Posts in Case Study
Remaining Life Assessment of Subsea Jumpers, Flowlines & Risers

GATE was engaged to evaluate the current condition and remaining life of the subsea jumpers and flowline of a deepwater oil and gas facility in the Gulf of Mexico.

The subsea field, which was comprised of multiple oil wells, was produced at a Tension Leg Platform (TLP) with a nominal capacity to produce 100,000 barrels of oil and 50 million cubic feet of gas per day. The subsea and topsides facilities were designed to operate with an expected maximum carbon dioxide (CO2) concentration of 0.15 mole percent from any given producing well.

Read More
Post-ILI Corrosion Assessment & Wax Control Strategy

After an in-line inspection of a pipeline in West Africa, a client discovered significant wall loss in the first three miles of the line. The tool also returned significant wax deposits, casting doubt on the current wax management efforts in place.

The wells producing to the pipeline historically produced H2S; however, the worst offenders were shut-in quickly after it was discovered that they were producing extremely high concentrations of the sour gas.

Read More
Third Party Facilities Assessment

As part of a recent asset acquisition due diligence, GATE was asked to deliver a third party review of the condition of the asset and remaining production life of a floating production system and a fixed jacket.

GATE developed a standardized work process to evaluate the current condition, potential production bottlenecks and future operating expenditure (OPEX) associated with the brown-field producing asset.

Read More
Inspection of Mill Certificates

During the fabrication of the subsea boarding valve skid for a major offshore platform in the Gulf of Mexico, the fabricator purchased several large forgings.  These large forgings, from 8” to 12” in diameter, were to be machined into block valve bodies rated to 15,000 psig. As part of the agreed-upon Inspection and Test Plan, the mill certificates for the forgings were reviewed by the fabricator and by the company inspector.

Read More
SlipLine® - Pipeline Remediation Solution in LA Wetlands

A Louisiana operator experienced integrity issues with an existing 3 inch saltwater disposal pipeline. Production history recorded multiple leaks in the existing pipe, which resulted in environmental remediation. Upon investigation the operator determined that the said discharge pipe was unsuitable for future use. BlueFin was sought to review the situation and develop a plan of action that would resolve the integrity issues.

Read More
Steam Plant Piping Corrosion

A steam generating plant supporting an associated thermal recovery project in the Middle East was experiencing through-wall corrosion of carbon steel lines. In some locations this was aggressive enough to corrode through replacement piping in as little as two months.
Downtime in the steam plant was reducing heavy oil production and increasing OPEX. GATE was invited to the site to take a closer look at the operation and management of the system and determine how corrosion could be more effectively controlled.

Read More
Onshore Asset Integrity Management

GATE was consulted to identify the source of unexpected levels of H2S that had been detected in the central processing facility. Ultimately, GATE was able to determine that multiple operational issues needed to be addressed to mitigate the high levels of H2S in the processing facility, rather than the H2S naturally occurring in the reservoir.

Read More
Life Extension Study

A large and complex offshore field in the Middle East was suffering from multiple leaks due to corrosion in the presence of high levels of CO2 and H2S in the production, seawater injection, aquifer water injection and produced water injection systems. This was resulting in excessive chemical injection expenditures and was impacting field revenues and uptime. The large, shallow water field consisted of several hundred wells and a complex hub and spoke infrastructure.

Read More
Inspection Plan Development for Mothballed Equipment

A South American operator developed plans to return a sulfur recovery unit to service after an initial ten years of service and a further ten years of mothballing due to changes in field production requirements.

The corrosive nature of molten sulfur, carbon dioxide and hydrogen sulfide in the unit, coupled with the expectation of a less than optimum preservation strategy in a littoral offshore environment, generated a large set of integrity risks that needed to be evaluated to determine the feasibility of repairing and reinstating the system for a further ten years of service.
 

Read More
Pipeline Evacuation & Assessment

A GoM operator witnessed a leaking 6” pipeline. Upon repairing the visual leak and attempting to perform a successful hydrostatic pressure test a second non-visual leak occurred, ultimately resulting in extended production loss.

In order to perform a second assessment and bring production back online, the pipeline assessment required a 100% fluidpacked volume of seawater to ensure an oxygen-free environment.

Read More
Hydrate Remediation

A Gulf of Mexico (GoM) operator in the process of decommissioning one of its fields requested the engineering assessment of a blockage existing in their flowline-riser. The reservoir fluid characteristics and the field’s operational history were extensively reviewed. The review indicated hydrates to be the likely cause of the blockage.

Read More
Paraffin Remediation

A GoM operator witnessed increased differential pipeline pressures on multiple production flowlines in a single field. Field history and maintenance projects indicated paraffin and asphaltene deposition. Routine measures to solve this particular flow assurance problem compromised conventional production chemical applications. While such chemical injection and batch solvent treatments provided resolution by retarding deposition, minimal mitigation resulted and no increase of production was achieved.

Read More
Pipeline Surveillance

As a result of paraffin deposition, a GoM operator experienced increased differential pressures in a bulk crude sales pipeline. Historical line maintenance followed normal production chemical treatment. Once pipeline differential pressures reached an alarming level, it was proven that conventional chemical treatment recommendations failed to protect the pipeline or mitigate the ongoing issue. In addition to increasing differential pipeline pressure, depositional shearing became a valid concern and threat to total pipeline plug off.

Read More
Hydrate & Wax Blockage Remediation

A West Africa field operator witnessed an abnormal increase in pressure topsides when the flowline circulation pump was used to pump dead oil into the production line. No increase in subsea pressure was observed. Operational history prior to blockage hinted at the possibility of the presence of one or both wax and hydrate blockages in the production line. Depressurization options were limited by the blocked gas lift line.

Read More