This paper discusses a reservoir conditions laboratory investigation into the fast track Easington Catchment Area (ECA) Neptune Development which was identified as requiring sand face completion design. During the front-end engineering design phase the initial case accepted for the platform and sub-sea processing facility was zero sand tolerance. Rock mechanical test results suggested that an open hole gravel pack was the best sand face completion option, however many formation damage mechanisms are known to be encountered during well operations.
The emphasis of the paper is to explain an investigation of the design phases of a sand face well completion under laboratory conditions. Therefore, each phase of laboratory testing looked at identifying and reducing formation damage mechanisms prior to well operations. To aid in interpreting permeability results and identifying damage mechanisms, dry and cryogenic Scanning Electron Microscopy (SEM) analyses were performed on samples before and after testing. This interpretation was used to determine whether formation damage occurs within the gravel pack assembly and interfaces or within the core. The advantages of well-designed drilling mud can be ruined by a poor completion procedure. Therefore, throughout the development phase it was strongly emphasized that synergy between the drilling phase and completion was paramount. An operational strategy was then generated from the results, which led to the installation of the sand face completions with minimal formation damage.
After implementing the preferred drilling mud, displacement of the drilling mud, then the associated enzyme and acid treatments post gravel pack operations from the core study, the Neptune Well showed extremely low skins. This production data confirms the importance of laboratory analysis undertaken on representative core intervals as a well performance predictive tool.