Abstract The methods available for calculating emissions in the industrial sector are limited to industry-average, supplier-specific, hybrid or spend-based emission factors (tCO2e per material purchased or tCO2e per dollar billed, respectively). This provides a high-level view of the total emissions and average CO2-e values ​​generated per drilled and completed well. However, these data are not sufficient when it is necessary to know the emissions from a specific activity such as the completion of a well, a well service, a drilling or workover rig consumption, or when it is desired to determine the reduction of emissions from the use of a technology in a specific activity. This article will present a methodology to calculate the CO2-e emission factors during the completion of injection and producer wells in different fields in Colombia. Includes an analysis of the existing literature regarding emission factors for completion operations, the description of the main emission sources in completion operations and the procedure used to obtain the emission factors by type of well (tCO2e/completed well), by completion activity (tCO2e/activity) or by type of equipment (tCO2e/equipment). The calculation methodology includes the procedure for data gathering and validation, database creation, specific CO2-e factors calculations as well as the premises considered. For the studied wells, the work identified the activities with the greatest impact on operations, the type of well with the highest emissions, and offers a comparison in terms of type of intervention equipment such as Workover Rig, drilling Rig or Coiled Tubing. Finally, a list of emission factors will be presented by type of well, by type of equipment and by specific activity.