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PIPELINE PIGGING TECHNOLOGY- P9: Why pig a pipeline? This paper introduces a number of reasons for doing so, together with a discussion of the advantages and alternatives. In general terms, however, pigging is not an operation to be undertaken lightly. There are often technical problems to be resolved and the operation requires careful control and co-ordination. | This page intentionally left blank Please purchase PDF Split-Merge on www.verypdf.com to remove this watern Pigging and. chemical treatment PIGGING AND CHEMICAL TREATMENT OF PIPELINES THE PRIMARY purposes of any pipeline-maintenance programme are to maximize flow ability and prolong the life of the piping system. The two most common procedures for internal maintenance are chemical treatment and mechanical cleaning using pigs. Although the procedures differ in nature and effect they are often used together to offer an efficient and cost-effective approach to controlling significant pipeline problems. An understanding of how each method works will give a clearer picture of how to combine the two for a more effective comprehensive pipeline-maintenance programme. INTRODUCTION Chemicals used in treating oil and gas pipelines such as pour-point depressants flow improvers corrosion inhibitors biocides and gas hydrate prevention products are often applied using pigs to enhance their performance and efficiency and to supplement their action. Pigs are used to remove paraffin deposits apply corrosion inhibitors clean deposits from the line and keep out accumulations of water. Water is the source of several problems in oil and gas pipelines in that it allows corrosion to occur and bacteria to grow. Bacteria generate hydrogen sulphide cause corrosion and produce plugging slimes and solids in the fluids. Of equal value is the ability to remove sand chalk rust and scale deposits from inside the pipeline which can cause under-deposit corrosion a major form of accelerated corrosion similar to pitting. The following sections of this paper review the use of pigs in applying the chemicals used to treat pipelines with an explanation of the purpose of the chemicals and how application by pigging enhances the performance of the total system. 223 Please purchase PDF Split-Merge on www.verypdf.com to remove this watern Pipeline Pigging Technology PARAFFIN TREATMENT Paraffin treating .
