Criteria for Sizing Multiphase Flowlines for Erosive/Corrosive Service

API publishes recommended practices for various aspects of petroleum production to improve availability of proven engineering and operating practices. One of these practices, API RP 14E, provides recommended minimum requirements for designing and installing new piping systems on offshore production platforms. The recommended method in RP 14E for sizing gas/liquid flowlines is to limit operating velocity to the erosional velocity' limit. The limit is set to avoid excessive pipe-wall loss resulting from erosion/corrosion. The erosional velocity limit is determined from an empirical equation based on the two-phase mixture density. The debate regarding the erosional velocity criteria continues. Many investigators reviewed the velocity limits specified by RP 14E and concluded that the limits are too conservative. To investigate possible changes to the criteria, a project was initiated to review the existing erosional velocity limits to decide what changes would be appropriate. Based on a review of information on erosion/corrosion data from the literature and from field data, preliminary recommendations for modifying the erosional velocity criteria were made. Additional information is needed, however, to verify the preliminary recommendations. This paper presents the proposed modifications to the erosional velocity criteria and discusses experiments being conducted to provide additional data on the erosion/corrosion mechanismmore » in corrosive two-phase flow streams.« less