Deployment of Emulsified Scale – Inhibitor Squeeze to control Sulphate/Carbonate Scales within Subsea Facilities in the North Sea Basin

摘要

This paper presents laboratory/field results and lessons learnedfrom a North Sea field where a novel emulsified scaleinhibitor was deployed via bullhead squeeze treatments in fourlow water cut, sand screened wells. The field is a subseadevelopment within the UK sector of the North Sea. Thesewere the first squeeze treatments to be performed on the field.The remote location of the production wells relative to theproduction vessel and their high production levels meant thatscale management was critical to the effective recovery ofhydrocarbon from the field. The risk of scale formation evenat low water cut was deemed sufficiency high for a scaleinhibitor squeeze application to be applied.The decision to use emulsified scale inhibitor for treating suchlow water cut wells was arrived at after an extensive series oflaboratory tests including formation damage coreflood studiesand assessment of chemical retention. The risk of finesmobilisation when deploying water based chemicals in lowwater cut, poorly consolidated reservoir will be outlined.The challenges with the deployment of the chemical packagevia a diving support vessel (DSV) and gas lift line will also beoutlined along with the performance of the wells following thetreatment and the effectiveness of this scale control method.This paper will outline in detail the particular issues associatedwith chemical injection to a subsea facility, many of which arecurrently being developed in the Gulf of Mexico and is a good example of lessons learned and sharing best practice fromanother oil basin.