PRESENTACION ALMACENADORAS •
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The hydrocarbon hydrocarbon reservoir formations on Statfjord lie at depths of 2 500! 000 "etres# They consist of sandstones$ sandstones$ %ith the oil and &as held in in pores bet%een bet%een the individ'al sand sand &rains# the fluvial-channel and delta-plain Lower Jurassic Statfjord Formation. Formation.
El reservorio de (C de la for"acion Statf)ord yace a 'na prof'ndidad de 2500!000 "# CONSISTE EN ARENISCAS CON ACEITE * +AS EN ,OS POROS# El canal -'vial y el delta de la for"aci.n Statf)ord del )'r/sico te"prano#
shallow-marine Lower Jurassic Cook Formation sandstones Formation sandstones Toarcian) is dominated by sand-stone tongues that interfinger The Cook Fm (Pliensbachian to Toarcian) with the Drake mudstones at several distinct stratigraphic levels. Typically Typically each of the sandstones are characterized by a lower zone of sharp-based sharp-based upward-coarsening shoreface sand and siltstones and an upper erosive surface consisting of thin tidal flat and thick deltaic!estuarine deltaic!estuarine sandstones. ARENISCAS DE UN AMBIENTE MARINO POCO PROFUNDO DE LA FORMACION COOK "#$%&'"' *$ &%T$#"+"% ,% *D'T,%$ D$ +" . Drake
Middle Jurassic sandstones of the Brent Group$
delta sandstones sandstones from from the Middle Jurassic Brent Group, Group,
The reservoirs for" for" a thic clastic clastic %ed&e co"prisin& co"prisin& laterally e1tensive e1tensive interconnected interconnected -'vial$ deltaic and coastal depositional syste"s %ith porosities and per"eabilities ran&in& fro" 20!0 and 50500"3 respectively respectively at shallo% depths 4+iles et al#$ 6627# In the northern North Sea$ the 8iddle 9'rassic reservoirs are represented by the :rent +ro'p$ %hich co"prises the Tarbert 4yo'n&est7$ Ness$ Etive$ Rannoch and :roo" ;or"ations 4
7# The basal :rent is typically 'pper shoreface sandstones %hiles the 'pper part of the &ro'p is represented by trans&ressive sandstones 4+a'tier$ 20057# ARENISCAS EN A8:IENTE 3E,TAICO 3E, +R?PO :RENT EN E, 9?RASICO 8E3IO ,os dep.sitos for"an 'na e1tensa capa lateral cl/stica interconectando siste"as deposicionales deposiciona les costeros -'viales$ deltaicos con porosidades y per"eabilidades oscilan entre 20!0 y 50500"3$ respectiva"ente$ a poca prof'ndidad prof'ndidad 4+iles et al#$ 6627#
GENERADORAS
T%o T%o "ain so'rce so'rce rocs occ'r occ'r in the st'dy area# area# :oth are "e"bers "e"bers of the
3ra'pne ;or"ation@i""erid&e Clay
The 3ra'pne ;" is the "ain hydrocarbon so'rce in the so'rce area# It is typically a bro%nish blac$ "edi'" to dar olive &rey$ noncalcareo's "'dstones$ %hich are locally silty and "icaeo's 4@'bala et al#$ 200!7# The thicness of the 'nit is "ostly bet%een 50250 " b't "ay locally e1ceed 200 "# I""at're @i""erid&e Clay or&anic "atter consists "ostly of Type II ero&en 4Billia" and 3o'&las$ 6=07 and is rated as an e1cellent oil &eneratin& so'rce roc &eneratin& &as at hi&her "at'rity levels 4+o$ 6=!7# Type II ero&en is a "i1t're if bacterially de&raded al&al debris of "arine plantonic ori&in and de&raded h'"ic "atter of terri&eno's ori&in 4Cornford$ 66=7# ho%ever in the &raben areas s'ch as the northern North Sea$ deposition occ'rred belo% %ave base inan ano1ic environ"ent %ith hi&h bio&eneic prod'ctivity and sedi"entation rates 4Cornford$ 66=7# 3ra'pne ;or"aci.n Es tDpica"ente l'titas de color "arr.n ne&ro$ &ris "edio y osc'ro$ "'dstone no calc/reos$ 'e son local"ente li"osa Arcilla de @i""erid&e "ateria or&/nica se co"pone principal"ente de tipo II er.&eno y est/ considerado co"o 'na e1celente f'ente de &eneraci.n de &as.leo de &eneraci.n de roca en los niveles de "ad'reF "/s altos# Tipo ero&eno II es 'na "eFcla de restos de al&as si de&radado por bacterias planct.nicas de ori&en "arino y "ateria hG"ica de&radada de ori&en terrD&eno#
(eather ;or"ation
The 'nit co"prises dar &rey silty "'dstones %ith interbeded carbonate bands# The thicness of the for"ation is very variable b't can be as "'ch as 000 " in the 7 indicate that it is locally oil prone in the eastern -ans of the
The coal intervals %ithin the Ness ;"# of the 8iddle 9'rassic :rent +ro'p are also considered as i"portant so'rce rocs for &as &eneration$ especially in the North
,a 'nidad co"prende l'titas li"osas de color &ris osc'ro intercaladas de carbonatos# ,a ;or"aci.n (eather es tDpica"ente prod'ctor de &as$ pero los est'dios realiFados por +or"ly
et al# 466>7 indican 'e es propensa a nivel local de aceite en los -ancos orientales de los viin&os +raben# ,os intervalos de carb.n dentro de la Ness ;"# del 9'r/sico 8edio +r'po :rent ta"biHn son considerados co"o i"portantes rocas f'ente para la &eneraci.n de &as$ especial"ente en el Norte de
SELLO The Drake Fm (Toarcian to /a0ocian) consisting of silt and mud-stones were deposited during a continued rise in the relative sea level and the formation acts as a seal towards the underlying ook sandstones.
Fm Drake consiste en limos m!"stone "e#osita"os "!rante el ascenso "el ni$el "el mar The Stat%&or" '# is sub-divided into three formations (#aude $iriksson and %ansen). The upper boundary of the 'tatf0ord 1p is sharp against the fully marine mudstones of the overlying Dunlin 1roup that could act as a regional seal. 'r!#o Stat%&or" el limite s!#eror "el (r!#o es %!erte contra el m!"stone marino "el (r!#o D!nlin) *!e #o"r+a act!ar como !n sello re(ional, The Ness Fm (/a0ocian to /athonian) consists of an association of coals mudstones siltstones and fine to medium sandstones. haracteristic features are numerous rootlet horizons and a high carbonaceous content. The upper boundary is the change to the more massive and cleaner sandstones of the overlying Tarbert m. The formation is interpreted to represent delta plain or coastal plain deposition. The amount of silt and mudstones in the formation may act as a local seal. The %ess m shows large thickness variations ranging from 23 m up to about 456 m. Fm Ness consiste en !na asociaci-n "e car.on) l!titas) limolitas areniscas %inas a me"ianas, Los ras(os caracter+sticos son n!merosos hori/ontes con alto conteni"o car.onoso, El l+mite s!#erior es el cam.io en las areniscas m0s masi$as m0s lim#ias "e la s!#raacente Tar.ert Fm, La %ormaci-n se inter#reta #ara re#resentar la "e#ositacion "e !na #lanicie "e "elta o !na llan!ra costera, La canti"a" "e limo m!"stones en la %ormaci-n #!e"e act!ar como !n sello local,
RAM!A (o%ever "ost trappin& "echanis"s are provided by rotated fa'lts blocs sealed by ne &rained post rift sedi"ents %hich drape onto the str'ct'res to for" seals ,ateral trappin& and sealin& is also for"ed %here reservoir rocs are )'1taposed %ith non reservoir rocs at fa'lt contacts 4+a'tier$ 20057# The sealin& capacity of the cap rocs is li"ited by overpress'res %ithin the st'dy area 4@arlsson$ 6=J7 and "ost seals are close to hydra'lic fract're
A pesar de "ue la ma#oria de las trampas se proporcionan por fallas $lo"ues rotados sellados por sedimentos %nos post&rift especiali'adas "ue cu$ren las estructuras para formar sellos El entrampamiento lateral # sellado tam$i(n se forma cuando las rocas del #acimiento se #u)taponen con las rocas "ue no son del #acimiento en los contactos de falla* La capacidad de sellado de las rocas tapa est+ limitada por el e)ceso de presiones dentro del +rea de estudio # la ma#or,a de los sellos est+n cerca de la fractura hidr+ulica
IN;OR8ACIKN RESER-O.R ROC/S
The +'llfas reservoirs consist of Middle Jurassic sandstones of the Brent Group$
and ,o%er 9'rassic and ?pper Triassic sandstones of the Statfjord Group and Coo0 and Lunde 1ormations#
Oil in the overlyin& Shetland +ro'p and ,ista ;or"ation is also bein& recovered# The reservoirs lie at a depth of L002 000 "etres# The +'llfas reservoirs are located in rotated fa'lt blocs in the %est and a str'ct'ral horst in the east$ %ith a hi&hly fa'lted area in bet%een# PRO3?CTION ;RO8 T(E ;IE,3M The Nor%e&ian Petrole'" 3irectorate http%%%#norspetrole'"#noenprod'ctioneld &'llfas The reservoir consists of delta sandstones from the Middle Jurassic Brent Group, shallow-marine Lower Jurassic Cook Formation sandstones, and the fluvial-channel and delta-plain Lower Jurassic Statfjord Formation. https://en.wikipedia.org/wiki/Gullfaksoilfield
The main reservoirs of the Gullfaks, !se"erg and Statfjord fields are in the large Brent delta that formed in the Jurassic. There are also large reservoirs in sand that was deposited on alluvial plains during the Triassic #eriod $the %norre field&, in shallow seas in the Late Jurassic $the Troll field& and as su"sea fans during the #alaeogene #eriod $the 'alder field&. (n the southern part of the )orth %ea, thick la*ers of chalk composed of microscopic calcareous form an important reservoir rock, as in the +kofisk ield.
The )orwegian #etroleum irectorate http://www.norskpetroleum.no/en/petroleum-resources/petroleumformation/
The Cook Fm (Pliensbachian to Toarcian) is dominated by sand-stone tongues that interfinger with the Drake mudstones at several distinct stratigraphic levels. Typically each of the sandstones are characterized by a lower zone of sharp-based upward-coarsening shoreface sand and siltstones and an upper erosive surface consisting of thin tidal flat and thick deltaic!estuarine sandstones. http7!!www.npd.no!en!Publications!#eports!ompiled-,2-atlas!5-The-%orwegian-%orth-'ea!541eology-of-the-%orth-'ea!The-Dunlin-1roup!
Oil and 2as production
The hydrocarbon reservoir formations on Statfjord lie at depths of 2 500! 000 "etres# They consist of sandstones$ %ith the oil and &as held in pores bet%een the individ'al sand &rains# These hydrocarbonbearin& sedi"ents %ere all deposited in the 9'rassic era$ abo't 50 "illion years a&o# Ro'&hly =0 000 barrels of oil per day are prod'ced by the Statf)ord ?nit licence &ro'p$ %hich 'nites all the licences and incl'des all three Statf)ord platfor"s and satellite elds tied in to Statf)ord C# The prod'ction record for a sin&le day on Statf)ord %as set on J 9an'ary 6=L$ %hen =50 20> barrels %ere prod'ced# Ro'&hly fo'r "illion c'bic "etres of &as are e1ported daily by the Statf)ord ?nit#
http%%%#statoil#co"eno'roperationse1plorationprodncsstatf)ordpa&esdefa'lt#asp1
Tarbert Formation
There is controversy exists regarding the boundary between Ness and Tarbert Formation and depositional environment consequently. The group of authors mainly Pettersen et al. (1!" distinguish the boundary between those formations as marine transgressive event that separates these two different phases of delta building. #lternatively$ %ielding et al. (1!"$ &raue et al. (1'" propose that marine transgressive event prior to Tarbert deposition in Ness time. )ince the previous research that had been done on earlier stages of the thesis pro*ect$ an author confines the assumption of earlier transgressive event$ in particular Ness time being responsible for sedimentation patterns within the +pper Ness. ,onsequently from that point of view the Tarbert formation is interpreted as pure controlled by the marine environment. -ithology varies from shales$ siltstones and coal beds to mediumto coarsegained sands in which calcite cementation is found.
:ased on revie% of the available %ell lo&s so"e of the co""on +R response %ere analyFed in order to perfor" the Table listed belo%#
8ASTERS T(ESISM Evidence for tectonic control deposition of the :rent +ro'p$ northern North Sea SEA, ROC@ The Drake Fm (Toarcian to /a0ocian) consisting of silt and mud-stones were deposited during a continued rise in the relative sea level and the formation acts as a seal towards the underlying ook sandstones. The upper boundary of the Drake m is marked by the more sandy sediments at the base of the deltaic /rent 1roup. +ocally there is some sand towards the top of the Drake m.
The Stat%&or" '# is sub-divided into three formations (#aude $iriksson and %ansen). The upper boundary of the 'tatf0ord 1p is sharp against the fully marine mudstones of the overlying Dunlin 1roup that could act as a regional seal.
Nor%e&ian Petrole'" 3irectorate
The Ness Fm (/a0ocian to /athonian) consists of an association of coals mudstones siltstones and fine to medium sandstones. haracteristic features are numerous rootlet horizons and a high carbonaceous content. The upper boundary is the change to the more massive and cleaner sandstones of the overlying Tarbert m. The formation is interpreted to represent delta plain or coastal plain deposition. The amount of silt and mudstones in the formation may act as a local seal. The %ess m shows large thickness variations ranging from 23 m up to about 456 m.
8888888888888888888888888888888 8888888888888888888888888 +lithostratigrapic nomenclature of the *9 %orth 'ea: /ritish 1eological 'urvey of the *9 ,ffshore operators "ssociation
!#2# So'rce Rocs T%o "ain so'rce rocs occ'r in the st'dy area# :oth are "e"bers of the 00 "&&TOC 4@'bala et al#$ 200!7# The environ"ent of deposition of the 'nit has been of "'ch debate$ ho%ever in the &raben areas s'ch as the northern North Sea$ deposition occ'rred belo% %ave base inan ano1ic environ"ent %ith hi&h bio&eneic prod'ctivity and sedi"entation rates 4Cornford$ 66=7# (eather ;or"ation The 'nit co"prises dar &rey silty "'dstones %ith interbeded carbonate bands# The thicness of the for"ation is very variable b't can be as "'ch as 000 " in the 7 indicate that it is locally oil prone in the eastern -ans of the
typically bet%een 22#5 4+o$ 6=!7# (ydro&en indices are correspondin&ly lo% d'e to a &reater proportion of terrestrial h'"ic ero&en#
raps and Seals There is &reat diversity in the traps and seals in the northern North Sea to e'ally "atch the variety in hydrocarbon acc'"'lations# (o%ever "ost trappin& "echanis"s are provided by rotated fa'lts blocs sealed by ne &rained post rift sedi"ents %hich drape onto the str'ct'res to for" seals 4+a'tier$ 20057# In the
