The FPS 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. 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.
INEOS’s H2S management strategy for the FPS System requires that H2S levels of all customers are monitored to establish H2S levels and detect increasing trends, ensuring the integrity of the FPS is maintained at all times.
If a customer believes that their H2S levels will exceed their TPA specification limit and/or the SOL of 10ppm/wt then they should contact INEOS immediately to agree an action plan. Under no circumstances should customers export pipeline liquids into any spurline or the FPS that exceed the SOL of 10ppm/wt.
Failure to comply may result in INEOS shutting in the customer's production in order to protect the integrity of the 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 the FPS is around 2m3 per day.
Methanol Partitioning Factors
FPS has previously agreed a methanol partitioning factor with each customer group operator. However, this partitioning factor could be affected by additional volumes of water being exported by the customer 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 INEOS will reject the request. The customer 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 INEOS’s sole discretion. INEOS 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 customers 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 INEOS to identify potentially incompatible fluids and manage waiver requests accordingly.
To help INEOS process water waiver requests, FPS requests produced water chemical analysis information that reflects the water that is exported to FPS as BS&W (Base Sediment & Water).
Other Chemical Waivers
FPS has agreed with each customer 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 customers wish to use ad-hoc chemicals or change any of the chemicals on their approved list then the customer 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 INEOS 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 Fees section).