Prof. Christopher A-L. Jackson 1 Dr. Mark G. Rowan 2 Prof. Atle Rotevatn 3 Prof. Katherine A. Giles 4

Transcription

1 NORSALT STRATIGRAPHY AND TECTONIC EVOLUTION OF A LAYERED EVAPORITE SEQUENCE IN THE SOUTHERN NORWEGIAN BARENTS SEA: IMPLICATIONS FOR PETROLEUM SYSTEMS DEVELOPMENT AND PROSPECTIVITY Prof. Christopher A-L. Jackson 1 Dr. Mark G. Rowan 2 Prof. Atle Rotevatn 3 Prof. Katherine A. Giles 4 1 Basins Research Group (BRG), Department of Earth Science and Engineering, Imperial College, Prince Consort Road, London, SW7 2BP, UK 2 Rowan Consulting, Inc., th St., Boulder, CO 80302, USA 3 Department of Earth Science, University of Bergen, Realfagbygget, Allègaten 41, 5020, Bergen, NORWAY 4 Dept. of Geological Sciences, Institute of Tectonic Studies, University of Texas at El Paso, 500 W. University Ave, El Paso, TX 79968, USA c.jackson@imperial.ac.uk MOTIVATION Salt influences the development and prospectivity of petroleum systems and plays a key role in many of the world s great petroleum provinces. For example, salt mobilisation can deform overburden rocks, resulting in the formation of structural and stratigraphic traps (Fig. 1). Furthermore, salt mobilisation controls basin physiography, sediment dispersal, accommodation, and, ultimately, the distribution of source, reservoir and seal rocks. Salt is crystalline and has a low permeability, thus it may act as a seal to underlying or adjacent reservoir rocks. Layered evaporite sequences (LES) may themselves represent reservoir intervals if they contain non-evaporitic (e.g. clastic, carbonate) rocks. The composition of salt-bearing sequences is also important because it controls bulk rheology and, therefore, the propensity of the unit to flow and form diapirs, pillows, sheets and canopies. Determining the composition and stratigraphic architecture of salt-bearing sedimentary sequences, and the distribution and style of salt-tectonics associated with their mobilisation, are thus key elements of petroleum systems analysis in salt-bearing sedimentary basins. Fig. 1. Salt-related structural and stratigraphic traps in sedimentary basins. Source: The Southern Norwegian Barents Sea (SNBS) contains several salt-bearing sedimentary basins (Fig. 2), including the Nordkapp (Gernigon et al., 2011), Hammerfest (Olaussen et al. 1984), Tromsø (Brekke & Riis 1987) and Sørvestsnaget Basins (Perez-Garcia et al. 2013), in addition to salt-bearing platform areas and structural highs such as the Loppa High and Bjarmeland Platform (Kristoffersen & Elverhøi 1978). Furthermore, the SNBS is estimated to contain substantial quantities of hydrocarbons, some of which are likely trapped in structures related to the presence and flow of Carboniferous-Permian salt (source: NPD). However, our understanding of the tectono-stratigraphic evolution of the SNBS, in particular the composition and tectonic evolution of Carboniferous-Permian salt, is poor for two reasons. First, over the last 20 years, very little has been published on the salt tectonics of the SNBS. Second, the eastern 1

2 part of the SNBS is part of the former disputed zone between Norway and Russia, which, because of this dispute, has been closed for scientific and commercial exploration, and industrial exploitation, for >40 years. However, since 2011, when a treaty agreement was signed between Norway and Russia, the former disputed zone has been the focus of increased exploration activity. This activity has been at least partly stimulated by the Norwegian Petroleum Directorate s (NPD) collection of several multichannel, 2D seismic reflections surveys, which have served to provide a tectonostratigraphic framework within which the hydrocarbon potential of the area can be assessed. Furthermore, analysis of magnetic data has allowed regional mapping of large salt structures (Gernigon et al., 2011), although such data cannot constrain salt composition or the detailed geometry and evolution of salt-tectonic structures. Much of these data remain unpublished and we therefore have a poor understanding of: (i) the composition, distribution and stratigraphic architecture of the Carboniferous-Permian salt, which, at least locally, is very reflective; (ii) the spatial and temporal relationships between Carboniferous-Permian salt and crustal rift basins; (iii) the style and timing of structures related to the flow of Carboniferous-Permian salt; and iv) the different triggers and drivers of salt mobilization the studied Barents Sea basins, highs and platform areas. A robust exploration model for the SNBS must be based on a solid understanding of the role Carboniferous-Permian salt played in the development of its constituent basins; herein lies the motivation for the 2-year NORSALT project. Fig. 2. Map of the Southern Norwegian Barents Sea showing key structural elements (Gernigon and Bronner, 2012) with the approximate boundary of the proposed study outlined in thick black dashes. BB, Bjørnøya Basin; BP, Bjarmeland Platform; CB, Central Barents High; FP, Finnmark Plaftorm; HB, Hammerfest Basin; KNC, Kalak Nappe Complex; LH, Loppa High; MFC, Måsøy Fault Complex; NB, Nordkapp Basin; ND, Norvarg; Dome; NH, Norsel High; NLHSZ, North Loppa High Shear Zone (informal); NP, Nordkinn Peninsula; OB, Ottar Basin (south); SaD, Samson Dome; SB, Sørkapp Basin; SD, Svalis Dome; SH, Stappen High; SHC, Palaeozoic Scott Hansen 2

3 complex (informal); Sw, Swaen Graben; TB, Tiddlybanken Basin; TFFC, Trøms Finnmark Fault Complex; TKFZ, Trollfjorden Komagelva Fault Zone; TN, Tanahorn Nappe; VH, Vestlemøy High; VP, Varanger Peninsula; VVP, Vestbakken volcanic province. BASIN EVOLUTION AND SALT TECTONICS Prior to deposition of Carboniferous-Permian salt, three main tectonic episodes shaped the SNBS: (i) Ordovician to early Devonian contraction (Caledonian Orogeny); (ii) Early Devonian extensional collapse; and (iii) Carboniferous extension and the development of graben and half-graben. During or slightly after Carboniferous extension (see below), salt with a highly variable spatial and thickness distribution was deposited across much of the SNBS. Our understanding of the stratigraphic architecture and salt-tectonic structural styles associated with mobilisation of this layer is based on relatively few detailed published studies, with the most recent being published by Nielsen et al. in 1995, ca. 20 years ago. Furthermore, Nielsen et al. (1995) focused solely on salt tectonics in the Nordkapp Basin. A paucity of detailed, regional studies, utilising high-quality seismic and borehole datasets, means that our understanding of the regional intrasalt stratigraphy and salttectonic evolution of the SNBS is poor; however, drawing on these previous studies, we below outline the current state-of-the-art public knowledge regarding these issues. The precise age of the salt in the SNBS is poorly constrained (Carboniferous-to-Early Permian; e.g. Nielsen et al., 1995; Early Permian; e.g. Gudlaugsson et al., 1998). Furthermore, the timing of salt deposition relative to the predominantly Carboniferous rift event is debated, with Nielsen et al. (1995) suggesting that salt deposition, at least in the Nordkapp Basin, post-dates rifting (i.e. it is postrift) and simply fills relict rift-related relief (Dengo and Røssland, 1992, Gudlaugsson et al., 1998). Due to intense post-depositional mobilisation, the initial salt thickness is similarly poorly constrained, with thickness estimated ranging from 2 km in the SW to up to 4-5 km in the NE of the Nordkapp Basin; this thickness change is ascribed to variations in basin subsidence, although it is not clear if this is pre- or syn-depositional (Nielsen et al., 1995). Regional (i.e. SNBS-wide) salt thickness variations are unknown. Most authors agree that salt mobilisation initiated in the late Early Triassic, particularly in the eastern basins of the Norwegian sector (e.g. Dengo and Røssland, 1992; Gabrielsen et al., 1992; Jensen and Sørensen, 1992; Koyi et al., 1993; Willoughby and Øverli, 1994), although the timing of initiation in basins to the west is generally younger (e.g. Faleide et al., 2008; Perez-Garcia et al., 2013) due to the overall tendency of westward-migrating strain throughout Mesozoic and Cenozoic times. Furthermore, the triggers for initiation remain uncertain (Nielsen et al., 1995) and may and will differ between different basins. Some authors suggest mobilisation in the Nordkapp Basin was driven by progradational loading and expulsion (Dengo and Rossland, 1992; Dore, 1992), whereas others argue that diapirs initiated as contraction-related pillows that eventually pierced their overburden (Koyi et al. 1993). Nielsen et al. (1995) challenge both these interpretations, instead arguing that basement-involved extension drove reactive diapirism (see also Gabrielsen et al., 1992; Jensen and Sørensen, 1992; Koyi et al., 1993). Irrespective of their genesis, during the latter part of the Early Triassic the diapirs pierced their thinned roofs, became emergent and started to grow by downbuilding (passive diapirism), with Lower Triassic (Ladinian) strata filling flanking minibasins. The presence of a major unconformity in the Anisian (top Lower Triassic unconformity of Koyi et al., 1993), above which strata are relatively flat, suggests that the salt began to weld at this time. However, active diapirism locally continued until the end of the Triassic due to overburden contraction and diapir squeezing (Nielsen et al., 1995). During the Late Cretaceous, regional extension related to opening of the North Atlantic resulted in updip overburden extension, and kinematically linked downdip diapir squeezing and roof arching (Nielsen et al., 1995). After shortening and active diapirism, the diapirs were buried by c. 1.5 km of Tertiary strata, before a final phase of active diapirism occurred during the middle Tertiary in response to regional contraction and strike-slip movement, which led to further diapir squeezing, perhaps related to ongoing opening of the North Atlantic. 3

4 In summary and as stated above, our present understanding of salt tectonics in the Norwegian Barents Sea is poor and based on only very few studies, conducted ca. 20 years ago, on relatively poor-quality data. However, the availability of new, high-quality data, and the development of new concepts in salt tectonics, mean the time is right to reappraise the salt stratigraphy and salttectonic history of the SNBS and to reassess their roles in the development of the associated petroleum system. Preliminary analysis by the authors of this proposal suggests that different salt pillows, rollers, and diapirs had variable timing, triggering mechanisms, and subsequent histories. Some of these structures are indeed associated with extension, but overburden geometries show that others are consistent primarily with loading and inflation or even contraction. These differing structural styles formed at different times and resulted in different trapping styles, thus it is critical to establish the key drivers of salt-tectonics across the basin and how these structural styles vary. Seismic profiles also indicate major lateral and vertical changes in intrasalt seismic facies variability, suggestive of major lateral and vertical changes in the composition and, therefore, internal reservoir, source and seal potential as well as salt mobility. Moreover, improvements in seismic imaging also suggest there are differences in the timing of basement-involved extension relative to salt deposition. Finally, structural restorations and sophisticated physical models have not yet been used to test hypotheses regarding the genesis of salt-tectonic structural styles. AIMS This project has three key aims: (i) to evaluate the stratigraphic architecture of the Carboniferous- Permian salt; (ii) to determine the relationship between Carboniferous-Permian salt and basement structure; and (iii) to outline the key salt-tectonic structural styles within the SE Norwegian Barents Sea and the principal phases and drivers of salt-related deformation. All three topics are interrelated but will be addressed separately here. Stratigraphic and mechanical architecture of the layered evaporite sequence (LES) Salt is typically poorly reflective in seismic reflection data. However, Upper Carboniferous-to-Permian evaporites in the SNBS are, at least locally, very reflective (Fig. 3). Studies from other salt basins indicate that such reflectivity principally arises due to intrasalt lithological variability, related to the presence of different evaporitic (e.g. halite, anhydrite) and often non-evaporitic (e.g. clastics, carbonates) rocks. Establishing the composition and stratigraphic variability, both vertically and laterally, within the LES is critical to determine how many relatively mobile levels there are within the LES, whether there are interbedded source-rock, reservoir and seal intervals, and how the mechanical stratigraphy impacts the salt-tectonic evolution and thus trap development within the SNBS. Fig. 3. Seismic profile across the western flank of the Fedynsky High showing the LES and its relationship to basement-involved normal faults. What is termed brecciation may instead represent carbonate buildups bounding the small evaporite basin. Source: NPD website. We will use seismic reflection and borehole data (see below) to constrain the distribution and stratigraphic architecture of and lateral lithological and mechanical variability within the LES. More specifically, we will assess if vertical and lateral spatial variations in reflectively are related solely to lithology, such as the presence of intrasalt carbonate 4

5 buildups or clastic-rich layers, or whether other factors, such as bedding disruption during deformation or salt dissolution and formation of salt karst, played a role. Furthermore, thickness and compositional variations in the LES will have strongly controlled its propensity to mobilise and generate large salt structures. Spatial and thickness distribution of the LES Preliminary seismic mapping indicates a complex relationship between the LES and underlying basement relief. In many cases the LES is thickest and the salt structures are largest within depocentres bound by basement-involved normal faults (Fig. 4); in others the LES appears to simply thicken into a depocentre along with presalt strata. Thus, a key question relates to the temporal relationship between basement-involved tectonic extension and salt deposition. More specifically, was the LES deposited during (i.e. it is synrift) or after (i.e. it is postrift) basement-involved extension, or did deposition span both tectonic episodes? And does the relative timing between rifting and LES deposition vary spatially across the study area? These are critical questions because the style and magnitude of syn-depositional tectonics will impact the composition, thickness and hence reservoir and seal potential of the LES, as well as the initiation and evolution of salt structures. Fig. 4. Seismic profile across the northeastern Nordkapp Basin, showing the abrupt thickening, and thus probably synrift origin, of the evaporite sequence. Source: NPD website. Initiation and evolution of salt-related deformation Because the salt-tectonic geology of the SNBS is so poorly known, our first task will be to establish the distribution of the main salt-tectonic structures in different basins (e.g. diapirs, rollers, salt-cored anticlines and allochthonous canopies; Fig. 5). We will then focus on what caused this distribution. For example, what triggered the salt mobilisation and deformation, and how did the different structures evolve in time and space? Did ongoing crustal extension trigger and influence early salt movement? How did northward progradation of Triassic deltas (e.g. Glørstad-Clark et al. 2011) impact the development of salt structures? How much deformation was driven by gravitational 5

6 failure? What was the origin and distribution of intra-triassic contraction? How are the late thinskinned contractional structures related to the thick-skinned inversion structures? How did the different graben orientations impact inversion? Ultimately, we will establish how the different styles and growth histories of salt-tectonic structure impacted trapping, hydrocarbon migration and reservoir deposition. GEOGRAPHICAL SCOPE, DATASET AND METHODOLOGY The study area will cover a large portion of the SNBS where salt tectonics was active. This will extend from the Norwegian-Russian boundary in the east across the Tiddlybanken and Nordkapp Basins, the Maud and Hammerfest Basins, to the Tromsø and Sørvestsnaget Basins in the west (Fig. 2). The area is deliberately large so that we can determine local and regional controls on evaporite stratigraphy and salt-tectonic evolution. Furthermore, a large study area means that results arising from our study will be of interest to a wide range of companies, who may have interest in specific parts of the SNBS. To undertake this study we require 2D and 3D seismic reflection data. For the regional analysis we will primarily use 2D seismic surveys NPD-BA-11 and NPD1201, collected in 2011 and 2012 respectively by the NPD, which covered the SNBS. These seismic data will be supplemented by publically available, 2D seismic reflection data acquired by the NPD during ; although of lower-quality than more recently acquired data, they provide regional coverage of the SNBS. These legacy data have recently been processed and interpreted by MCG Geophysical AS and Exploro Petroleum AS; we are currently trying to get access to these data such that we can utilise them in the proposed project. If possible, we will also utilise the Barents Sea Group Shoot 3D seismic reflection survey acquired by WesternGeco and PGS on behalf of Statoil and project partners. These data cover the easternmost SNBS, in part of the formerly disputed zone. Together these data will provide relatively high-resolution spatial coverage of the SE Norwegian Barents Sea, allowing us to: (i) define the presalt structure and its relationship to the LES; (i) map the distribution of and seismic facies variability within the LES; (iii) map salt-tectonic structural styles; and (iv) constrain overburden stratal patterns, which will allow us to determine the type and timing of salt-tectonic triggers and ongoing drivers. Fig. 5. Seismic profile across the Tiddlybanken Basin showing salt-tectonic structural styles. Overburden geometries suggest diapirism was triggered by Middle Triassic contraction. Source: NPD website. 6

7 We will also require borehole data. These data will allow us to: (i) tie seismic reflection events to physical stratigraphy; (ii) directly constrain the origin of seismic expression variability within the LES; (iii) map the stratigraphic architecture of the LES; (iv) ground-truth seismicallydefined thickness variations in the LES; and (v) determine overburden thickness and facies variations that record growth of salt-tectonic structures. Interpretations arising from our analysis of seismic and borehole reflection data will form the foundation of quantitative structural restorations. These will include decompaction and variable Airy isostatic corrections in order to constrain the evolution of salt thickness over time (Rowan, 1993). The results will demonstrate the initiation and evolution of different types of salt structures and the role of basement deformation in the tectonic history of the basin. We will also undertake scaled physical modelling (e.g., Fig. 6) with project partners at the Geomodels Research Institute at the University of Barcelona, Spain. Our models will be specifically designed to answer key questions arising from our seismic and structural analysis. For example, although there are existing models that examine the initiation and evolution of salt diapirs triggered by progradational loading of salt that thins over a landward-dipping basement step, there are none that include salt that thickens over a basinward-dipping step into a graben. This geometry is observed and played a key role in several locations within the SNBS. Fig. 6. Physical model showing the development of salt-tectonic structures related to sedimentary loading and expulsion. Image courtesy of Oriol Ferrer and the Geomodels Research Institute at the University of Barcelona. RESOURCES AND BUDGET Jackson, Rowan, Rotevatn and Giles will be co-pis of the project. Jackson s expertise is in extensional tectonics, salt-tectonic analysis, salt stratigraphy and petroleum systems analysis. Rowan s expertise is in salt-tectonic analysis, seismic interpretation, salt-sediment interaction and structural restoration. Rotevatn s expertise is in structural geology, petroleum systems analysis and Barents Sea regional geology. Giles expertise is in carbonate-evaporite sedimentology and stratigraphy and saltsediment interaction. This research team has unsurpassed experience in the use of subsurface data to assess the structure, stratigraphy and petroleum systems development of salt-bearing sedimentary basins. The Co-PIs will be assisted by three Post-Doctoral Research Associates (PDRAs); two will be based at Imperial College and one at the University of Bergen. Note that the technical level and volume of work required in this project are significant, thus the three main academic posts require staff already holding a doctorate degree (i.e. PDRAs). The two Imperial College-based PDRAs will focus on: (i) the salt-tectonic evolution of the Nordkapp and Tiddlybanken basins (PDRA-1) and surrounding platforms; and (ii) the regional composition and stratigraphic architecture of Carboniferous-Permian salt (PDRA-2). The University of Bergen PDRA (PDRA-3) will focus on the salttectonic evolution of the area west of the Nordkapp Basin, including the Hammerfest, Maud, Trømso and Sørvestsnaget basins, and the Svalis and Loppa highs. To ensure knowledge sharing between the co-pis and PDRAs, the research budget includes costings for travel between institutions to allow faceto-face meetings. The estimated total cost for this two-year project will be: 777,394 (9,293,988 NOK). An institutional breakdown is provided below: 7

8 Imperial College* 1. Staff (PDRA-1, PDRA-3, co-pis Jackson and Rowan): 574, Computing: 14, Travel and accommodation (e.g. conference, sponsor meetings): 15, Consumables (e.g. lab costs, open access publishing): 33,097 University of Bergen* 1. Staff (PDRA-2, co-pi Rotevatn): 183,270 University of Barcelona 1. Physical modelling: 20,000 *NORSALT will be supported by MSc and MSci student research projects undertaken at Imperial College and the University of Bergen. These students will complete short-term (typically 3-6 months) sub-projects that will compliment and feed into the main project objectives. DELIVERABLES Project results will be delivered to the sponsors in a number of formats: (i) seismic interpretation deliverables, such as interpreted profiles, time-structure maps, isopach maps, structural element maps, LES facies maps and fault sticks, will be delivered in X,Y,Z (.ascii) format; these will be suitable for loading into most seismic interpretation systems; (ii) input data for stratigraphic correlations (e.g. formation tops or picks within previously undefined parts of the stratigraphy, such as within the LES) will be delivered in X,Y,Z (.ascii) format; these will be suitable for loading into most seismic interpretation systems; (iii) structural restorations in X,Y,Z (.ascii) format; (iv) the final project report containing the key final results and associated material (i.e. conference presentations, papers) will be delivered in an atlas- or wiki- style webpage; and (v) progress updates will be provided in two formats; (i) at an annual workshop-style meeting, to be held at the NPD offices in Stavanger, Norway; and (ii) in 6-monthly updates to the webpage. Note that the seismic interpretation and stratigraphic analysis part of the project will be undertaken in Schlumberger s Petrel software suite, hence a Petrel project containing the final subsurface interpretation material can be provided on request. Theses reports generated by MSc and MSci students will also be made available to project sponsors. The NORSALT project will deliver an improved understanding of: (i) the salt tectonic evolution and structure of the Norwegian Barents Sea, which will greatly help the sponsor companies appraise the petroleum potential of the constituent basins; and (ii) the stratigraphic variability and petroleum systems importance of Carboniferous-Permian salt. More generally, the NORSALT project will generally increase the general salt-tectonic competence within the sponsor companies, which can then be applied more globally to other petroliferous, salt-bearing sedimentary basins. We foresee follow-on, FORCE-supported projects focused on other salt-bearing sedimentary basins along the Norwegian margin (e.g. Halten Terrace, Norwegian Central Graben). RESEARCH PLAN Here we outline an initial research plan, with a planned startup date of January 1 st, Note this plan can and undoubtedly will be refined based on the specific business needs of the sponsor companies and on the ideas generated during the course of the project. Year 1 1. Engagement with sponsors to further refine business needs 2. Data receipt, loading and QC 3. PDRA-1 and 3 a. Generation of synthetic seismograms to establish seismic-to-well tie 8

9 b. Use regional 2D seismic reflection data to establish regional salt-tectonic structural framework within respective basins; focus on large-scale salt tectonics geometries and relationship to main pre- and postsalt structures and stratigraphic architectures c. Initial development of regional salt-tectonic structural style atlas and associated structural elements map 4. PDRA-2 a. Initial stratigraphic analysis of well data; focus on delineation of main salt and intrasalt stratigraphic packages b. Use of 2D seismic reflection data to define main intrasalt seismic-stratigraphic packages (N.B. may require generation of synthetic seismograms depending on final areal extent of study and well data availability) c. Interact with PI Giles at UTEP for advice/guidance on stratigraphic aspects 5. Design and initiation of physical models with University of Barcelona project partners 6. End-of-year workshop and reporting in Stavanger, Norway, hosted by the NPD Year 2 1. Agree Year 2 plans and deliverables based on evolving business needs of sponsors 2. PDRA-1 a. Complete interpretation of regional 2D seismic reflection data and finalise salttectonic structural framework for the Nordkapp and Tiddlybanken basins b. Use 3D seismic reflection data ( Group Shoot ) in the easternmost Norwegian Barents Sea to constrain detailed salt-tectonic structure and evolution of the Nordkapp-Tiddlybanken area c. Completion of Nordkapp-Tiddlybanken component of the salt-tectonic structural style atlas d. Structural restorations of key seismic profiles 3. PDRA-2 a. Use regional 2D and 3D ( Group Shoot ) seismic reflection data to conduct detailed intrasalt seismic facies mapping and to further refine LES stratigraphic model b. Petrophysical analysis of salt physical properties (e.g. porosity, permeability) and assessment of LES source, reservoir and seal quality c. Continued interaction with PI Giles at UTEP 4. PDRA-3 a. Complete interpretation of regional 2D seismic reflection data and finalise salttectonic structural framework for the area west of the Nordkapp Basin b. Completion of the salt-tectonic structural style atlas for the western Norwegian Barents Sea c. Structural restorations of key seismic profiles 5. Continuation and completion of physical models. 6. End-of-project workshop and reporting in Stavanger, Norway hosted by the NPD FORCE NETWORK GROUP INVOLVEMENT Because of its integrative nature, combining geological and geophysical data and methods to explore structural geology and stratigraphy, this project will be of special interest to the Structural Geology network group ( salt-tectonic evolution of sedimentary basins ) and the Sedimentology and Stratigraphy network group ( stratigraphy of evaporite-bearing sedimentary sequences ). The project may also be of interest to the Geophysical Methods network group ( impact of salt structure and composition on near-salt seismic imaging ). The project will thus be of interest to a significant part of the FORCE membership. 9

10 BUSINESS MODEL We envisage that the project will be run as a Joint Industry Project (JIP). As such, we seek funding from a consortium of companies with specific strategic interest in the Norwegian Barents Sea, or with a general interest in the salt stratigraphy and salt-tectonic evolution of sedimentary basins. Joining a JIP will reduce costs for individual companies. A JIP approach, which shares the financial burden across several companies, is consistent with that recently implemented by Statoil for their Barents Sea Group 3D Seismic Shoot. 10