Dewatering Pigging Frequency For Oil & Gas Pipelines Modified Approach

Abstract ADCO operates ~165 nos of piggable Oil & Gas pipelines extending over 2500KM. These pipelines transport produced Oil & Gas fluids from RDS, RMS`s to CDS at each interior based Assets and later the treated Oil & Gas is transported to export, distribution terminals with in UAE. The age of these pipelines is in the range 2 to 50 yrs. The dewatering pigging activity is performed on critical piggable Oil & Gas pipelines at specified regular intervals towards removing the stagnant corrosive water, debris from the bottom of the pipelines, thereby improving the performance of internal corrosion management systems. With the aging of reservoirs associated with implementation of enhanced oil recovery techniques such as water injection, Gas injection etc., the BS&W levels & GOR levels are increasing day by day with the produced crude oil. This has led to high fluid velocity in many operating oil transfer lines. There is no industry standard and or code of practice available for deciding the de-watering pigging frequency for the pipelines. In view of risks associated with pipeline pigging activities, production deferments associated with pipeline pigging activity with the high flow rate pipelines and the requirement for enhancing the efficiency of internal corrosion mitigation systems, an optimized structured semi-quantitative risk based approach is developed for identifying the optimal pigging frequency for piggable Oil & Gas pipelines based on pipeline throughput, integrity status & operating conditions.