Increasing Production with an Innovative Through Flow Line (TFL) Multi-Zone Completion Design for a Major Norwegian Operator

摘要

Norsk Hydro operates the Snorre Field in the Norwegiansector of the North Sea with a tension leg platform (TLP) anda sub-sea production system. The initial sub-sea wells weredesigned with completions that would allow through-flow-lineservicing, and while the wells were functioning as designed,production had been declining. Therefore, Norsk Hydro feltthat the completion concepts should be evaluated for new fielddevelopments. The ensuing investigation and developmentproject led to a novel well completion concept, which is thefirst “intelligent well” subsea completion installation offshoreNorway.This innovative design changes retain the original through-flow-line (TFL) service technique system and subseainfrastructure without any modifications, maximize productionby introducing 7-in. tubing, and include hydraulically operatedinflow control devices.The supplier and operator developed the conceptduring the winter 1998/1999 and designed the resulting systemduring spring 1999.License approval for prototype development andqualification was given in the summer of 1999, and the systemcomponents were in-house tested at the supplier base in Dallasduring the fall of 1999. A thorough system qualification wasperformed at an independent Norwegian drilling and well testcenter during spring/summer of 2000. The qualificationincluded a full test-well installation and necessary interventionactivities to prove the functionality of the concept. The systemwas qualified during the summer of 2000. The first subseawell installation was done at Snorre and put on production inDecember 2000. The well completion consisted of a 4-zone/interval design for improved reservoir management.The concept principles also have application for other typewells on platforms where modifications to the wellhead andtree are not feasible.The development process and qualification of the systemhas been conducted in a very short time period from idea tooffshore implementation. This is mainly the result of a veryfocused personnel team with competent and dedicatedpersonnel between supplier, operator, and 3 rd party testingcontractor.This paper will discuss the improved system and testingthat resulted from this project. The first new productionsystem was installed in a side-tracked well, and the results ofthe completion will also be discussed.