Barents Sea South-East

02.07.2013

After the treaty with Russia on maritime delimitation and collaboration in the Barents Sea and the Arctic Ocean came into force on 7 July 2011, work began on a process to open Barents Sea South-East for petroleum activities.

The sea area covered by this process embraces some 44 000 square kilometres. It extends north to 74°30’N, is bounded by the Russian sector to the east, and is delineated in the west by the opened area of Barents Sea South. See the map in figure 6.1. This area is almost as large as Finnmark county.

 

The Barents Sea South-East area and the most important section of the sedimentary succession in this area from a petroleum perspective.


Figure 6.1
The Barents Sea South-East area and the most important section of the sedimentary succession in this area from a petroleum perspective.

 

An opening process is intended to provide the technical facts on which the Storting can base a decision. As part of this work, the NPD has mapped the geology of the area and estimated its resource potential. The principal results of this mapping were published in February 2013 and are presented in White Paper 36 (2012-2013) concerning new opportunities for northern Norway – opening Barents Sea South-East for petroleum activities.

This chapter provides a more detailed technical review of the geology and the results of the geological mapping than has been published earlier. It also presents the NPD’s estimate of undiscovered resources in the area.

 

Data

Geological knowledge of Barents Sea South-East is relatively limited. No shallow scientific or exploration drilling has so far taken place there. On the other hand, a number of wells have been drilled in the open part of Barents Sea South. Some published data are also available from commercial drilling in the Russian sector of the Barents Sea. Wells in other parts of the Barents Sea provide relevant information (well logs, dating, core measurements and calibration of seismic data) which is crucial for understanding the petroleum system and reservoir properties in Barents Sea South- East.

Two-dimensional seismic data was acquired by the NPD during 1974-82 in the boundary area with the Russian sector where the two countries had overlapping interests. The quality of these data is very variable, and the data coverage low and unsystematic. No seismic surveys were conducted by the Norwegian authorities from 1982 until the maritime delimitation treaty between Norway and Russia came into force.

The new seismic data package comprises two 2D seismic datasets acquired during the summer seasons of 2011 (about 11 500 kilometres) and 2012 (about 6 800 kilometres), as shown in figure 6.2.

 

2D seismic data acquired in 2011 (red) and 2012 (black) in the Barents Sea.

Figure 6.2 2D seismic data acquired in 2011 (red) and 2012 (black) in the Barents Sea.

 

GeoStreamer technology was used in the 2011 survey. This means that the hydrophone streamer is towed at a greater depth in the water than with conventional seismic surveys. The operation can thereby cope with higher waves, is less weather-dependent and consequently more efficient. Conventional 2D methods were used in 2012.

Emphasis was given during the 2011 and 2012 surveys to systematic acquisition with long lines covering the whole of the new area up to 74°30’N. A grid measuring roughly 5x20 kilometres was established in 2011 in order to obtain an overview of geology in an unknown area. Supplementary seismic data were acquired in 2012, with particular emphasis on the most interesting areas.

Gravimetric and magnetometric data were acquired alongside the seismic surveys in 2011 and 2012. This information could help to improve understanding of the deeper structuring.

Processing all the seismic data acquired in 2012 was completed during November/early December of that year. Relatively shallow waters, a hard seabed and a very marked reflector from the Lower Cretaceous made processing a demanding business, but the NPD considers the quality of both raw data and processing to be satisfactory.

 

Main structural features of the area

Five large regional geological elements define the structural picture in Barents Sea South-East. See figure 6.3. At the southern end of the area, the Finnmark Platform abuts the Norwegian coast with strata generally dipping northwards. In the north, the eastern section of the Bjarmeland Platform extends into the new areas. Strata here generally dip southwards. Between the two platforms, the Nordkapp Basin has developed as a deep Carboniferous/Permian subsidence basin where large quantities of salt have been deposited. The Tiddlybanken Basin forms a corresponding salt basin to the south-east. Both basins have been subject to intensive salt movement through the Triassic and up into the Palaeogene. The fifth large structural element in the region is the Fedynsky High, most of which lies in the Russian sector.

 

Timeline map from the base of the Cretaceous showing the most important structural elements in the geology of Barents Sea South-East.

Figure 6.3 Timeline map from the base of the Cretaceous showing the most important structural elements in the geology of Barents Sea South-East.

 

Finnmark Platform

The Finnmark Platform covers a large area extending from west Finnmark along the Varanger Peninsula and into the Russian sector. From the seismic data, Lower Carboniferous deposits appear to lie directly on the basement in many parts of the new areas on the Finnmark Platform. Little basis exists at present for saying that Devonian basins have developed under the Carboniferous sediments in the new areas on the Finnmark Platform. But the presence of some small sedimentary basins older than the Carboniferous cannot be excluded.

The Finnmark Platform is perhaps best known for its shallow marine limestones and dolomites with reef structures in the shape of carbonate and sponge (spiculite) reefs. These limestones formed in the Carboniferous and Permian. Towards the end of the Permian, the carbonate rocks were covered by the sea. This event forms a good seismic reflector which can be followed over long distances. During a brief period, the sea over the Finnmark Platform deepened before the development of a large delta began to fill the whole Barents Sea. That started at the boundary between the Permian and the Triassic. Close to the coast in the new areas, the traces of this deposition are clearly visible in the seismic images as clinoforms from the Lower Triassic, as shown in figure 6.4.

A large structure has developed at the boundary between the northern Finnmark Platform and the Tiddlybanken Basin. See figure 6.3. This structure has a small pillow of salt or anhydrite at its core. The Triassic and Jurassic sedimentary successions in this structure have not been eroded during the Palaeogene or Quaternary, so that the most important reservoir rocks are assumed to be intact there.

 

Seismic line showing the development of a delta (clinoforms) in the Lower Triassic. The line is flattened atop a Permian limestone reflector. Its position is shown in the inset map.

Figure 6.4 Seismic line showing the development of a delta (clinoforms) in the Lower Triassic. The line is flattened atop a Permian limestone reflector. Its position is shown in the inset map.

 

Nordkapp and Tiddlybanken Basins

The Nordkapp and Tiddlybanken Basins are two marked subsidence basins located north-west and north-east respectively of the Finnmark Platform. Their axes run at an angle of almost 90 degrees to each other. The characteristic feature of both basins is the formation of large quantities of salt during the Carboniferous and Permian. This salt initially lay largely undisturbed after its deposition. As delta development during the Lower Triassic reached the respective basins, the load on the salt deposits became so high that the salt began to move upwards through the sedimentary succession because its specific gravity was lower than the surrounding sediments in the basin. See figure 6.5. These salt movements occurred in several rounds during the Triassic and Palaeogene. As a result, the salt today forms large, almost vertical salt diapirs.

 

Seismic line through the Nordkapp Basin showing the development of salt diapirs and rim synclines in the Triassic. Its position is shown on the inset map.

Figure 6.5 Seismic line through the Nordkapp Basin showing the development of salt diapirs and rim synclines in the Triassic. Its position is shown on the inset map.

 

Most of these extend up to the seabed. Rim synclines formed in W E the areas around the salt structures with thicker layers of Triassic sediments and heavy erosion from time to time of the strata closest to the salt structures. A very large salt diapir has formed in the Tiddlybanken Basin on the Norwegian side of the boundary, with a well-developed rim syncline around the salt plug, as shown in figure 6.3. A seismic line along the salt diapir suggest that it has two domes. The bulk of the sediment in the rim synclines derives from the river systems and delta development in the east and south-east, which flowed around the salt structures.

A large salt structure has developed in the north-easternmost part of the Nordkapp Basin (see figure 6.3), where the base-Cretaceous reflector is eroded but where sediments in the Lower and Middle Triassic have been preserved. This structure could have a potential to contain oil or gas in the Middle Triassic.

With many of the salt structures, the seabed is higher than the areas surrounding the structures and forms a positive relief. This is clear over the Tiddlybanken Basin and several of the structures in the Nordkapp Basin. Seismic data show that the salt could have drawn limestones with it up to the seabed, which have laid themselves over the salt structure, and that erosion during the Quaternary removed the softer surrounding sediments. This could have prevented the salt from flowing out into the sea. An alternative is that the salt remains active, and forms a structural relief as it rises towards the seabed. The relief could be a combination of these two models.

 

Bjarmeland Platform

The Bjarmeland Platform covers large parts of the central Barents Sea. It is characterised by relatively few structures, but certain large ones could be important as oil and gas traps. In many cases, a pillow of salt at the base of these large structures controls structuring in the Palaeogene. A good example of such large structures is the Norvarg Dome, where gas has been found in several intervals from the Triassic to the Jurassic.

The Bjarmeland Platform extends into the northern part of Barents Sea South-East, where a large structure has developed which appears from the seismic images to have retained a more or less intact sedimentary succession from the Permian to the Upper Jurassic. See figure 6.6. This structure rests on a pillow of CarboniferousCarboniferous/ Permian salt. A series of small Palaeogene faults have developed in the structure, which affect the structures at Triassic, Jurassic and Cretaceous levels. A number of these faults extend right up to the seabed. Seismic amplitude anomalies on some of these faults indicate that gas is probably leaking from gas reservoirs in the Realgrunnen sub-group. See figure 6.7.

 

Large structure in the northern part of Barents Sea South-East. The position is shown on the inset map.

Figure 6.6 Large structure in the northern part of Barents Sea South-East. The position is shown on the inset map.

 

Gas leakage from a bright spot in the Upper Jurassic (section of figure 6.6).

Figure 6.7 Gas leakage from a bright spot in the Upper Jurassic
(section of figure 6.6).

 

Fedynsky High

The flank of the Fedynsky High lies in the eastern part of the new areas, with its bulk on the Russian side. New seismic data show that it has a complex geological history. A deep graben cuts into the Carboniferous/Permian on the Norwegian side. This basin is later inverted, and currently forms the highest point of the Fedynsky High in the Norwegian sector. See figure 6.8. The continuation into the Russian sector is unknown because access to data is lacking. The basement probably stands high up on both sides of this basin and gives rise to gravitational and magnetic anomalies on the Fedynsky High. Running in the same direction as the Tiddlybanken Basin, the basin extends west to the Nordkapp Basin. Mappable quantities of salt have developed in this basin, but not sufficient to form salt diapirs.

It is already known that the top of the Fedynsky High has been heavily eroded in the Russian sector. The new seismic data confirm that virtually the whole sedimentary package above the base of the Cretaceous has been eroded away on the Norwegian side. Old published maps from the Russian sector show that the erosion descends deep into the Triassic there.

 

Seismic line from the flank of the Fedynsky High, which shows that a Carboniferous/Permian graben structure with salt deposits underlies its highest part on the Norwegian side. The position is shown in the inset map.

Figure 6.8 Seismic line from the flank of the Fedynsky High, which shows that a Carboniferous/Permian graben structure with salt deposits underlies its highest part on the Norwegian side. The position is shown in the inset map.

 

Reservoir rocks

Several important factors govern the formation of reservoir rocks in Barents Sea South-East. The original deposition environment is important for reservoir properties and, because the area is large and stretches a long way, this will vary between the different areas at one and the same time. When fluvial sediments with channel sandstones were forming in the south, more continuous shallow marine sandstones may have developed to the north. Limestones and sponge reefs have formed in other epochs, and could have given rise to reservoir rocks.

The common denominator of all the reservoirs is that burial depth is an important factor governing their properties over time. At shallow depths, the reservoirs will have good properties, as in well 7131/4-1 (Guovca) on the Finnmark Platform. If the reservoir is buried too deep, porosity and permeability – and thereby flow properties for oil and gas – will eventually deteriorate. Ultimately, these properties will be so reduced that the rock can no longer be regarded as suitable for a reservoir.

Rocks in the new areas have been uplifted by 1 000-1 500 metres. When estimating reservoir properties, changes will be governed particularly over time by the maximum depth of burial and temperature. Middle and Upper Triassic and Jurassic reservoirs in the relevant areas will lie at an acceptable depth, where it is reasonable to assume that their properties have been preserved. At deeper Lower Triassic and Carboniferous/Permian levels, reservoir properties may primarily have been preserved in areas close to the coast where these rocks have not been buried too deeply. In some formations, a secondary growth of chlorite has occurred which may prevent quartz overgrowth in the rock pores and preserve relatively good porosity down to greater-than-normal depths.

One of the biggest challenges in the central parts of the Barents Sea is the sealing potential. That applies particularly to possible Jurassic reservoirs. Uplift in the Barents Sea and the accumulation N Fedynsky High S Base Cretaceous unconformity Ladinian Induan Intra Induan Top Permian Early Carboniferous Basement Basement Graben Salt Figure 6.8 Seismic line from the flank of the Fedynsky High, which shows that a Carboniferous/Permian graben structure with salt deposits underlies its highest part on the Norwegian side. The position is shown in the inset map. of salt in the cores of most structures have caused intense fracturing and the development of small faults in and above the structures. These extend in many places right up to the surface or halt at unconsolidated Quaternary deposits. Seismic data indicate that gas is leaking from the Jurassic reservoirs in some structures. This shows that gas has formed in the area. The question is how much gas remains in the reservoirs and whether oil can be found.

Maps from the Mareano project mapping the bed of Barents Sea South-East, which are available on Mareano’s website at www. mareano.no, show the presence of a great many pockmarks across large parts of the area already mapped. Such pockmarks are formed in unconsolidated seabed sediments by the expulsion of water or escape of gas. Their regular distribution over large areas may indicate that they are caused by water expulsion or the escape of biogenic gas. Should the leakage relate to the escape of gas from older reservoir rocks, this observation could reduce the gas potential in the southern part of Barents Sea South-East.

 

Carboniferous/Permian

Carboniferous/Permian rocks lie too deep or have been too deeply buried across most of the new areas to be relevant as reservoir rocks. The exception is a small area close to the Norwegian coast, where these rocks extend right up to the seabed. Gas accumulations could be possible here in Lower Carboniferous sandstones. Possible traps will be stratigraphic or structural, but few faults exist to serve as traps close to the Norwegian coast. Possible Carboniferous and Permian prospects could exist in limestone and sponge reefs. The 2D seismic data are not sufficient to map this type of reservoir with any degree of detail. The area is limited in size, with the reef structures between one and 1.5 kilometres wide and their longitudinal extent unknown. Experience from wells 7228/7-1 A in the Nordkapp Basin and 7128/4-1 on the Finnmark Platform further to the west show that both oil and gas could be present in possible prospects, but the quantity is uncertain.

 

Lower Triassic

Seismic data show that the continental shelf has been extended in the Lower Triassic from east and south-east to west and northwest. During this process, shallow marine sediments could well have been deposited to provide the basis for sandstone formation. These are generally deeply buried, so that reservoir properties will be reduced across large areas. The number of structural traps is limited, but Lower Triassic reservoirs are the most relevant in the southern part of the new areas in particular.

 

Middle and Upper Triassic

Middle and Upper Triassic reservoirs have the biggest potential for containing oil or gas in Barents Sea South-East. Generally speaking, these possible reservoirs lie at a depth where their properties remain intact. At the same time, the retention potential is greater than higher up in the Jurassic, where gas is leaking from the structures.

The seismic data show that large parts of the sedimentary succession in the Middle and Upper Triassic appear to comprise delta plain deposition with channels which have flooded over the fluvial plain. The seismic signals are more continuous in the northern part. This might suggest that opportunities for finding continuous Middle Triassic marine sandstones are greater in this area. Both marine shales and shallow marine tidal deposits have been proven in shallow scientific boreholes on the Sentralbanken High. This increases the likelihood that marine sandstones also exist in the northern part of Barents Sea South-East. Small faults help to break up the reservoirs.

Upper Triassic channel sandstones with very good reservoir properties have been proven in well 7131/4-1 on the Finnmark Platform. This was drilled in a stratigraphic trap which proved to be dry. Where a source in the Tiddlybanken Basin is concerned, the well has been drilled in the shadow of the large structure separating this basin from the Finnmark Platform. That structure may have captured all the petroleum which could have migrated from the Tiddlybanken Basin.

The probability of finding gas in the Middle and Upper Jurassic is highest in the north, while gas and oil are more likely close to the salt basins in the south.

 

Middle Jurassic

Knowledge acquired from wells in the Barents Sea farther to the west shows that Middle Jurassic reservoir sandstones with good properties could be present in the new areas. Seismic amplitude anomalies suggest that gas pockets have been preserved in a number of the structures, but the seismic data also show that these reservoirs are leaking gas because of heavy fracturing caused by salt tectonics and a tight network of small faults. The retention potential in the Middle Jurassic is accordingly regarded as limited. The uplift history, with gas expansion when the pressure reduces, means that gas is expected to be the most probable hydrocarbon phase for possible reservoirs. A shallow reservoir depth with low gas density in the reservoirs indicates that the volume in the Jurassic prospects will be limited.

 

Source rocks

One of the biggest geological challenges in the new areas in Barents Sea South-East is the presence of source rocks which may have formed oil and gas in sufficient quantities to fill the structures mapped. The challenge for gas is relatively simple, since coal horizons and organic material are assumed to be present in both Lower Carboniferous rocks and large parts of the Triassic. In addition, organically rich dark shales and limestones in the Carboniferous and Lower Triassic could be relevant contributors to gas. A number of large and small gas discoveries in the Russian sector indicate that gas is present in the area. On the Norwegian side, the Norvarg Dome represents the most relevant analogue trap type in the platform areas. This is also a gas discovery. The biggest risk for the presence of gas in the new areas is retention in the structures because of Quaternary uplift. The source potential for gas must be characterised as satisfactory.

The source-rock challenge is greater for oil. Seismic data for the new areas show that the traditional source rock in the Upper Jurassic, which has formed an estimated 98 per cent of all known petroleum on the NCS, is not buried deeply enough to have given rise to oil or gas. There are few places where this source rock lies deeper than 1 200-1 200 metres today. Even though these rocks have been more deeply buried (1 000-1 500 metres) for a time, that would have been insufficient to initiate oil formation. This immaturity is documented in shallow drilling on the Sentralbanken High, where the organic content is high and has a composition favourable for oil formation but where the temperature has been too low. Finding other source rocks which could have formed oil will accordingly be necessary.

In and around the Nordkapp Basin, a small oil discovery has earlier been made in well 7228/7-1 A. A similar find was made on the Finnmark Platform with well 7128/4-1. The source rock for these two discoveries probably hails from the Lower Triassic or older. This source rock has accordingly been indirectly proven by discoveries, but not confirmed by drilling. The great uncertainty related to this source rock is whether it has sufficient volume to generate oil in commercial quantities.

The discovery on the Finnmark Platform lies in Permian sediments. This oil almost certainly derives from a Carboniferous source rock. Carboniferous limestones and dark shales have the potential to form oil and gas. This type of rock outcrops at Billefjord in Svalbard. Traces of oil in the Pyramiden mines and vaporisation of volatile petroleum further up the fjord show that Carboniferous source rocks have a potential to form petroleum. The probability that this has happened further south in the Barents Sea is relatively high. However, the volumes of oil which may have formed are very uncertain. This uncertainty relates both to the quantity of available source rock and how deep it is buried. If the source rock has been too deeply buried, it will cease to form oil. In such circumstances, the source rock is more likely to have formed gas.

Seismic data from the eastern areas show that a large delta or continental shelf edge has formed in the Lower Triassic and extended in a north-westerly direction from land. Ahead of this delta, the strata thin out and reveal a condensed sedimentary package which probably comprises black marine shales with an unknown content of organic material. This shale formed before the salt movements in the basins and is unaffected by disruptive folding, erosion and rapid sedimentation around the salt diapirs. The assumed shale in the Lower Triassic could potentially be a source rock for oil and gas, providing it has an organic content with the right composition. Wells which could confirm that hypothesis have not been drilled in this area. Should the shale in the Lower Triassic have the right properties, it has been buried at a favourable depth for oil to form. The temperature decline in the rock related to the Quaternary uplift of the Barents Sea has probably halted the process of forming possible additional oil. As a result, the relevant oil in the prospects would have formed prior to the uplift process. Great uncertainty prevails about this source rock. Were it to be proven, however, it could be the most important contributor to possible oil discoveries in Barents Sea South-East.

In the northern and western parts of the Barents Sea, mature source rocks have developed in Middle Triassic marine shales. Seismic interpretation of the new areas in the southern-eastern Barents Sea shows that delta and delta plain deposits are more dominant, and it is less likely that marine shales have been deposited in this area during the Middle Triassic. Great structural activity has also occurred in the Nordkapp and Tiddlybanken Basins, with the formation of salt plugs. This has led to rapid sedimentation around the plugs, which has also been unfavourable for the formation of marine source rocks in the Middle Triassic.

The migration of petroleum from source to reservoir rocks in Barents Sea South-East is assumed to have been essentially vertical. Little opportunity for inward migration from the east is offered by the regional structural picture. The Fedynsky High serves as a barrier here. At the same time, erosion on the Fedynsky High is fairly deep, so that much of the petroleum from the Jurassic and Upper Triassic in this area has probably leaked out.

In the NPD’s view, the probability of oil formation is highest in areas close to the salt basins. The hydrocarbon phase around the salt plugs and on the edge of the deep salt basins is likely to be both oil and gas. On the Bjarmeland Platform, including a large dome in the north-east, the likelihood that the hydrocarbon phase will be gas is very high. Gas discoveries in both the Norvarg Dome and Shtokman support this assumption.

The probability of a source rock which has formed commercially interesting quantities of gas is good. However, it is very uncertain whether a source rock for oil exists in the area and whether a possible source rock has sufficient volume to be interesting in a petroleum context. The NPD basically regards Barents Sea South-East as a gas province, but is keeping open the option that oil could also have formed in the area. That applies particularly in and around the salt basins.

 

Resource evaluation

Methodology

Whether petroleum exists in an area is always uncertain. Calculating resources in plays takes account of this uncertainty by riskassessing the various parameters of significance for the presence and retention of petroleum. Plays are also defined with uncertainty distributions for different reservoir and liquid parameters.

Defining plays is a method for systematising and grouping the geological parameters which characterise the play and which distinguish it from other plays.

 

Results

The most important reservoir rocks in Barents Sea South-East are found in Triassic sandstones. Jurassic and Lower Carboniferous sandstones, as well as Carboniferous/Permian limestones and reef structures, could also be relevant as reservoir rocks. The NPD has defined and mapped a number of plays in sediments from the Carboniferous/Permian to the Jurassic in Barents Sea South-East, and has performed a stochastic resource calculation. The risk assessment is based on the presence and retention of petroleum and uncertainty assessments of the various petroleum geology parameters.

A number of plays which coincide with the various main structural elements in Barents Sea South-East have been defined by the NPD. These relate to the Early and Late Carboniferous on the Finnmark Platform, and to the Triassic in the northern part of that area. Various Triassic plays have been defined in the Tiddlybanken and Nordkapp Basins, while plays on the Bjarmeland Platform are both Jurassic and Triassic. Various Triassic plays are defined on the Fedynsky High. Carboniferous, Triassic and Jurassic plays have been defined in the other parts of Barents Sea South-East.

Expected recoverable resources for Barents Sea South-East are estimated to be about 300 million scm oe, with a downside (P95) of 55 million scm oe (95 per cent probability that the resources are equal to or greater than 55 million scm oe) and an upside (P05) of 565 million scm oe (five per cent probability that the resources are equal to or greater than 565 million scm oe). The probability and cumulative distributions of the recoverable resources are shown in figure 6.9. Since at least one play extends into the open part of the Barents Sea and has been proven there by a discovery, at least one of the plays in Barents Sea South-East is confirmed and will consequently yield finds.

Interdependencies are expected between several plays, partly with regard to the presence of effective source rocks. Should drilling of a well prove a source rock which functions, the probability that this source rock functions for more plays will be high. Interdependence in source rock applies in part to several plays with potentially large resource volumes. This emerges clearly as a bimodality in the resource distribution. See figure 6.9. The resource distribution has two resource estimates with a relatively high probability (bimodality). The higher of these shows the effect of proving a source rock in a play which increases the probability that this will also be proven in other interdependent plays with expected high resource estimates.

 

The distribution and cumulative probability distribution of total undiscovered recoverable resources in Barents Sea South-East based on the play method. The bimodal probability distribution reflects the fact that interdependencies have been incorporated between several plays.

Figure 6.9 The distribution and cumulative probability distribution of total undiscovered recoverable resources in Barents Sea South-East based on the play method. The bimodal probability distribution reflects the fact that interdependencies have been incorporated between several plays.

 

Figure 6.10 presents the cumulative distribution of the recoverable resources, where the contribution from the various plays emerges clearly. The plays on the Bjarmeland platform contribute most to the high resource estimates.

 

The cumulative distribution of total recoverable resources in Barents Sea South-East. The various plays are grouped by structural elements and other areas in the region.

Figure 6.10 The cumulative distribution of total recoverable resources in Barents Sea South-East. The various plays are grouped by structural elements and other areas in the region.

 

The expected recoverable resources break down into about 50 million scm of liquids and roughly 250 billion scm of gas. See figure 6.11. It is uncertain whether the area contains oil-forming source rocks, and whether a possible source rock has had sufficient volume to be interesting in a petroleum context. As a result, more gas than oil is expected in Barents Sea South-East. The Bjarmeland Platform and Fedynsky High are considered to be pure gas provinces, while the Nordkapp and Tiddlybanken Basins plus the Finnmark Platform are regarded as combined oil and gas provinces.

 

The cumulative distribution of recoverable oil and gas resources in Barents Sea South-East.

Figure 6.11 The cumulative distribution of recoverable oil and gas resources in Barents Sea South-East. 

 

Estimates for undiscovered resources in Barents Sea South-East are uncertain. The potential for finding oil and gas is high. Gas is expected to account for 85 per cent of the resources and oil for 15 per cent. Confirmation of plays through discoveries could offer a substantial resource upside.

Adding the undiscovered recoverable resources for Barents Sea South-East to the estimate for the Barents Sea of 31 December 2012 increases undiscovered recoverable resources for this part of the NCS by 31 per cent. See figure 6.12

Distribution of undiscovered recoverable liquid and gas volumes for the Barents Sea in the 2012 analysis and in 2013 with Barents Sea South-East (BSSE) included.

Figure 6.12 Distribution of undiscovered recoverable liquid and gas volumes for the Barents Sea in the 2012 analysis and in 2013 with Barents Sea South-East (BSSE) included.