Updates to the emissions and discharge permit for Brage.

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1 Miljødirektoratet Mihaela Ersvik Postboks 5672 Sluppen 7485 Trondheim Your reference 2013/1216 Our reference BR00-LE-WIN-MD-0030 Our date Updates to the emissions and discharge permit for Brage. Wintershall would like to update the discharge and emission permit for Brage mainly in respect to the production chemical WT-1099 and hydraulic oils from submersed pumps. WT-1099 (red) Brage uses WT-1099 as a flocculant in the test separator in order to achieve better separation. The product works by attracting small oil droplets together making separation from water easier. Wintershall is in breach of the current permit due to the change in colour classification. Although Brage is allowed to discharge red classified chemicals, it was pointed out in an audit carried out by NEA that Brage does not formally have permission to discharge red chemicals for this particular use and hence the discharge permit must be updated. Wintershall is currently trying to optimize its oil-water separation process in view of the predicted increases in produced water. One of these optimizations was to look at the balance of emulsion breaker and flocculant as it was thought that these chemicals may not be optimal for the current water cut regime. MI-Schlumberger tested a range of their products in jar tests and found that some of their other products now out-performed the incumbent products. Wintershall will now field test some of these chemicals these include products in the green, yellow and red environmental categories. It is important to field test these in the actual separator with the actual water-cut regime, temperatures, flows and physical dynamics of the test separator. Unfortunately this work is taking much longer than anticipated and we had hoped to replace the red classified chemical. As this work will not be finished this year and in order to comply with the discharge permit and regulations Wintershall therefore applies for the use and discharge of Red chemicals from the oil-water process separator. For the 2015 discharge permit, we applied for use of 150 tonnes and a discharge of 58 tonnes for WT For the permit update, we would like to also take account of the following changes which makes the calculation for discharge more accurate: the reinjection regularity has improved with modification to the Statfjord water injection pump (2015), meaning that less than 1% of the EPCON (injected water) volume is diverted to sea because of operational disruptions: 2014 re-injection = 35,6% 2015 re-injection = 46,9% (modifications to Statfjord pump completed) 2016 re-injection = 52,5% 2017 re-injection so far = 51,8%

2 The dosing of WT-1099 is different for the EPCON reinjection line and the hydrocyclone/degasser line (normal discharge to sea line). The EPCON dose rate is approximately 200ml/hr whereas the degasser line is 100 ml/hr. The soluability/flocculating dynamics have not previously been considered in the NEMS Accounter calculation and the discharge has been overestimated. This is because the HOCNF states that 97% of the chemical will follow the water. But from discussions with the supplier, this is the case when no oil is present to flocculate. This is the basis that is previously used by Wintershall. But the HOCNF also states in the fate section that the product will follow the oil stream. So when oil is present, most of the WT-1099 chemical will follow the oil stream and not be discharged. Wintershall will use a conservative estimate of 6% for product that will not flocculate and follow the water stream to discharge (mainly to accommodate any possible overdosing). This has recently been borne out by analysis from a sample of the Brage sheen where the chemical flocculant could not be detected. This means that any discharge of WT-1099 is at very low levels. The total use of WT-1099 has decreased as the dose rate to the EPCON unit has been cut by 40% (during 2016). For WT-1099, we estimate currently that Brage is discharging approximately 10kg of red component to sea from the oil-water separation process per year. We are unsure with the testing of new products, including red classified products, what the total amount of discharge for red components will be. Another uncertainty comes in when the ECPON line has to be discharged, if and when this happens, more red component will be discharged than the estimated. Wintershall would like to apply for 100kg discharge of red component to cover these uncertainties. NC-5010 The enhanced oil recovery project where NC-5010 was injected was not regarded as successful. This reduces the use of the chemical in the yellow category by 90 tonnes (no discharges). PI-7192 / PI-7069 In the original application 2013 and revisions in 2015, it looks like these two chemicals were included with the full annual consumption for both chemicals instead of either or. Removing PI from the calculations reduces 250 tonnes of chemical. This explains the rather large overestimate for the use of red classified chemicals for production. Hydraulic oil from (caissons) In the letter of (your ref. 2013/10414 our ref. BR00-LE-WIN-MD-0026) we informed the NEA about the hydraulic oils in in the caissons. As these caissons have a depth of 40m for pump B and 70m for pumps A, C & D, we have previously considered these as closed systems. Several caissons have now been pulled and these contain most of the oil that is used, i.e. from leaking pumps, and confirming the closed-system. However, with wave movement, turbulences, eddies etc. These pumps will pump some of this leaked oil back to the surface. As there is a complicated topside system for this seawater distribution it is difficult to get a good estimate for this entrained oil. We have analysed a sample from the sea water return to sea and obtained a result of 14 µg/l (ppb). As a conservative estimate, with 100% pump capacity throughout the entire year amount to some 392 kg of hydraulic oil per year. This approximates at 20% of the annual consumption for the oils. We will need further sampling and analysis to establish a correct figure for reporting but, currently this calculation will give us a good indication for establishing a value for the discharge permit: Page 2 of 5

3 Use and discharge of hydraulic oils based for 2016 Total Total consumption discharge Distribution of environmental Consumption by environmental Discharge to sea by environmental Env. to sea category (%) category [tonnes] category [tonnes] Tradename Function Classifcation [tonnes] [tonn] Black Red Yellow Green Black Red Yellow Green Black Red Yellow Green Hydraway HVXA 46 Hydraulic oil Black 0,500 0, ,320 0,180 0,000 0,000 0,064 0,036 0,000 0,000 Renolin Unisyn CLP 46 NFR Hydraulic oil Black 1,500 0,300 90,8 9, ,362 0,138 0,000 0,000 0,272 0,028 0,000 0,000 total 2,000 0,400 1,682 0,318 0,000 0,000 0,336 0,064 0,000 0,000 The table above shows the approximate levels and based on 2016, but the the amount of hydraulic oil consumption varies from year to year. Wintershall, until more experience is gained would like to apply for to use of upto 2 tonnes in the Black category and 0,4 tonnes in the red category, together with a potential discharge of 400 kilos in the Black category and 75 kilos in the Red category, (F Hjelpekjemikalier reporting category). Clarifications API Modified Drilling and well operations We would like to clarify the use of API modified (classified as black). This was specifically applied for in the letter of for the application for use of API-Modified in connection with Well 31/4- A-06 A for the 7 ⅝ liner and high chrome steel threads. API modified needs to be used with the 7 ⅝ liner, whenever the liner is used. This has to do with the threading. The yellow alternatives have been tried and work when well when screwing in the liner, but, the problems arise with when the liner is unscrewed. The thread damage sustained is too great, so that the liner thread needs to be cut and the liner hanger re-threaded. This is both wasteful and costly compared to using API modified for this operation where there is no discharge to sea. For 2017, this liner operation was only planned for the 31/4-A-06 A well, but going forward we may need to use API-Modified, approximately 10 liters/ year resulting in a quota of 3kg /year for black classified components. So, no change to the applied amount, but that this is yearly, based on 1 operation/ year using this liner hanger equipment. Wintershall is looking at using different liner equipment and tubing connectors going forward for when the 7 ⅝ liner will need replacing. This may make the need for API-modified redundant going forward. Cuttings injection We would like to clarify that for the cuttings injection we add a viscosifier type chemical for slurrification of the cuttings so that they can be pumped into the re-injection well. These have been reported in category A - bore&brønnkjemikalier. EMI-2953 (green category) is commonly used and DuoTec NS (green category) have commonly been used, but Liqxan (yellow Y2) or Flowzan biopolymer (Yellow) may also be used with more problematical injections. The consumption depends on the lengths of the wells drilled but is in the range of 3 5 tonnes per year. These are chemicals that are commonly used for drilling as well and therefore there is no differentiation between the drilling use for the chemicals and the cuttings injection. If there is a need for differentiation, then these could be entered into the F- hjelpekjemikalier category? Page 3 of 5

4 Summarized We would like to update the discharge permit with the following changes - 1) Black classified components Tradename Function and use Consumption of Black components kg/year Hydraway HVXA 46 Renolin Unisyn CLP 46 NFR Hydraulic oil used in Hydraulic oil used in Discharge to sea of Black components kg/year So, no change in quantities for API-modified, but apply for a yearly use based on 1 operation per year using the 7 ⅝ liner hanger and high chromium connectors. 2) Red classified components Tradename Function and use Consumption of Red components tonnes/year Discharge to sea of Red components tonnes/year Hydraway HVXA 46 Hydraulic oil used in 0,200 0,045 Renolin Unisyn CLP Hydraulic oil used in 0,150 0, NFR WT-1099 Flocculant in oil-water 2,500 0,100 separators Reduction of PI-7069 Wax inhibitor for oil (no longer used) export Reduction in use of PI- Wax inhibitor for oil export Total -278,182 tonnes + 0,175 tonnes* * The total red quota for the discharge of red chemicals does not need to be changed from 11000kg. Most of this quota is for the use of biocide that kicks in when the sodium hypochlorite online production fails. In recent years this this has not happened very much! So, the main correction is that the quota covers the discharges from firefighting foam testing, biocide, tracers, hydraulic oils from the and the flocculant/demulsifier chemicals from the oil water separator process. 3) Yellow classified components No change at present. Wintershall would like to come back to this in 2018 as we estimate the discharge of yellow chemicals will be reduced in 2017/18, but may increase again during 2018/2019. We will update later in 2018 when the changes are better mapped with regard to the consequences of increasing water production through the Statfjord revitalisation project and the possible change out of the current flocculant and demulsifier. Page 4 of 5

5 Yours sincerely, Wintershall Norge AS Michael Lima-Charles Senior Environmental Advisor Copy to: Attachments: Page 5 of 5