Integrity Assessment and Redeployment of Existing Mobile Offshore Production Unit for a Marginal Field Development

摘要

Redeployment of existing idle or close to end of lease mobileproduction units can provide a viable option to address financial anddelivery time challenges for development of marginal field orrevitalisation of the end of life for production assets. The deploymentof an existing MOPU readily meets these requirements with apotentially faster upgrade, integrity assessment and modificationproject timetable as opposed to conventional new build Facility. It alsotypically will have a simpler installation procedure and minimalabandonment costs. There are examples of this type project beingdelivered from formal project kick off to production in less than a year.The challenges for this type of project are managing the technicalaspects of integrity assessment and modification of topside layout, fasttrack delivery of either new or refurbished long lead equipmentpackages and structural integrity and refurbishment of the existing unitto a site specific fixed structure under a specific class notation. Therequirements for the site specific structure are location dependent andmay include environmental and geotechnical conditions that theoriginal MODU structure and initial conversion to MOPU was notintended to operate in.This paper provides an overview of the challenges and discussesvarious aspects of a redeployment project represented risk to theintegrity of a facility and the required inspection and repair andverification requirements for assessment and maintaining the facilityintegrity. This paper also provides an overall view in using theinspection and site specific characteristic data forcalibrations/validations of the original design and then initialconversion to maintain the safety level as ALARP. Integrityassessment, application and cost benefits assessments of a deploymentproject of an existing MOPU is presented for a gas export projectmarginal field development.