This page provides an overview of the Subpart W reporting requirements for the well venting for liquids unloading source type. 

Please see Reporting Form Instructions on downloading the blank reporting form and uploading the completed reporting form.
You may also refer to Optional Calculation Spreadsheet Instructions to download the Subpart W calculation spreadsheet.

The well venting for liquids unloading source type is applicable to Onshore petroleum and natural gas production facilities (98.236(a)(2)).

Indicate if the facility has the source type via the radio buttons.

If the source type is present you must report the required elements.

If the facility has the source type, then indicate whether missing data procedures were used.

Reporting Requirements

Table F.1 Calculation Method 1 (counts, time, emissions)

For Sub-basins using Calculation Method 1, complete Table F.1. 
(Note: well-specific information for wells with liquids unloading must be reported in Table AA.1.iii)

• Sub-basin ID [98.236(f)(1)(i)] - the pick list for this data element is populated based on the (aa)(1) Onshore Production tab of the Smart Form.  Be sure a valid Sub-basin ID is used.
• Tubing diameter group/pressure group [98.236(f)(1)(ii)]

• Were Plunger Lifts used? [98.236(f)(1)(iii)]

• Number of wells vented for liquids unloading [98.236(f)(1)(iv)]

• Percentage of wells for which the monitoring period used to determine the cumulative amount of time venting was not the full calendar year [98.236(f)(1)(v)]

• Cumulative amount of time wells were vented, Sum of Tp Values (hours) [98.236(f)(1)(vi)]

• Cumulative number of unloadings vented [98.236(f)(1)(vii)]

• Annual natural gas emissions from well venting for liquids unloading (standard cubic feet) [98.236(f)(1)(viii)]

• Annual total CO₂ emissions [98.236(f)(1)(ix)]
• Annual total CH₄ emissions [98.236(f)(1)(x)]

Table F.1 Calculation Method 1 (counts, time, emissions)

Enlarged View of Table F.1 Calculation Method 1 (counts, time, emissions)

Enlarged View of Table F.1 Calculation Method 1 (counts, time, emissions) (continued)

Table F.2 Calculation Method 2 & 3 (with or without plunger lifts)

For Sub-basins using Calculation Method 2 (without plunger lifts) and Calculation Method 3 (with plunger lifts), complete following table:
(Note: well-specific information for wells with liquids unloading must be reported in Table AA.1.iii.)

• Sub-Basin ID [98.236(f)(2)(i)] - the pick list for this data element is populated based on the (aa)(1) Onshore Production tab of the Smart Form.  Be sure a valid Sub-basin ID is used.

• Calculation Method [98.236(f)(2)(ii)]

• Were Plunger Lifts used? [98.236(f)(2)(iii)]

• Number of wells vented for liquids unloading [98.236(f)(2)(iv)]

• Cumulative number of unloadings vented to the atmosphere [98.236(f)(2)(v)]

• Annual natural gas emissions from well venting for liquids unloading (standard cubic feet) [98.236(f)(2)(vi)]

• Total CO₂ Emissions (mt CO2) [98.236(f)(2)(vii)]

• Total CH₄ Emissions (mt CH4) [98.236(f)(2)(viii)]

• Average internal casing diameter, (inches)  [98.236(f)(2)(ix)]  (for Calc. Method 2 only)

• Average internal tubing diameter, (inches) [98.236(f)(2)(x)] (for Calc. Method 3 only)

Table F.2 Calculation Method 2 & 3 (with or without plunger lifts)

Enlarged View of Table F.2 Calculation Method 2 & 3 (with or without plunger lifts)

Enlarged View of Table F.2 Calculation Method 2 & 3 (with or without plunger lifts)(continued) 

Table F.3 Missing data procedures used for Liquids Unloading emission calculations

If your facilities relied on missing data procedures to develop data elements used in calculating emissions for well venting for liquid unloading please report the following:

• Sub-Basin ID [98.236(f)(1)(i)] - the pick list for this data element is populated based on the (aa)(1) Onshore Production tab of the Smart Form.  Be sure a valid Sub-basin ID is used.

• Tubing Diameter Group/Pressure Group for Calculation Method 1 [98.236(f)(1)(ii)]

• Parameters (specify only one per row)

  • Calculation Method 1 (counts, time, emissions) [Table F.1]

  • Calculation Method 2 & 3 (With and without plunger lifts) [Table F.2]

• Measurement Frequency

• Number of quarters missing data procedures were used [98.236(bb)(1)] (required only if the measurement frequency was quarterly)

• Total number of hours in the year missing data procedure was used [98.3(c)(8)], [98.236(bb)(2)] (required unless the measurement frequency was quarterly, annually, biannually, or N/A)

• Procedures used for missing data [98.235(h)]

Table F.3 Missing data procedures used for Liquids Unloading emission calculations

Enlarged View of Table F.3 Missing data procedures used for Liquids Unloading emission calculations

Enlarged View of Table F.3 Missing data procedures used for Liquids Unloading emission calculations (continued) 

Well–Specific Information - In addition to completing Tables F.1 – F.3, as appropriate, complete Table AA.1.iii with well-specific activity data for each well venting for liquids unloading (Tab (aa)(1) Onshore Production in the Smart Form) - see Onshore Production Facility Level Requirements.

Total Emissions

The total emissions roll-up at the top of the sheet reflects the sum of each gas emission reported for the source type. These summations are calculated automatically by the Smart Form and tabulated on the Introduction tab.