Reservoir characterization of jurassic sandstones of the. Petroleum geology the norwegian petroleum directorate. Determining mineral stability and co2sequestering capacity of. The properties of a petroleum reservoir rock are very similar to those of an aquifer since both petroleum and water can be contained within and move between its pore spaces and fractures. Pdf peristeritic plagioclase in north sea hydrocarbon. The triassic lunde formation and the lower jurassic statfjord formation of the snorre field northern north sea are investigated in this study. Carboniferous petroleum systems around the mid north sea. At such depths the reservoir quality is critical, due to both compaction and diagenetic processes.
Petroleum prospectivity of the principal sedimentary basins on the united kingdom continental shelf. Pdf north sea reservoir characterization using rock. Reservoir quality of deeply buried sandstones a study of. The most interesting and perhaps impressive aspects of carbonate reservoir rocks are their fossil content. In each test, the sample was coupled with an array of 16 piezotransducers to measure ultrasonic wave velocities and monitor acoustic emissions ae. Effect of reservoir depletion and pore pressure drawdown on.
This study investigates the utility of north sea oil field data to construct reservegrowth models. In the north it is bounded by the continental shelf edge. Deciphering organicinorganic processes by hydrogeochemical modeling. North sea reservoir characterization using rock physics, seismic attributes, and neural networks. This change is reflected in this new 4th edition, which has been significantly expanded to accomodate additional material. Diagenesis and reservoir quality of the hugin formation. The reservoir consists of multilayered lower and middle jurassic sediments containing a stoiip of 480 mmbbl of high wax crude oil. The most important reservoir rocks are the lower permian sandstones of the. Petroleum geology of the north sea can still be highly recommended to industry geologists without prior knowledge of the region, to university teachers looking for a case study in a petroleum geology or basin analysis course, and to undergraduates on the receiving end of such courses. This study presents reservoir characterization of middle and upper jurassic sandstones by using petrophysical analysis, compaction study and rock physics diagnostics with data from 26 exploration wells from the johan sverdrup field, central north sea. Techniques for extracting threedimensional volume attributes have been applied to a 3d seismic data volume of the f3 block in the dutch sector of the north sea.
In the north sea, chalk became a reservoir for oil and gas by a combination of fortunate circumstances. The north caspian basin is a petroleumrich but lightly explored basin located in kazakhstan and russia. North sea chalk hydrocarbon fields are all located over thick areas of. Virtually all significant oil and gas accumulations in the northern north sea are believed to have been generated within certain finegrained, organiccarbonrich marine strata of late jurassic and earliest cretaceous age. Set of fractures may control migration and the interpretation is very important in correlation of sources, migration pathways, reservoir and seal. Thus, it has been found that instantaneous attributes make it possible to highlight the different properties of reservoir rocks. So sandstone reservoir rocks are the result of a number of varied processes that can occur on dry land as well as beneath the sea. Berthierine formation in reservoir rocks from the siri oilfield danish north sea as result of fluid rock interactions. The acquisition of digitized representations of rock microstructures has been established in the workflow for investigation of petrophysical, material, and transport properties. The downthrown, western a block is dissected by high angle, tensional faults while the upthrown, eastern b block is relatively unfaulted. Norwegian sector of the north sea, the utsiraskade aquifer. Across the north central and northern north sea, the chalk group is a major seal unit, overlying a number of blocks of reservoir rocks and preventing their fluid contents from migrating upwards. Exploration in the uk southern north sea rotliegend transition zone by hubert j. The reservoir is a chalk formation that exhibits porosities in the range of 25 to 48%.
Pdf the complex burial and diagenetic histories of the jurassic fulmar and triassic skagerrak sandstones in the uk central north sea. The beatrice field, block 1a, uk north sea geological. Jurassic and earliest cretaceous age in and adjacent to the viking graben of the northern north sea. The north sea oil and gas provinces contain the majority of the uks fields and. The reservoir geochemistry of the eldfisk field, norwegian north sea d. Petroleum reservoir an overview sciencedirect topics. Reservoir simulation in a north sea reservoir experiencing.
The downthrown, western a block is dissected by high angle, tensional faults while the. It was evident that there was a continuation beneath the north sea of the permian the producing reservoir at slochteren, the mesozoic and also. Sedimentary rocks that are well cemented have only small voids between grains and hence low porosity. North sea and as a result has the greatest potential for co2 storage. The largest of these fields is the raman west batiraman, which contains about 2 b. Seismic surveying uses seismic waves propagated in the crust of the earth to identify and map rock structures that are likely to contain petroleum reservoirs, such as basins and traps. It is a broad, domal, saltinduced structure of 750 ft closure, cut by a major, nnessw striking, normal fault. Synrift the upper jurassic synrift play is currently, and will continue to be, one of the.
The geological picture at that time was assessed by the industry about as follows. All types of rock igneous, sedimentary, metamorphic can act as reservoir rocks if it can accommodate and drain hydrocarbons. North sea basinal area, europe an important oil and gas. These provinces comprise the north sea oil province, the north sea gas province, the irish sea and the atlantic margin figure 4. Since 2001, he has worked with mi energy corp on three oil field development projects located onshore ne china. The reservoir rock appears in different forms, from loose sands to dense and tight rocks. When likely structures are found, other technologies are applied to obtain additional information about the. An assessment of carbon sequestration potential in the uk. The beatrice field was discovered in 1976 in block 1l30a within the inner moray firth basin. The south brae field, block 167a, uk north sea geological.
Over 20 years of petroleum production has resulted in a 2124 mpa reduction in reservoir pore pressure. Reservoir rocks will mobilize maximum compaction drive if they yield in this manner, but may also suffer a permeability loss due to the decrease in porosity. The beryl field, the sixth largest oil field in the uk sector of the north sea, is located within block 9 in the westcentral part of the viking graben. Pdf berthierine formation in reservoir rocks from the siri. The remaining and future petroleum potential of these provinces is summarised below. Source and reservoir rocks characterization of the ling. Hugin formation located in the sleipner field area fig. Reservoir geology of the paleocene forties sandstone member in the fram discovery, uk central north sea tertiary deepmarine reservoirs of the north sea region termination geometries and reservoir properties of the forties sandstone pinchout, east central graben, uk north sea.
The reservoir sequence comprises 1100 ft of hettangian lower jurassic to callovian middle jurassic sandstones, siltstones and claystones. The availability of these data open the way for the development of methods that directly predict effective properties based on digitized topological information. The block was awarded in 1971 to a mobil operated partnership and the 91 discovery well was drilled in 1972. A survey of the initial condition of forty production wells from ten north sea fields was. Figure 2 location of gas fields in the southern north sea. The reservoirs are composed of coarse clastic sediments of the upper jurassic brae formation, which were deposited by turbidity currents and debris flows in a submarine fan setting. Exploration of offshore petroleum prospects involves various technologies. The skarfjell oil and gas discovery, situated 50 km north of the troll field in the ne north sea, was discovered by well 3597 and was appraised by three additional wells operated by wintershall, in the period 201214. Kimmeridgian shales total petroleum system of the north. Petroleum systems analysis petroskills geology training. Pdf new insights on subsurface energy resources in the southern. Reservoir geology of the paleocene forties sandstone member in the fram discovery, uk central north sea tertiary deepmarine reservoirs of the north sea region volund field.
This work investigates two complex, heterogeneous sandstone lithofacies in a north sea petroleum reservoir field. The sedimentation of the north sea reservoir rocks, norwegian petroleum society npf, geilo 1980, p. He has experience in the north sea, the middle east, china, indonesia, chile, ecuador, peru and colombia, as well as the us rocky mts. Mar, 2018 the north sea including the danish central graben is a mature oil province where the primary source rock is composed of upper jurassic lowermost cretaceous marine shales. The chemical composition of feldspar grains in samples from. Facies characterization of a reservoir in the north sea. Geological history of the north sea basin introduction the north sea basin covers and area of 625,000 km2 and is lies north of the netherlands and in between norway and great britain. Pdf the geotechnical characteristics of weak north sea reservoir rocks.
The tiffany and toni oil fields, upper jurassic submarine. The storage capacities of the southern north sea gas fields were calculated in the gestco study. Abstract this study presents source and reservoir characterization of jurassic rocks by conducting compaction study, petrophysical analysis and rock physics diagnostics on data from 18 exploration wells in the central north sea, focusing on the ling depression and adjacent areas. These source rocks are of various types and differ in their potential for forming hydrocarbons. Peristeritic plagioclase in north sea hydrocarbon reservoir. Interpretion of the fault system in a hydrocarbon source rock. A reservoir classification and rock typing study were carried out on the upper rudeis reservoir rocks asl and hawara formations, of a mixed siliciclastic and carbonate lithology in the gulf of suez, egypt, by integrating both largescale geologic elements and smallscale rock petrology with the physical rock properties for the studied reservoir. Pdf reservoir quality and rock properties modelling triassic. Fossils range from the very small single cell to the larger shelled animals.
The zechstein sea occupied the region of what is now the north sea, plus lowland areas of britain and the north european plain through germany and poland. Since the 3rd edition of this publication, emphasis within the petroleum industry has shifted from exploration to appraisal and development of existing hydrocarbon resources. Berthierine formation in reservoir rocks from the siri oilfield danish north sea as result of fluidrock interactions. Reservoir sandstones from well 30167 in the upper jurassic humber group, uk north sea, contain plagioclase feldspars with a range of chemical compositions, microtextures, and origins. The north sea basin is located in northern europe and lies between the united kingdom, and norway just north of the netherlands and can be divided into many subbasins. The first north sea oil and gas reservoirs conference was held in trondheim in. The programme investigated both microbiological biogenic and nonmicrobiological souring mechanisms and was completed three years later, culminating in public presentation 1. The southern north sea basin is the largest gas producing basin in the uk continental shelf, with production coming from the lower permian sandstones which are sealed by the upper zechstein salt. Reservoir rocks around the world is dominated by sedimentary rocks because generally it has primary porosity. Petroleum prospectivity of the principal sedimentary basins. The elements of the petroleum system charge, trap, and reservoir, are described systematically within the framework of play and prospect.
A competent, granular sandstone typically has a c pv value of about 5 x 104mpa 3 x 106psi, but it can exceed 15 x 104mpa 100 x 106psi for highly compressible north sea chalks below. Characterization of reservoir rock types in the upper rudeis. In most of the north sea graben, source rocks have been continuously buried since deposition. Evidence is drawn from integrated analysis of over 50,000 line kilometres of seismic data and well data, together with regional source rock screening, reservoir analysis and. The use of permanent or semipermanent sea bottom acoustic sensors for reservoir seismic and reservoir surveillance k. The geotechnical characteristics of weak north sea. Refined reservoir interpretation with the aid of high resolution seismic data and seismic attribute mapping m. It is a good reservoir in such fields as celiklu, garzan, germik, kurtalan, magrip, magrip north, gyuktas, raman west, sezgin and silivanka fig. Synrift reservoirs are restricted to strata actually deposited during maximum extension and include rocks of late jurassic to earliest cretaceous age. Accordingly, knowledge of in situ stress and how stress changes with reservoir depletion is important in a multidisciplinary approach to reservoir characterization, reservoir management, and enhanced oil recovery projects. Geological background this study used sandstone reservoir rocks from the fulmar oilfield, which is located in the southwestern part of the cen. Microseismic monitoring of reservoir rock and cap rock. The compressibility of reservoir rock is a factor which is generallyneglected in reservoir engineering calculations.
The ekofisk field in the norwegian sector of the north sea, with reserves in excess of 1. Geological survey of northern ireland, colby house. Bjoroy 2 1 fossil fuels and environmental geochemistry, drummond building, university of newcastle, newcastle upon tyne, ne1 7ru, uk. Geological history of the north sea basin petroleum geology. Palaeozoic petroleum systems of the central north seamid north. The beryl a platform was emplaced in 1975 and the beryl b platform in 1983. In the case of conventional type, the rock consists of grains bound together by a bunch of material such silica, calcite, and clay. The existence of an extensive, prospective viseannamurian carboniferous petroleum system in and around the hitherto underexplored mid north sea high is documented. Reservoir parameters estimation from well log and core. The reservoir geochemistry of the eldfisk field, norwegian. Southern north sea tight gas oil and gas authority. South brae field was discovered in 1977, its oil being found deeper down than in most north sea fields, within a maximum of thickness of over 500 metres of reservoir rock. The skarfjell discovery is an example of a combined structuralstratigraphic trap.
Petroleum geology of the gorm field, danish north sea. Omission of rock compressibility is undoubtedlyjustified in calculations for. The reservoir lies at depths in excess of 11800 ft tvss, has a maximum gross hydrocarbon column of 1670 ft, and covers an area of approximately 6000 acres. The tiffany and toni fields lie at the western margin of the south viking graben in the northern north sea in uk block 1617. This means that mature kimmeridge clay source rock intervals in the hanging wall can be found adjacent to devonian, carboniferous and permian reservoir rocks in the footwall, allowing oil sourced from deep in the central graben to migrate into reservoirs in the mid north sea high region. Over the last ten years there have been a number of computer modelling studies of the field which have all assumed an original oil. The silverpit crater, a 20 kilometers 12 mi diameter suspected impact crater in the north sea 6065 ma. A summary of the variability in source rock properties by geographical area is given in sections 4. For fluids to enter the pore space, pressure is necessary. This is due in part to thefact that there is little published information on rock compressibility valuesfor limestones and sandstones. Some will mainly generate gas, while others are more likely to form oil. Data from the core samples studied are taken from depths varying from 2. Pdf berthierine formation in reservoir rocks from the.
It is unlikely that the vast quantities of oil and natural gas now present in some reservoir rocks could have been. Rockphysics modeling of stress sensitivity and 4d time. The trap formed along the northern edge of a deep wnwesetrending submarine canyon. Reservoir rocks are totally classified as conventional and unconventional rocks. The reservoir is the upper jurassic brae formation which is downfaulted against tight sealing rocks of probable devonian age at the western margin of the field. Petroleum geology of the north sea wiley online books. North sea basinal area, europe an important oil and gas province.
It occupies the shallow northern portion of the caspian sea and a large plain to the north of the sea between the volga and ural rivers and farther east to the mugodzhary highland, which is the southern continuation of the ural foldbelt. Shortly after burial chalk in general has a high porosity, but a low permeability. Porosity and hydrocarbon distribution in the north sea chalk reservoirs. Mapping lithofacies and porefluid probabilities in a north. Other detrimental aspects of reservoir compaction well casing collapse and surface subsidence may also occur. Development geology training course petroskills dg. This thesis entitled 3d seismic stratigraphy and reservoir characterization of the chalk group in the norwegian central graben, north sea has been submitted for the degree of philosophiae doctor phd at the university of bergen uib, norway. Rotliegendes formation, the upper permian dolomites of the zechstein forma.
Over the last ten years there have been a number of computer modelling studies of the field which have all assumed an original oil in place of approximately 2000 mmstb 318. The location and boundaries of the north sea graben province are shown in figure 1. The assessment of petroleum resources of the north sea, as well as other areas of the world, requires a viable means to forecast the amount of growth of reserve estimates reserve growth for discovered fields and to predict the potential fully developed sizes of undiscovered fields. In contrast to the adjacent gasprone anglodutch and northwest german basin provinces, the north sea graben. The gorm field is located within the central graben of the north sea. Reserve growth in oil fields of the north sea petroleum.
The evaporite rocks of the zechstein formation were laid down by the zechstein sea, an epicontinental or epeiric sea that existed in the guadalupian and lopingian epochs of the permian period. The southern north sea basin area, stretching from the uk to the. Here, therefore, the reservoir rock is the same age as the source rock. The increasing number of effective properties that may. In this study a combined approach of petrophysical analysis, compaction study and rock physics diagnostic is used to understand reservoir properties and its variation with respect to burial diagenesis. Petroleum geology and resources of the north caspian basin. Seismically obscured areas shallow gas causes attenuation of seismic response at the chalk horizons common in north sea chalk oil fields uncertainty for building the geological model and thus inplace volumes and planning well locations compaction and subsidence in chalk once production starts high porosity and relatively weak rock.
Reservoir characterization of triassic and jurassic. This course addresses the fundamentals of petroleum systems analysis, a holistic view of how it works, which is essential for geoscientists and engineers involved in todays challenging conventional and unconventional exploration and development projects. We carried out triaxial tests on samples of potential north sea reservoir rocks sandstones of sognefjord and utsira formations and cap rock shale of draupne formation. Petroleum systems in the barents sea comprise a number of possible source rocks figure ohm et al, 2008. The valhall field in the norwegian north sea is a high porosity chalk reservoir undergoing primary pressure depletion. Petroleum prospectivity of the principal sedimentary. Small displacements in faults may originate compartmentalization of a reservoir, seminal factor to be consider in order to optimise a field development.