Re-Perforating Formerly Inaccessible Well Areas Beneath CompletionCollapse and Axially Displaced Tubulars

摘要

In several producing fields throughout the Norwegian continental shelf,operators are facing aging wellswith heavily deformed completions that are producing below their potential.In order to find a technicalsolution to improve production that can be operated through completion deformations,Archer,Archer haspursued a full technical study of existing collapse geometry,axial pipe displacement and reproduced themin full scale 3D models in order to test a newly engineered slim and highly flexible perforating systemdesigned to be conveyed by carbon composite rod with embedded electrical cable.In March 2018,work began in parallel on two linked projects.We needed first to understand thedifferent profiles and geometries of an inaccessible deformed tubular,in order to reproduce and modelthe axial displacement on scale.In parallel with the deformation modelling,we needed to engineer withour perforating system manufacturer an interchangeable and flexible perforating system capable of passingthrough the 3D model deformations.A complete study of downhole recorded well data from deformed areas was performed to catalogue thedifferent possible shapes and internal diameter reduction of tubing and liner under axial compression.A 3Dmodelled transparent plastic tubular system has been engineered in order to reproduce the exact downholedimensions and conditions of known deformed areas.The modelled deformations needed to be robust andlong enough to support real downhole tools and fully transparent so we could understand the differenttoolstring's behaviorsbehaviours depending on the Bottom Hole Assembly(BHA)set up and shape of thedeformation.The deformation testing system has been created as a light weight interchangeable tubularsystem designed to interlock quickly and easily in various combinations.In the meantime in the parallel twin project,the initial task was to review the current product portfolioof slim through tubing equipment.The completion with heavy wall liners,intended to minimize thedeformation caused by reservoir formation movements,challenged the charges selection that could be fittedinto slim perforation systems.Due to the minimum hole size requirement,the gun system was also designedto self-orient to the low side of the casing.The drafting team analyzedanalysed the internal gun systemand added a weighted row to assist with gun orientation.The final system to be tested in the modelleddeformation is composed of interchangeable swivels,knuckle joints,rollers,and single or multiple shotslim and short guns incorporated with addressable switches.Over 30 different well deformation shapes have been recreated in order to test and select the bestperforming flexible perforating system combination,leading to more than 200 documented results.Theflexibility and reduced Outer Diameter(OD)of both downhole system and composite carbon rod allows topass successfully through several heavily deformed tubulars,when every other conventional rigid systemhave has failed.