The FPS System has a Hydrogen Sulphide (“H2S”) safe operating limiting (“SOL”) of 10ppm/wt. The pipeline was designed for a different fluid composition than is currently transported. It is recognised that as reservoirs age, H2S levels are likely to increase and there is a risk for a breach of the pipeline H2S SOL which could pose an integrity threat to the FPS System. Higher H2S concentrations give rise to the potential for Sulphide Stress Corrosion Cracking (SSCC) - this failure mode is generally recognised to be instantaneous at highly stressed locations such as welds. BP’s H2S management strategy for the FPS System requires that H2S levels of all shippers are monitored to establish H2S levels and detect increasing trends, ensuring the integrity of the FPS System is maintained at all times. If a shipper believes that their H2S levels will exceed their TPA specification limit and/or the SOL of 10ppm/wt then they should contact BP immediately to agree an action plan. Under no circumstances should shippers export pipeline liquids into any spurline or FPS that exceed the SOL of 10ppm/wt. Failure to comply may result in BP shutting in the shipper’s production in order to protect the integrity of FPS.
Methanol has a significant impact on the six Kinneil molecular sieve beds that absorb water and H2S from the propane product stream, as methanol is absorbed by the beds in preference to water and H2S. This reduces the molecular sieve’s absorption capacity which leads to the production of off-specification propane. Once methanol has been absorbed by the bed it cannot be totally regenerated; this significantly reduces the molecular sieve bed’s lifespan which increases the frequency that the bed has to be changed out. The methanol capacity of FPS is around 2m3 per day. Methanol Partitioning Factors FPS has previously agreed a methanol partitioning factor with each shipper group operator. However, this partitioning factor could be affected by additional volumes of water being exported by the shipper at the same time. Please ensure that all relevant information is provided to FPS at the time the methanol waiver is applied for. Category 1 Methanol Waiver A Category 1 methanol waiver may be granted where FPS has adequate methanol capacity available to ensure that propane product remains within redelivery specifications; if capacity is not available then BP will reject the request. The shipper has the option to wait until capacity becomes available or request a Category 2 methanol waiver. Category 2 Methanol Waiver A Category 2 methanol waiver may be granted when FPS does not have adequate methanol capacity available to ensure that propane product remains within redelivery specifications, and granting of the waiver request would therefore result in flaring of propane product. The grant of a Category 2 methanol waiver is at BP’s sole discretion. BP is unlikely to grant a Category 2 methanol waiver if it is simply to avoid a couple of days delay in approving a Category 1 methanol waiver.
FPS has limited capacity for handling water; and has been receiving an increasing number of requests from shippers for excess water handling services, which have to be managed carefully within system limits. Produced Water Chemical Analysis Incompatible produced waters can present a significant risk to FPS operations, either through scaling or inefficient separation; however, access to representative water analyses from each field will allow BP to identify potentially incompatible fluids and manage waiver requests accordingly. To help BP process water waiver requests, FPS requests produced water chemical analysis information that reflects the water that is exported to FPS as BS&W.
Other Chemical Waivers
FPS has agreed with each shipper a list of production chemicals that can be used; these chemicals are routinely used in the operation of the field, such as corrosion inhibitor or solvents. If shippers wish to use ad-hoc chemicals or change any of the chemicals on their approved list then the shipper should complete a waiver request form and send it to the FPS waiver team. The approval process for other chemicals is likely to take longer than 72 hours as additional research and tests may be required before BP is able to approve the waiver; typically 2 months’ notice should be given to approve such a request. Any such request is subject to the waiver admin fee (see Waiver Fee section).