

6.0 x 10^-7 

Ethane 

0.068 

0.0596 

3.0 x 10^-6 

6.0 x 10^-7 

Ethanol 

0.084 

0.06844 

3.0 x 10^-6 

6.0 x 10^-7 

Ethylene 

0.058 

0.06596 

3.0 x 10^-6 

6.0 x 10^-7 

Isobutane 

0.099 

0.06494 

3.0 x 10^-6 

6.0 x 10^-7 

Isobutylene 

0.103 

0.06886 

3.0 x 10^-6 

6.0 x 10^-7 

Butane 

0.103 

0.06477 

3.0 x 10^-6 

6.0 x 10^-7 

Butylene 

0.105 

0.06872 

3.0 x 10^-6 

6.0 x 10^-7 

Naphtha (<401 deg F) 

0.125 

0.06802 

3.0 x 10^-6 

6.0 x 10^-7 

Natural Gasoline 

0.11 

0.06688 

3.0 x 10^-6 

6.0 x 10^-7 

Other Oil (>401 deg F) 

0.139 

0.07622 

3.0 x 10^-6 

6.0 x 10^-7 

Pentanes Plus 

0.11 

0.07002 

3.0 x 10^-6 

6.0 x 10^-7 

Petrochemical Feedstocks 

0.125 

0.07102 

3.0 x 10^-6 

6.0 x 10^-7 

Special Naphtha 

0.125 

0.07234 

3.0 x 10^-6 

6.0 x 10^-7 

Unfinished Oils 

0.139 

0.07454 

3.0 x 10^-6 

6.0 x 10^-7 

Heavy Gas Oils 

0.148 

0.07492

3.0 x 10^-6 

6.0 x 10^-7 

Lubricants 

0.144 

0.07427 

3.0 x 10^-6 

6.0 x 10^-7 

Motor Gasoline 

0.125 

0.07022 

3.0 x 10^-6 

6.0 x 10^-7 

Aviation Gasoline 

0.12 

0.06925 

3.0 x 10^-6 

6.0 x 10^-7 

Kerosene-Type Jet Fuel 

0.135 

0.07222 

3.0 x 10^-6 

6.0 x 10^-7 

Asphalt and Road Oil 

0.158 

0.07536 

3.0 x 10^-6 

6.0 x 10^-7 

Crude Oil 

0.138 

0.07454 

3.0 x 10^-6 

6.0 x 10^-7 


Petroleum products - solid 


MMBtu/short ton 


mt/MMBtu (1) 


mt/MMBtu (1) 


mt/MMBtu (1) 

Petroleum Coke 

30 

0.10241 

3.0 x 10^-6 

6.0 x 10^-7 


Petroleum products - gaseous 


MMBtu/scf 


mt/MMBtu (1) 


mt/MMBtu (1)


mt/MMBtu (1)

Propane Gas 

0.002516 

0.06146 

3.0 x 10^-6 

6.0 x 10^-7 


Other fuels - solid 


MMBtu/short ton 


mt/MMBtu (1)


mt/MMBtu (1)


mt/MMBtu (1)

Municipal Solid Waste 

9.95 

0.0907 

3.2 x 10^-5 

4.2 x 10^-6 

Tires 

28 

0.08597 

3.2 x 10^-5 

4.2 x 10^-6 

Plastics 

38 

0.075 

3.2 x 10^-5 

4.2 x 10^-6 


Other fuels - gaseous 


MMBtu/scf 


mt/MMBtu (1)


mt/MMBtu (1)


mt/MMBtu (1)

Blast Furnace Gas 

0.000092 

0.27432 

2.2 x 10^-8 

1.0 x 10^-7 

Coke Oven Gas 

0.000599 

0.04685 

4.8 x 10^-7 

1.0 x 10^-7 

Fuel Gas 

0.001388 

0.059 

3.0 x 10^-6 

6.0 x 10^-7 


Biomass fuels - solid 


MMBtu/short ton 


mt/MMBtu (1)


mt/MMBtu (1)


mt/MMBtu (1)

Wood and Wood Residuals (dry basis) 

17.48 

0.0938 

7.2 x 10^-6 

3.6 x 10^-6 

Agricultural Byproducts 

8.25 

0.11817 

3.2 x 10^-5 

4.2 x 10^-6 

Peat 

8 

0.11184 

3.2 x 10^-5 

4.2 x 10^-6 

Solid Byproducts 

10.39 

0.10551 

3.2 x 10^-5 

4.2 x 10^-6 


Biomass fuels - gaseous 


MMBtu/scf 


mt/MMBtu (1) 


mt/MMBtu (1) 


mt/MMBtu (1)

Landfill Gas 

0.000485 

0.05207 

3.2 x 10^-6 

6.3 x 10^-7 

Other Biomass Gases 

0.000655 

0.05207 

3.2 x 10^-6 

6.3 x 10^-7 


Biomass fuels - liquid 


MMBtu/gallon 


mt/MMBtu (1) 


mt/MMBtu (1) 


mt/MMBtu (1)

Ethanol 

0.084 

0.06844 

1.1 x 10^-6 

1.1 x 10^-7 

Biodiesel 

0.128 

0.07384 

1.1 x 10^-6 

1.1 x 10^-7 

Rendered Animal Fat  

0.125 

0.07106 

1.1 x 10^-6 

1.1 x 10^-7 

Vegetable Oil  

0.12 

0.08155 

1.1 x 10^-6 

1.1 x 10^-7 

(1) Original units are kg/MMBtu and are converted to mt/MMBtu using the conversion factor 1.0 x 10—3 mt/kg 
Source: EPA Subpart C: Table C-1 and Table C-2 


Electricity


Grid 


CO2 Emission Factor 


CH4 Emission Factor 


N2O Emission Factor 

 

mt/MWh (1)

mt/MWh (1)

mt/MWh (1)

U.S. Average 

0.37117 

2.94835 x 10^-5 

4.08233 x 10^-6 

ERCOT 

0.37131 

2.35868 x 10^-5 

3.17515 x 10^-6 
(1) Original units are lb/MWh and are converted to mt/MWh using the conversion factor 4.5359237 x 10—4 mt/lb 
Source: EPA eGRID2020 Subregion Total Output Emission Rates 

Export

Export one or more networks by clicking the checkbox next to the network and selecting the “Export” button at the top of the page. This will generate an Excel file with sheets detailing the nodes and edges in each network and the parameters for each node type. Any facilities included in the selected network(s) will be included in the export. 
Three sets of information are needed to define a network or a facility: the list of nodes, the list of edges, and the parameters for the nodes. The node parameters are separated from the list of nodes because the parameters vary for each node and can not be easily represented in one excel sheet. 

Network 

The Network sheet defines the Network Name of each network and the list of nodes included in that network, with one row corresponding to one node. Each node has a unique Node ID that is autogenerated using the format {Network Name}_{Node Type}_{Node Index}. The Node ID is used as a reference on the Network Edges sheet to indicate which nodes are connected by a given edge. The Model ID references the parameters that are defined on the sheet that matches the Node Type. If the Node Type is a Facility, then the Model ID will match the Facility Name. The Node Display Name is an optional name that can be displayed when viewing nodes in a Network or Facility when the default behavior is not desired. The remaining fields are metadata fields (Project Name, Created At, Created By, Last Update, Updated By). Updated By will be populated in a future release. 

Network Edges 

The Network Edges sheet defines the edges in each network, with an edge represented by one or more rows.  Link edges, Development edges, and Stream edges with the Flat criteria will only have one row, while Stream edges with the Dates criteria will have one row for each date. Each edge has a unique Edge ID that is autogenerated using the format {Network Name}_{Edge Type}_{Edge Index}, as well as a From Node ID and a To Node ID that matches the Node IDs of nodes in the Network sheet.  If an edge is connected a Facility Node, then there will also be a From Port ID and/or a To Port ID that matches the Edge ID of an Input or Output edge in the Facility Edges sheet. 

Facility 

The Facility sheet has all the same fields as the Network sheet and serves the same purpose. 

Facility Edges 

The Facility Edges sheet serves the same purpose as the Network Edges sheet. Input edges, Output edges and Stream edges with the Flat criteria will only have one row, while Stream edges with the Dates criteria will have one row for each date. Input edges do not have a From Node ID and Output edges do not have a To Node ID. 

Wells 

The Wells sheet lists the wells that are assigned to each Well Group node.  Each row corresponds to one well in a Well Group node. The Well Group Model ID matches the Model ID field on the Well Group sheet. 

Node Sheets 

Each sheet that corresponds to a node type has metadata fields (Created At, Created By, Last Update, Updated By), common node fields (Model Name and Description) and node specific parameter fields. The Model Type field is set to “project” for parameters that come from Node Models, or “unique” for parameters that are defined directly in a node. The metadata and Model Name fields, are only populated fore Node Models included in the export. Each node has a unique Model ID that is autogenerated using the format {Node Type}_{Node Index}. The Model ID gets referenced on the Network and Facility sheets to match node parameters to a Node ID in a network or facility. 

Import 

Getting Started 

To import networks, facilities, and/or node models the selected Excel file must have all of the sheets and all of the fields on each sheet, with the exception of the metadata fields, that are included in the Export. It is strongly recommended to export a network to serve as a template for importing new or existing networks and facilities. An error message will be displayed and the import will fail if a sheet or a field is missing from the imported file.

Wells and Fluid Models must exist in the project prior to assigning them to nodes in a network, facility, or node model.  Wells get assigned based on the Well Identifier selected on the Network Import dialog.  Only the selected well identifier and the Well Group Model ID fields are required on the Wells sheet.  Fluid Models get assigned based on the name of the model. 

If an imported Network Name matches a network that already exists in the project, then the existing network will be replaced with the imported network. This is beneficial when editing an existing network that is already assigned to wells in the Scenario table. 

If an imported Facility Name matches a facility that already exists in the project, then the method of handling the facility import will be determined by the selection on the Network Import dialog. The default behavior is to Create a new facility by appending a numerical suffix “_1” to the imported facility name. If a facility with the new name already exists, then the numerical suffix will be incremented until a new facility name is created.  Alternatively, the existing facility can be Overwritten by the imported facility. With this option, any existing networks that use this facility and were not included in the import will be updated to reference the new facility.  **All Stream edges connected to the facility will be deleted as part of the update.** 

To create new or edit existing node models during import, set the Model Type field to “project”. A Model Name is required for all node models.  If an imported Model Name matches a node model of the same type in the project, then the method of handling the node model import will be determined by the selection on the Network Import dialog. The same settings and behaviors apply for duplicate node model names as for duplicate Facility names. See the paragraph above. **If importing Custom Calculation node models and the “Overwrite” method was selected, then any input or output stream edges connected to the overwritten Custom Calculation nodes will be deleted as part of the network and facility update after importing.**

Model IDs, Node IDs, and Edge IDs 

Model IDs, Node IDs and Edge IDs are temporary identifiers that are only used during a single export or import. When importing Carbon Networks, the IDs do not have to follow the format that is used in an export – this format is used simply to create identifiers that are easily readable by users.  Users should not expect the identifiers they use in an import to be preserved when exporting. 

Model IDs are used on Node sheets to group node parameters on one or more rows of a given node sheet. If the imported node has more than one row of node parameters (applicable to Drilling, Completion, Flowback, Pneumatic Device, Pneumatic Pump, Centrifugal Compressor, Reciprocating Compressor, and Custom Calculation node types), then the Model ID should be repeated on each of the rows.  For all other node types, the Model ID should be unique for each row on a given node sheet. 

Node IDs are used on the Network and Facility sheets to assign nodes to a given network or facility. Each row on a Network or Facility sheet represents one node and therefore must have a unique Node ID.  Each row must also have a Node Type and a Model ID in order to match node parameters to that node.  The Model ID on the Network or Facility sheet must match a Model ID on the sheet of the corresponding Node Type. When adding a Facility node to a Network, use the Facility Name as the Model ID. 

When defining nodes on the Network sheet or the Facility sheet, two nodes can use the same Model ID. This will create two nodes with the same parameters during the import. This is the expected behavior if importing a node model and assigning it to multiple nodes.

Edge IDs are used on the Network Edges and Facility Edges sheets to create and identify edges.  When importing a Stream edge with a Dates criteria that has more than one period, then the Edge ID should be repeated on each of the rows.  For all other edge types, the Edge ID should be unique for each row on the sheet.  To create an Input edge in a facility, provide a To Node ID that matches one of the Node IDs on the Facility Sheet but leave the From Node ID field blank. The Edge ID for this row will become the To Port ID that needs to be referenced on the Network Edges sheet when connecting a Stream edge to this facility node in the network.  The same pattern applies to an Output edge in a facility – provide a From Node ID, leave the To Node ID field blank and use the Edge ID as the From Port ID on the Network Edges sheet. 

Renaming Networks, Facilities and Node Models

The Network and Facility sheets contain New Network Name and New Facility Name fields, respectively, in the export file.  These are optional fields that can be populated if a user wants to overwrite an existing network or facility and also rename it.   This is useful if the network is assigned to wells in a Scenario table or if a facility is used in multiple networks.  If the New Network Name or New Facility Name already exists in the project, then an error report will be logged and the network or facility will not be imported. 

There is a New Name field on each of the Node sheets.  This field allows a user to overwrite an existing node model and also rename it during the import.  It is only applicable to nodes with Model Type set to “project.”

Error Handling 

Each node, node model, edge, facility and network is validated during import. Any invalid values will be logged and returned to the user in an error report.  The error report is a copy of the imported file with an Error Message column added to each sheet.  It is intended to help the user quickly identify the invalid rows or fields. 

Networks, facilities or node models that have invalid values will not be imported. If a node model fails to import and is included in any facilities or networks, then those facilities and networks will also not be imported. If a facility fails to import and is included in a network, then the network will also not be imported.  If multiple networks, facilities, and/or node models are included in an import, only the valid ones will be imported.  It is possible that it will require multiple iterations of importing, fixing invalid entries, and reimporting to successfully import all networks and facilities.  If the Create New option is selected to handle duplicate facilities and/or node models, this could inadvertently cause multiple versions of the same facility and/or node models to be imported during this iterative process.  Please keep this in mind when importing multiple facilities and/or node models in a single file. 






















































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