Knut Bjørlykke

Knut Bjørlykke
University of Oslo · Department of Geosciences

PhD

About

202
Publications
121,684
Reads
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9,788
Citations
Citations since 2017
4 Research Items
4445 Citations
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Additional affiliations
July 1984 - present
University of Oslo
Position
  • Professor (Full)
September 1976 - June 1984
University of Bergen
Position
  • Professor og Petroleum Geology
August 1976 - July 1984
University of Bergen
Position
  • Professor (Full) of Petroleum Geology
Description
  • Head of petroleum Geology. Also head of Department in periods

Publications

Publications (202)
Book
Petroleum Geology, Sedimentology, Stratigraphy diagenesis, Seismics, geophysics , well logging With contributions from Per Avseth, Jan Inge Faleide, Pa°l T. Gabrielsen, Roy H. Gabrielsen, Nils-Martin Hanken, Helge Hellevang, Kaare Høeg, Jens Jahren, Sta°le Emil Johansen, Ragnar Knarud, Martin Landrø, Nazmul Haque Mondol, Jenø Nagy, Jesper Kresten N...
Article
This study investigates petrophysical and acoustic properties of experimentally compacted reconstituted samples of seal sequences from the southwestern Barents Sea. The aggregates were collected from drill cuttings of mudstone and shale formations of two exploration wells, 7220/10-1 (Salina discovery) and 7122/7-3 (Goliat field). The washed and fre...
Article
Full-text available
The Lower Cretaceous Quantou Formation in the southern Songliao Basin is the typical tight oil sandstone in China. For effective exploration, appraisal and production from such a tight oil sandstone, the diagenesis and reservoir quality must be thoroughly studied first. The tight oil sandstone has been examined by a variety of methods, including co...
Research
The tight sandstones of the Cretaceous Quantou formation are the main exploration target for hydrocarbons in the southern Songliao basin. Authigenic quartz is a significant cementing material in these sandstones, significantly reducing porosity and permeability. For efficient predicting and extrapolating the petrophysical properties within these ti...
Article
Stratigraphy is the study of the succession and time related architecture of rock strata. Stratification is not limited to sedimentary rocks, but is also found in igneous rocks, particularly volcanic rocks, and in certain plutonic rocks. All bedded rocks can be treated stratigraphy, i.e. establish age relations between beds. However, the term “stra...
Chapter
Sedimentology is the study of sedimentary rocks and their formation. The subject covers processes which produce sediments, such as weathering and erosion, transport and deposition by water or air, and also the changes which take place in sediments after their deposition (diagenesis). Diagenesis includes mechanical sediment compaction as a and miner...
Article
The composition and physical properties of sedimentary rocks are to a large extent controlled by chemical processes during weathering, transport and also during burial (diagenesis). We can not avoid studying chemical processes if we want to understand the physical properties of sedimentary rocks. Sediment transport and distribution of sedimentary f...
Book
This comprehensive textbook presents an overview of petroleum geoscience for geologists active in the petroleum industry, while also offering a useful guide for students interested in environmental geology, engineering geology and other aspects of sedimentary geology. In this second edition, new chapters have been added and others expanded, coverin...
Article
Sedimentology, sequence stratigraphy and facies analysis have for many years been disciplines rather separate from diagenesis which is concerned with processes occurring after deposition. Prediction of rock properties as a function of burial depth in sedimentary basins requires that these disciplines become more integrated. Compaction of sedimentar...
Article
Descriptions of mineralogy and textural relationships in sandstones and limestones have been used to establish a sequence of diagenetic events (epigenesis), involving mineral dissolution and precipitation, which have been interpreted to have occurred during the burial history. Published epigenetic sequences commonly imply a geochemically open syste...
Article
Full-text available
Many authors have proposed that significant volumes of porosity are created by deep-burial dissolution in carbonate reservoirs. We argue, however, that this model is unsupported by empirical data and violates important chemical constraints on mass trans-port. Because of the ubiquitous presence and rapid kinetics of dissolution of carbonate minerals...
Article
Layered low permeability rock units, like shales, represent seals or ‘cap-rocks’ in a variety of geological settings. A continuous increase in the fluid pressure gradients across a virtually impermeable rock layer will ultimately lead to hydro-fracturing. Depending on the boundary conditions, such fracturing may lead to the formation of a set of su...
Article
Full-text available
The deeply buried synrift play of the South Viking Graben is characterized by highly variable reservoir quality. An integrated approach incorporating petrophysics, petrography, and one-dimensional basin modeling methods was applied to investigate these variations. Analysis shows that average porosities below 4000 m (> 13,123 ft) (vertical depth bel...
Conference Paper
Full-text available
This study investigates permeability anisotropy in well characterized synthetic mudstones. A total of 10 brine-saturated synthetic mudstones of varying textural and mineralogical compositions were compacted in a triaxial cell (K0-consolidation) while the vertical and horizontal permeability were measured at different stress levels. The results show...
Conference Paper
Full-text available
Many authors have proposed that late burial dissolution has created significant volumes of porosity in carbonate reservoirs. We argue, however: (1) that this model is almost entirely unconstrained by quantitative evidence, (2) that mass-balance constraints indicate that the proposed causes of mesogenetic carbonate dissolution are vastly insufficien...
Article
This study presents the results of experimental compaction while measuring ultrasonic velocities of sands with different grain size, shape, sorting and mineralogy. Uniaxial mechanical compaction tests up to a maximum of 50 MPa effective stress were performed on 29 dry sand aggregates derived from eight different sands to measure the rock properties...
Article
Full-text available
This study examines the one-dimensional stress–strain behaviour of sand at effective stresses as high as 50 MPa. Experiments were performed on 22 sands (approx. 150 tests) with different grain size, uniformity coefficient, angularity, density, grain mineralogy, and clay content. The results show that minor grain corner crushing starts at stresses o...
Article
Uniaxial compression tests were conducted on bioclastic sand and crushed calcite crystals. Mechanical and chemical processes were investigated to better quantify petrophysical properties of carbonates and their evolution with burial or during fault zone processes. The grain size was in the range 63–500 μm, and the samples were saturated with water...
Article
This study describes uniaxial mechanical compaction tests performed on two naturally occurring unconsolidated sands with different mineralogy, quartz-rich and quartz-poor, in order to investigate the effect of pore pressure on the P-wave velocity. The compaction experiments simulated burial of sands with increasing vertical stress and pore pressure...
Chapter
Full-text available
Of all the geophysical exploration methods, seismic surveying is unequivocally the most important, primarily because it is capable of detecting large-scale to small-scale subsurface features. Simply stated, seismic methods involve estimation of the shapes and physical properties of Earth’s subsurface layers from the returns of sound waves that are...
Chapter
Full-text available
The term 4D seismic reflects that calendar time represents the fourth dimension. A more precise term is repeated seismic, because that is actually what is done: a seismic survey over a given area (oil/gas field) is repeated in order to monitor production changes. Time-lapse seismic is another term used for this. For some reason, the term 4D seismic...
Chapter
For many decades conventional oil which could be produced at low cost was present in abundance. A low oil price gave no incentive to look for other types of resources. It is now clear, however, that we are gradually running out of new sedimentary basins to explore and that the reserves of conventional oil which can be produced cheaply are limited.
Chapter
In the preceding chapters we have included only a few regional examples and case studies because of space limitations. The present chapter will, however, provide some examples. The North Sea and other parts of the Norwegian continental shelf contain several different petroleum provinces which can illustrate some of the general principles of petrole...
Chapter
About 50% of all petroleum reservoirs are sandstones; outside the Middle East, carbonate reservoirs are less common and the percentage is even higher. The most important reservoir properties are porosity and permeability, but pore geometry and wetting properties of the mineral surfaces may also influence petroleum production. Sandstones provide res...
Chapter
The transport of petroleum from the source rock to the reservoir rocks is called migration. It is important to understand this process so that the direction of migration and trapping of petroleum can be predicted. Many different theories have been proposed in the past but it is now clear that petroleum is mainly transported as a separated phase and...
Chapter
Seismic records are based on measurements of the time sound waves (seismic waves) take to travel through rock. The sound or signal is produced by explosives or compressed air (air guns). Rock is an elastic medium and the velocity of sound conveys a lot of information about the properties of the rock. Normal sound waves (P-waves) travel through both...
Chapter
The temperature increases downwards in the crust and there is therefore a transport of heat upwards, referred to as the heat flow. Most of the flow is by conduction (thermal diffusion). Flow of porewater will also transport heat in the subsurface but the flow rates in sedimentary basins are normally so small that we can ignore the contribution from...
Chapter
As discussed in Chap. 1, petroleum is generated from organic matter which accumulates in sedimentary basins. Only a small fraction of the organic matter produced in the photic zone in the ocean becomes trapped in sediments (Fig. 14.1). Most of the organic matter is oxidised in the water column or on the seafloor and the nutrients are released into...
Chapter
Petroleum geology comprises those geological disciplines which are of greatest significance for the finding and recovery of oil and gas. Since most of the obvious and “easy to find” petroleum already has been discovered it is necessary to use sophisticated methods in the exploration of sedimentary basins. These include advanced geophysical techniqu...
Chapter
Logging is a way of recording the physical properties of the rocks penetrated by a well. Logging started with simple electric logs measuring the electrical conductivity of rocks, but it is now a technically advanced and sophisticated method. Here only the basic principles will be introduced but there are several specialised textbooks on well loggin...
Chapter
Full-text available
The field of rock physics represents the link between qualitative geological parameters and quantitative geophysical measurements. Increasingly over the last decade, rock physics has become an integral part of quantitative seismic interpretation and stands out as a key technology in petroleum geophysics. Ultimately, the application of rock physics...
Chapter
The concept of plate tectonics offers a useful framework for structural geological analysis on all relevant scales in petroleum geology, from regional in the exploration stage, to local in the reservoir evaluation and production stages. This is natural, because the principal geological stress systems are ruled by processes in the deep earth like ma...
Chapter
Full-text available
The composition and physical properties of sedimentary rocks are to a large extent controlled by chemical processes during weathering, transport and also during burial (diagenesis). We can not avoid studying chemical processes if we want to understand the physical properties of sedimentary rocks. Sediment transport and distribution of sedimentary f...
Article
Overpressure generation is a function of the rates of sedimentation, compaction, fluid generation from kerogen and dehydration of minerals, and most importantly the lateral distribution of permeability within a basin as this controls lateral drainage. Sedimentary basins, however, are typically highly heterogeneous with respect to primary sedimentar...
Article
This study is based on rock mechanical tests of samples from platform carbonate strata to document their petrophysical properties and determine their potential for porosity loss by mechanical compaction. Sixteen core-plug samples, including eleven limestones and five dolostones, from Miocene carbonate platforms on the Marion Plateau, offshore north...
Article
For the first time, nanometer resolution techniques both in situ and ex situ were compared in order to study calcite dissolution under stress. The obtained results enabled identification of the relative importance of pressure solution driven by normal load and free surface dissolution driven by strain energy. It is found that pressure solution of c...
Article
Late Cretaceous mudstones from two wells located in the northern North Sea and the Norwegian Sea have been examined with respect to quartz cement. Two different types of quartz cement (Type 1 and Type 2) have been identified using SEM/EDS/CL-analysis of drill-bit cuttings at depths 2370–2670 m (80–85 °C). Type 1 appears as relatively large aggregat...
Article
Rock physical properties, like velocity and bulk density, change as a response to compaction processes in sedimentary basins. In this study it is shown that the velocity and density in a well defined lithology, the shallow marine Etive Formation from the northern North Sea increase with depth as a function of mechanical compaction and quartz cement...
Article
Oedometric mechanical compaction tests were performed on brine-saturated synthetic samples consisting of silt-clay mixtures to study changes in microfabric and rock properties as a function of effective stress. The silt consisted of crushed quartz (∼100%) with grain size range between 4 and 40μm, whereas the clay consisted of 81% kaolinite, 14% mic...
Article
Mudstones and shales are a major component of most sedimentary basins and are anisotropic because of the alignment of plate-line clay minerals. The results show that the shallow mudstone is weakly anisotropic with respect to P-wave anisotropy (Thomsen s parameter s) on the order of 20% but strongly anisotropic for S-wave propagation (Thomsen s para...
Chapter
Full-text available
At shallow depths in sedimentary basins there are soft clays and loose silts and sands, while diagenetic processes have transformed these sediments to claystones, shales, silt- and sandstones at greater depths. Sedimentary rocks continuously undergo physical and chemical changes as a function of burial depth, temperature and time, and important hyd...
Article
The physical properties of sedimentary rocks change continuously during burial as a response to increasing stress and temperature; they also change to a certain extent during uplift and cooling. There is an overall drive towards lower porosity with depth, which increases the density and velocity.
Article
Sedimentology is the study of sedimentary rocks and their formation. The subject covers processes which produce sediments, such as weathering and erosion, transport and deposition by water or air, and also the changes which take place in sediments after their deposition (diagenesis). Changes in sedimentary rocks at temperatures of over 200-250°C ar...
Article
Full-text available
Compaction of sediments is driven towards lower porosities and higher densities as a function of increasing stress and chemical reactions. Mechanical processes are controlled by the effective stress and chemical compaction by dissolution and precipitation of solids. Chemical compaction is a function of thermodynamics and kinetics and silicate react...
Article
Basin modelling studies are carried out in order to understand the basin evolution and palaeotemperature history of sedimentary basins. The results of basin modelling are sensitive to changes in the physical properties of the rocks in the sedimentary sequences. The rate of basin subsidence depends, to a large extent, on the density of the sedimenta...
Conference Paper
Full-text available
This study investigates the implications of clay minerals and grain size for Vs estimations in mudrocks. A series of experimental compaction test of well characterized synthetic mudstones helps to understand the velocity development in mudrocks as a funct
Article
The Late Cretaceous to Early Tertiary sequence of the Vøring and Møre Basins from the Norwegian Sea has been examined with respect to mineralogy based on 319 cutting samples from five wells. A clear relationship between mineralogy and well log data is demonstrated. A significant change with respect to velocity, porosity and density occurs within th...
Chapter
Full-text available
The volume of precipitated quartz cement and the resulting porosity loss in a quartzose sandstone can be calculated from the temperature history of the sandstone based on an equation relating the quartz precipitation rate per unit surface area and per unit time to temperature. In addition to temperature and time, the quartz surface area available f...
Article
For the first time, direct petrographic evidence of fine-grained (1–3 μm) crystals of pore-filling quartz cement in mudstones is documented. The cathodoluminescence responses of the micro-quartz give a clear indication of an authigenic origin. The detection of micro-quartz cement in drill-bit cutting samples at depths around and deeper than 2500 m...
Article
Full-text available
The anisotropy of physical properties is a well-known charac-teristic of many clay-bearing rocks. This anisotropy has impor-tant implications for elastic properties of rocks and must be con-sidered in seismic prospecting. Preferred orientation of clay min-erals is an important factor causing anisotropy in clay-bearing rocks such as shales and mudst...
Article
Vertical and lateral changes in physical properties in Cenozoic mudstones from the northern North Sea Basin reflect differences in the primary mineralogical composition and burial history, which provides information about sedimentary facies and provenance. Integration of well-log data with mineralogical information shows the effect of varying clay...
Article
We have compared compaction trends for synthetic mudstones to well logs in order to predict pore pressure in shallow mudstone sequences in the northern North Sea and Vøting Basin, offshore Norway. Well log data showing intervals of higher porosity and lower density than the experimental data may indicate significant overpressure development. The va...
Article
Full-text available
This study determines the relationship between permeability and other petrophysical properties in synthetic mudstones as a function of vertical effective stress. Six brine-saturated clay slurries consisting of smectite and kaolinite were compacted in the laboratory under both controlled pore pressure and proper drained conditions. Porosity, permeab...
Conference Paper
This study investigates the effects of grain size on petrophysical and acoustic properties of experimentally compacted synthetic mudstones. Four brine-saturated kaolinite aggregates sorted by the grain size were compacted in the laboratory under vertical effective stress up to 50 MPa. Results show that the kaolinite aggregates compacted differently...
Article
Clay minerals are the most abundant materials in sedimentary basins. The most common - like kaolinite, illite, chlorite, and smectite - are found in various amounts in mudstones and are also often found in clastic and nonclastic reservoir rocks. Their presence alters the elastic behavior of reservoir rocks significantly as a function of mineral typ...
Article
The Late Cretaceous to Early Tertiary sediments of the Voting and More basins are predominantly composed of fine-grained mudstones. Variations in the mineralogy and chemistry of these mudstones provide information regarding facies, provenance and burial history, and may also be used to predict rock properties. Over 300 cuttings' samples from five w...
Article
Full-text available
Shales and mudstones composed of clay minerals and quartz are important sedimentary rocks that frequently display anisotropy of physical properties. This study investigates anisotropy in experimentally compressed kaolinite-illite-quartz aggregates by determining preferred orientation (texture) of component phases and comparing results with acoustic...
Article
Open fractures provide high-permeability pathways for fluid flow in sedimentary basins. The potential for flow along permeable or open fractures and faults depends on the continuity of flow all the way to the surface except in the case of convective flow. Upward flowing fluid cools and may cause cementation due to the prograde solubility of quartz,...
Article
When sands are buried in sedimentary basins the additional overburden mechanically compact the sands to a denser configuration. Burial also increases temperature and the porosity is reduced by chemical compaction. Therefore, the geomechanical behavior of sandstones is to a large extent controlled by mechanical and chemical compaction. To investigat...
Conference Paper
Full-text available
Experimental and natural compaction of sands, carbonates and clays: Consequences for stress and fluid flow 1. Abstract Mudstones are very heterogeneous with respect to grain size, mineralogical composition and their physical and chemical properties vary within wide ranges. Mudstones may contain significant amount of silt and sand sized clastic grai...
Article
Dry and brine-saturated clay aggregates ranging from pure smectite to pure kaolinite were compacted in the laboratory. Experiments were conducted by increasing vertical effective stress up to 50 MPa to study the changes in physical properties of mudstones during burial. The results suggest that the physical properties (porosity, density, acoustic v...
Article
Full-text available
Based on logs from 60 wells located on the Norwegian Shelf, we concluded that compaction and velocity trends vary greatly with depth in different types of mudstones and shales (Storvoll et al., 2005). Japsen (2006), however, argues that compaction of shales can be represented by a linear velocity-depth trend as a function of the overburden stress a...
Article
Modelling of sediment compaction requires that the rate limiting processes are understood. The compaction of uncemented sediments at relatively shallow burial depths should be modelled as a function of effective stress following soil mechanical principles and using experimental compaction data for calibration. In siliceous rocks chemical compaction...
Article
Significant overpressures are either controlled mechanically by the fracture pressure or by the matrix permeability if there is no leakage on fractures. In a recent publication in this journal Nysæther (2006) attempts to explain the degree of overpressure in reservoirs from Haltenbanken based on a pressure cell model. The paper contains interesting...
Article
Faults may be barriers or conduits for fluid flow in sedimentary basins. The properties of faults, however, depend on stress conditions and rock properties at the time of deformation and subsequent diagenesis of the fault zone. Several recent publications have suggested that petroleum reservoirs in the North Sea and at Haltenbanken, offshore mid-No...
Article
Full-text available
Sonic velocity, density, and resistivity log data from 60 wells on the Norwegian Shelf have been used to investigate velocity-depth trends in sedimentary rocks as a function of sediment composition, porosity, pore-pressure, burial-history, and compaction processes. A first-order linear velocity-depth trend line has been estimated from published vel...
Article
The reduction in porosity due to mechanical compaction and chemical processes are principally different processes and must be modelled separately even if they overlap in time. Experimental compaction of loose sand show that stresses exceeding 20-30 MPa cause significant grain crushing particularly in coarse-grained sand. Evidences of such grain fra...
Article
The paper presents the results of laboratory compaction tests on two samples of the lower Kimmeridge Clay Formation obtained from two different outcrop localities in the UK. The purpose of the testing programme is to study the compaction behaviour of an argillaceous sediment from the same parent material but with different diagenetic histories. Sin...
Article
The purpose of this study was to examine the effect of grain contacts and quartz cementation with regard to acoustic wave propagation in sandstones. Grain contacts have been considered essential when relating acoustic velocities to physical rock properties, and a parameter numerically representing the contact area between individual grains (contact...
Article
The evolution of the petroleum systems in the Tampen Spur area, with main focus on the filling directions of the northern part of Snorre field, was addressed through 2D basin modelling (Petromod V. 4.5 and 7.0). The geochemical classification of the petroleum populations in the area represented the framework for considering the different kitchen ar...
Article
Full-text available
Petroleum inclusion and geochemical data from core extracts were applied to deduce a model for oil migration, overpressure development and palaeo-leakage of oil from currently dry structures in the Haltenbanken Vest area. The existence of fluorescent oil type inclusions in quartz in the Smørbukk (Åsgard-2) field suggest that oil migrated into this...