Case Studies

The scope We secured a contract in 2015 with a major international operator to perform a study on a subsea main control umbilical (MCU), servicing two subsea control modules via a junction box under a floating production vessel (FPV). The study was undertaken after a recent remotely operated vehicle (ROV) survey of the MCU identified …

Optimising the efficiency of subsea installation maintenance Read More »

The problem Our client was planning on developing several marginal fields in the Dutch sector of the North Sea, expected to produce for approximately 5 years. Following on from Jee’s previous CAPEX and OPEX study for the new field development, Jee was asked to carry out a further flow assurance study. The purpose of the …

North Sea routing and flow assurance Read More »

The problem A crack was identified on a diagonal structural member of a platform jacket structure located in the northern North Sea during a 2015 subsea survey. Connected to this member are two major export risers; 24” oil export and 20” gas export. Following identification of the crack, the client performed an analysis of the …

Severed structural member analysis Read More »

The scope A major operator asked us to undertake a stability analysis of a 20″ trunkline to ensure the pipeline was stable. The as-built concrete coating thickness stated in the final survey report differed from the thickness given in the coating specification, therefore a re-assessment of stability was required. The solution The on-bottom stability analysis …

Assessment of pipeline on-bottom stability to DNV-RP-E305 and DNV-RP-F109 Read More »

The scope An international operator asked us to perform a detailed span assessment for a major pipeline system. The scope included updating existing span anomaly criteria to the latest DNV code, using the most recent environmental data available, and recommending the maximum allowable span lengths. The solution Our team conducted analyses to determine the: Maximum …

Assessment of pipeline free spans to DNV-RP-F105 Read More »

The problem During a routine inspection of one of their risers, our client noticed that some of their riser guides were oversized, resulting in clearance between the riser and the inside of the guide. The riser had an outer diameter of 10.75 inches. The internal diameter of the guide was 14 inches. The clearance between …

Riser analysis Read More »

The problem Our client had identified an area of internal corrosion inside a riser bend within the platform topsides. It was identified that a fully pressure-retaining welded steel sleeve repair was required to contain the corroded region, for which a bespoke design was required. The solution Jee first completed a definition phase to establish a …

Steel sleeve repair for riser bend Read More »