Offshore Corrosion Control Program For Platforms, Pipeline And Production Equipment (1975)

ABSTRACT Exxon uses a four-part Corrosion Control Program, as an effective means of monitoring and controlling corrosion of 89 offshore platforms, 90 offshore pipelines, and 80 oil and gas wells in the Gulf of Mexico. The program consists of: Part I - Internal pipeline corrosion control; Part II - External Underwater platform and pipeline corrosion control; Part III - External corrosion control of production equipment, piping and platforms above mean Gulf level; and Part IV - Subsurface well equipment corrosion control. Exxon?s experience indicates that a comprehensive Corrosion Control Program can minimize corrosion damage to platforms, pipelines, and production equipment. Corrosion inspections of platforms, pipelines, and equipment provide data for evaluating the effectiveness of different mitigation techniques. 1. INTRODUCTION Corrosion of offshore platforms and production facilities is a major operating problem, both in terms' of cost of equipment repair or replacement, and in terms of potential pollution. Even though many corrosion control techniques are developed as a science, the effective application of these techniques is, in many cases, an art. Over the years, experience has shown that management commitment and emphasis on follow-up is a must to have a successful Corrosion Control Program. Corrosion monitoring and evaluation of control measures are essential. Exxon uses a four-part Corrosion Control Program that includes not only pipelines and platforms, but all production facilities. A computer data base system is used to schedule activities and to maintain historical data of completed activities. This paper gives Exxon's approach in conducting corrosion mitigation activities in its offshore Louisiana fields. Each part of the four-part program presents corrosion control techniques, criteria, and follow-up methods. Since many corrosion control systems are selected based on past operating experience, Exxon's experience to date will be presented. II. GENERAL DESCRIPTION AND OBJECTIVES Internal pipeline corrosion control is accomplished by scheduled pipeline pigging, and batch and continuous inhibitor treatments. Several corrosion monitoring techniques are used to evaulate the mitigation measures. Electromagnetic surveys have been performed on an experimental basis to determine the integrity and serviceability of pipelines. Surveillance is maintained through a computerized scheduler which schedules corrosion mitigation activities for engineering and field operating personnel. Cathodic protection systems (i. e., impressed current, hanging sacrificial anodes, and built-in sacrificial anodes) are used for underwater platform and pipeline corrosion protection. 'Underwater platform corrosion inspections are performed to evaluate the effectiveness of the different system types. Comprehensive ultrasonic and X-Ray inspections and detailed visual inspections are performed to determine production equipment and piping corrosion. Based on these inspections, equipment replacement and platform painting programs are developed. Subsurface well equipment corrosion is mitigated by scheduled inhibitor treatments. Treatment history plots (iron count graphs) are maintained for individual wells and provide surveillance tools to determine treatment effectiveness' and needed treatment modifications. The most important of the Corrosion Control Program's long-range objectives are to:Reduce corrosion repair and maintenance costs through computerized surveillance and follow-up on corrosion mitigation actions, andSelect materials and chemicals for corrosion