3.4 Procesamientos semánticos: inferencias y comprensión.
B. El "texto base”
The societal impacts and key figures regarding the Substructure Disposal Alternatives are summarised below:
II Jackets/Tank: Summary of Societal Impacts
IIA IIB IIC IID IIE
Issues Reefs in-place Reef around Jackets to shore for Jackets to shore for Jackets/Tank to
Tank recycling. Tank left recycling, Tank shore for demo- in-place deposited in deep sea lition and recycl.
Impacts on
Small negative Small positive Small positive Moderate positive Moderate positive
Fisheries
Impacts on Small negative Small positive Small positive Large positive Large positive
free passage Personell 0.08 0.13 0.16 0.27 0.29 Safety (PLL) Costs 0.7 2.0 3.2 5.8 6.5 (bill. kroner) Norw. content 0.1 (15–19) 0.4 (19–21) 0.6–0.7 (20–23) 2.5–2.6 (43–44) 2.4–3.4 (36–52) (bill. kr. and %) Impacts on 190 640 900–1000 3,400–3,500 3,700–4,700 free passage
Fisheries
The Ekofisk Area has been described by the Institute of Marine Research as not being very important for Norwegian or international fisheries (Valdemarsen, 1994; Soldal et al. 1998). Still, some fishing takes place in the area, mainly from boats with trawl or purse seine gear.
An assessment of the impacts on fisheries for the Ekofisk I substructure Disposal Alternatives is complex. In relation to majority of the existing fishing activities in the area (trawling and seining), the Alternatives involving the removal of potential obstacles will be positive. The magnitude of this benefit is difficult to estimate, however. On the other hand, establishing artificial reefs should mean some level of positive impact for another branch of the fishing industry – that using passive instruments, mainly nets. Just how large this positive effect would be is also very difficult to estimate. Therefore the Institute of Marine Research has performed studies to quantify these effects, but concluded that there are still many unanswered questions and unresolved issues. This Imapct Assessment has chosen to follow the approach that most weight should be given to the pre-existing industry (trawl and seine), and thus the benefits that accrue due to removal of obstacles to trawls and seines, rather than the benefits that might accrue from reef effects.
Based on this the following impacts have been identified on fisheries for the various substructure Alternatives:
A number of reefs spread in different locations would present obstacles to existing fisheries (trawl and seine) over a wide area. A positive reef effect of this constellation of small reefs is found to be small compared to the nuisance to trawling. One reef collectively around the Ekofisk Tank will mean far fewer obstacles to fishing and thus a smaller negative impact than the «reefs-in- situ» option. By comparison with the present situation the collective reef option means freeing up a considerable acreage. The reef effect (added fish stock production value) is uncertain, but assessed as positive.
Alternative IIC, involving removal of steel jackets and leaving the Ekofisk Tank where it stands, will mean that only a single obstacle remains, and the positive effects of removing the others result in a «small positive» rating.14
Full removal of jackets and Ekofisk Tank at Ekofisk I (as in Alternatives IID and IIE) will mean removal of all obstacles to fishing and thus a «moderate positive» impact.
IIA IIB IIC IID IIE
Jackets and Tank Jackets and Tank Jackets to shore Jackets to shore Jackets/Base used as fish reefs used as fish reef for recycling, for recycling, to shore in-place around Tank Tank left in-place Tank deposited for recycling
in deep sea Area released 0 21–22 22.5 24 24 (km2) Number of areas with 8 1 1 0 0 obstacles
Reef effect 1–3 boats 1–3 boats None None None
(post 2028)
148
Free passage
The operational phases of the various Disposal Alternatives will all be of limited duration, and will not influence navigation to such a degree that measurable effects would ensue.
In relation to today’s situation, most of the substructure Disposal Alternatives can be considered positive from a passage point of view. It could be argued that the «reef in-place» Alternative (IIA) would have a «small positive» impact, since the jackets will generally have sufficient sailing clearance. Some of the jackets, however, could intrude into the 55 metre surface zone that the IMO Guidelines advise as the safety clearance for large surface vessels in storm conditions, and all sunken objects will represent a potential threat to submarines. Another difference compared with today’s situation is that the field standby boats will no longer be on station at the outlying fields, and even if adequately marked, these reefs would represent a potential risk to maritime activities. The reefs in-place option is therefore given a «small negative» rating.
Leaving the Ekofisk Tank in-place is rated as having a «small negative» impact, comparable to today’s situation. Altogether, Alternative IIC is assessed as having a «small positive» impact, since all the jackets will be removed and only a limited obstacle will remain. A similar rating is given to the «reef around Tank» option (Alternative IIB), since any obstacles to shipping are concentrated in one place. If the result is compared with the original undeveloped field and not with today’s situation, the consequence of a cluster reef is assessed as a «small negative» impact.
Removal of all the substructures (Alternatives IID, IIE) results in a «large positive» impact in relation to the free passage of shipping.
Personnel safety
The safety of the personnel engaged in the removal work is of vital concern. Therefore calculations have been made of representative parameters for personal safety to assess the level of risk. The results are presented as Potential Loss of Life (PLL) below.
If we only consider the risk contributions from the jackets and Ekofisk Tank, then Alternative IIE has the highest risk to life (see Figure 49).
0.3 0.25 0.2 0.15 0.1 0.05 0 Alternative A ■ Tank ■ Jackets Figure 49
Personal risk comprised of contributions from Jacket and Tank alternatives
Alternative B Alternative C Alternative D Alternative E PLL
The increase in PLL for Alternatives IID and IIE is solely due to the removal of the Tank. Section 7.4.3 below, presents the PLL effect of the Tank substructure removal in isolation, and in combination with the Tank topsides.
Norwegian content and employment effects
The maximum Norwegian content is 3.4 billion kroner for the most expensive solution if all demolition and recycling is awarded to Norwegian contractors. The Norwegian content of the most inexpensive Alternative, if demolition and recycling is performed abroad, can be as low as 0.1 billion kroner.
If all substructures and the Ekofisk Tank are removed the total production effects will reach 4,000–5,000 man-years provided demolition and recycling take place in Norway. The least costly Alternative if demolition and recycling are done abroad will result in about 190 man-years in production effects in Norway.