MEG ARTS® confirms successful pipeline conditioning at two major subsea developments
Online Electronic’s MEG ARTS® has successfully completed a deployment on a large subsea development 60km off the coast of Ghana - it’s first in the sub region of West Africa. The system was employed to confirm successful chemical conditioning of a Gas Injection Pipeline in water depths of 1600m. It achieved this by analysing the density of Mono-Ethylene Glycol (MEG) being discharged from the pipeline during dewatering and capturing six samples for later analysis and confirmation.
Following the flooding and hydrotesting of the pipeline, a conditioning pig train consisting of four dewatering pigs each separated by a slug of MEG, was run from an FPSO to a subsea PLR. The MEG ARTS® system was deployed from a support vessel and connected by hose onto the subsea PLR. During dewatering operations, the MEG ARTS® unit displayed and logged the pressure, temperature and density of the received fluids. The display was monitored by an ROV and samples were taken by ROV switch when predetermined density levels were observed.
Upon completion of the dewatering activities, the system was brought back to the surface where the data was downloaded from the analyser and the samples were recovered. The logged data clearly showed the increase in MEG density upon receipt of each of the three slugs and confirmed that the customer target density of MEG purity had been exceeded. This confirmation was critical as due to operational issues, previously calculated theoretical data could not be relied upon. This demonstrates that MEGARTS can verify pipeline acceptance and is not only a means of verifying existing calculations. Subsequently, the operator was able to move swiftly onto the next stage of the operation without further analysis of the samples, resulting in time and ultimately cost savings.
MEG ARTS® was also utilised in the UKCS this summer, where a new 62km, 10” gas export pipeline system was successfully conditioned using Triethylene Glycol (TEG). Once deployed, the unit was left unattended without a vessel present to log data, which when recovered, confirmed the client target of TEG purity had been achieved. This highlights that by autonomously taking samples and logging the conditions of the fluid being received, a support vessel does not have to be stationed at the receipt site, resulting in significant vessel time and cost savings.