Abstract
This paper summarizes the pre-assessment, indirect examination (i.e. internal corrosion predictive modeling (ICPM)), detailed examination and post-assessment results of a multiphase-flow internal corrosion direct assessment (MP-ICDA). This assessment was performed using an in-house internal corrosion predictive model on a header pipeline in the Tambaredjo North West (TNW) oil field in Suriname. This pipeline has a total length of 4,801 m, with a 10 inch nominal diameter region which is 415 m long and a 14 inch nominal diameter region which is 4,386 m long carrying multiphase crude oil. There are three waterway crossings along the pipeline; widths of these crossings are approximately 40 m, 50 m, and 115 m respectively. At the crossings, the pipeline drops to an approximate depth of 2.5 meters below the surface of the water crossing and rises back to the surface after crossing the waterway. The scope of this project also included a "what-if" phase in which five possible future operational scenarios were investigated. This analysis enables the pipeline operator to predict the probable internal corrosion rate for the anticipated future operational conditions (e.g. increased water-cut, lower/higher operational pressures or temperatures, seasonal effects, further souring of the reservoir, change in the mole composition of the associated gas, etc.). Conclusions and recommendations in this paper were produced based on the fully performed DA assessment. In addition, appropriate mitigation measures were recommended to reduce the risk of internal corrosion in the subject pipeline.
