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The thesis is devoted to calibration of a process-based numerical model and its application to simulation of the Late Quaternary history and stratigraphy of the Northern Adriatic Sea. Tests aimed at assessing the sensitivity of the model to initial and boundary conditions were conducted, based on geomorphologic and stratigraphic data culled from literature. Based on these tests, wave-generated erosion and diffusion coupled with current-induced removal and transportation algorithms were adopted to simulate intensification of the Western Adriatic Coastal Current (WACC) by the Bora Wind during the Late Holocene. Different scenarios have been assessed to examine the model’s ability to reproduce the stratigraphic architecture of the Adriatic Basin. Model results for the prodelta of the Po River at the north-western low-gradient shelf are represented by a continuous subaqueous delta, which forms an elongated coast-hugging deposit. The central Apennine part of the western shelf, which has a comparatively steep gradient, is characterized by the presence of fluvio-deltaic lobes deposited by the Apennine Rivers. The sediment budget has been calculated based on the isopach maps of modelled stratigraphy. A total sediment mass of abut 800 Gt was supplied to the basin over the time span corresponding to TST and HST (~19 kyr). Volumetric estimates indicate that roughly 87% of the supplied sediments have been preserved on the shelf. This suggests an export of ~13% to the MAD and to the southern part of the basin. The result is compatible with literature, where 10% of the sediment has been reported to move south of the Gargano promontory. Over the past 5.5 kyr, 256 Gt of sediment has been preserved on the shelf and is stored in the HST, corresponding to an average rate of deposition about 46 Mt yr-1, which is ~4 Mt yr-1 more than study reports. The rate of fluvial sediment supply (52 Mt yr-1) during formation of the HST suggests an export of ~6 Mt yr-1 to deeper parts of the basin below the effective hydrodynamic base.

An underground CO2 storage project is proposed under the village of Barendrecht, involving two nearly depleted gasfields. Because of the lack of sufficient knowledge of these kinds of storage projects, by the general public and also by the local politicians, several questions about the technical and geological aspects have been raised. In this report an effort is made to answer specific questions about the subsurface and its reaction to a CO2 storage project in a clear manner. These answers lead the reader through general CO2 information, followed by site specific details and also new calculations on the possibility and rate of CO2, that might escape from the reservoir in case of a dramatic subsurface failure. Based on our findings, as well as on previous research, we conclude that the threat of an accident is almost non-existent.

Peat is sediment consisting of incompletely decomposed organic matter deposited in swamp and marsh. It has served for a long time as benefits for human beings. Meanwhile, it has posed huge challenges to geotechnical engineers because of its unique characteristics such as anisotropy, low stiffness, high compressibility and strong creep susceptibility. In order to realise more effective and efficient site investigations, it is highly expected to apply geophysical techniques as well as core-boring, CPTs, sampling and laboratory tests because the techniques promise to be great contributions not only for two- or three-dimensional mapping but also for accurate interpretation of its physical, chemical and engineering properties in non-destructive way. Then, a new apparatus has been developed, called hybrid Rowe cell. It combines the functions of a traditional hydraulic cell and an electrical capacitor. This can simultaneously measure electrical properties and physical, mechanical and hydrological properties of soil samples, allowing to investigate their correlation accurately. This work focuses on the study of the applicability and calibration of the new hybrid cell, and the relationship between electrical conductivities of bulk peat and pore water which saturates the sample. The applicability of the hybrid cell was examined by using water as calibration. The results were then compared with values reported earlier and the experimental set-up was also compared with similar one found in literature. As a result, it was proven that the new cell successfully prevented electrode polarization and was applicable for this type of measurements. The electrical measurements on peat showed a relationship between the electrical conductivities of bulk peat and pore water which could be well predicted by a model previously developed for peat as well as the modified Archie’s law. In addition, the modified Archie’s law could be considered to be a persuasive model for the electrical behaviours observed in this study. For the future research, it is highly expected that the frequency of input currents is extended to lower range (< 20 Hz), input electric currents are properly controlled to avoid non-linear effects, and also hydraulic consolidation tests are performed in parallel with electrical measurements.

A promising possibility to reduce corrosion resistant pipeline costs is the concept of Tight Fit Pipe, which is a double wall pipe where a Corrosion Resistant Alloy liner is mechanically fitted inside a carbon steel outer pipe. The mechanical bonding of the Tight Fit Pipe is made through a thermohydraulic manufacturing process. Problem definition Buckling of cylinders subjected to flexural loads (applied to Tight Fit Pipe during cost effective reeling) correlates in a number of respects to buckling of axially compressed cylinders: in both cases the critical stresses (or strains) are of the same order of magnitude and the failure modes have the same characteristics. Results from the axial compression tests provided better understanding of the buckling behaviour of Tight Fit Pipe during bending and results from this thesis study have been used as input for a bending rig construction. Research The main objective of this thesis is to investigate, theoretically and experimentally, the local buckling behaviour due to axial compression of the Corrosion Resistant Alloy liner, whilst fitted in the outer pipe of the Tight Fit Pipe configuration. The liner of the Tight Fit Pipe as tested is first analysed when not fitted in the outer pipe. Secondly the liner is analysed when fitted in the outer pipe of the Tight Fit Pipe. The liner has a higher capacity in stress and strain when the liner is placed in the outer pipe, i.e. mechanically fitted, compared with the liner alone. Results, Conclusions and Recommendations [a.] Buckling of the liners (of Tight Fit pipes (TFP) used in the experiments), without the outer pipe, occurred outward in a single axi symmetrical wrinkle. [b.] The liners in the tight fit pipes, confined in an outer 12 ¾ inch pipes used in the experiments, buckle inward in a non-symmetrical wrinkle. [c.] Wrinkles (of liners confined in an outer 12 ¾ inch pipe) do not exceed 90º of the circumference. The wrinkles have an axis which is circumferential. Wrinkles do not tend to connect with each other if more than one is present at about the same height. [d.] The maximum force in the load - strain diagram was considered to be the point at which wrinkling occurred. There was a good agreement between the Finite Element (FEM) results and test results for the maximum force. The FEM results for the strain at the maximum force were much higher than in the tests. [e.] Buckling of a liner in a 12 ¾ inch pipe has a larger critical buckling force than a liner which is not confined in an outer pipe. This is due to the resistance to outward buckling. Bigger wrinkles must fit in a smaller radius which costs more energy than free outward buckling. This could also be the reason why the wrinkles do not tend to form as one big wrinkle in a 360 degrees radius. Outward buckling tend to occur in one axi symmetrical wrinkle. [f.] The buckling behaviour of the liner in the TFP is believed to be influenced by three different TFP properties: [f1.] Low or high fit (residual hoop stress), [f2.] Type of CRA (Material strength) and [f3.] Type of outer pipe used, seamless or UOE-pipe (Liner to outer pipe contact irregularities ) [f1] has been proven in the test results; [f2] and [f3] are still to be proven in future work.

Seafloor Massive Sulfide (SMS) contains high levels of metals such as copper and gold. Water depths of 2000 up to 3000 meter make mining of SMS a challenge. Despite this, mining industry encourages research into feasible extraction methods of SMS, pushed by the high metal prices nowadays. This research focuses on the influence of hydrostatic pressure on the cutting process of hard rock. A 2D numerical model of the cutting process is created using discrete element modelling (DEM). The software package Particle Flow Code 2D (PFC2D) from Itasca Consulting Group is used. The rock material creation in PFC2D consists of reproducing numerically the physical UCS, biaxial and Brazilian tests executed on the benchmark material. SMS is the rock of interest for deep-sea mining, nevertheless Langmeil Sandstone is chosen as benchmark material. This consideration is taken because SMS samples are rare and no strength test results obtained on SMS samples are published. In addition the high heterogeneity of SMS makes their numerical modelling difficult. It was not possible to come up with a singular numerical rock sample matching the mechanical properties of the Sandstone for a large range of confining pressures (0 to 40 MPa). Therefore two samples were created: the first sample is valid for unconfined tests, the second sample is valid for confining pressures between 20 and 40 MPa. It appeared that the material unconfined compressive strength and elastic constants are independent of the particle size. The transition point from brittle to ductile failure is simulated successfully for the second rock sample. Three different cutting scenarios are studied: cutting of dry rock without hydrostatic pressure, cutting of dry rock under hydrostatic pressure and cutting of saturated rock. The boundary particle method is an algorithm capable of simulating hydrostatic pressure. This method applies a force similar to the hydrostatic load on each boundary particle of the sample. The method simulates the transition between brittle and ductile rock cutting successfully, by increasing the effective stress, while fluid and pore pressures are absent. The transition from brittle to ductile cutting is reached at a hydrostatic load of 20 MPa for the Langmeil sandstone. The cutting force (450 kN) obtained by the numerical model for the unconfined calibrated rock is compared with existing semi-empirical models. Goktan’s (1995) model (300 kN) provides the best match , Evans’ (1961) model (75 kN) underestimates the required cutting force. The horizontal cutting force increases with increasing hydrostatic pressure. The increase of hydrostatic load is mainly transferred into an extra load on the cutting tool in horizontal direction. The specific energy calculated from the cutting force obtained by the numerical model (4.9 MJ/m3) is in good accordance to the values for sandstone found in literature (5.5 MJ/m3). The influence of the tool shape, the cutting velocity and depth of cut on the cutting process of dry rock is modelled. The chisel pick tool shows to be more efficient than the pick point tool for shallow water depths. The difference in efficiency between these tools becomes smaller with increasing hydrostatic pressures. Measurement circles in PFC2D are able to register porosity changes during the cutting process. These measurements are used to estimate pressure differences in the crushed zone. This method provides a good qualitative insight in the development of pore pressures during the cutting process. Useful quantitative values were not obtained. The measurement circle method indicates that cavitation will not occur for high hydrostatic loads such as 20 or 30 MPa, which implies that the required cutting force will continuously increase for an increasing cutting velocity. The main recommendations are introducing the Biot poroelastic equations and heterogeneity into a 3D discrete element model. Quantitative estimations for the specific energy and pore pressures during the cutting processes should be obtained. Execution of laboratory tests of rock cutting under varying hydrostatic pressures is of most importance to check the performance of the numerical rock cutting models.

Successful search and exploitation for hydrocarbons form the subsurface demands the acquisition of a thorough understanding of the basin’s geology, attainable by analyzing critically the stratigraphic framework and facies architecture of analog outcrops and mature fields with a dense network of wells. In this study Petrel was used to construct such a conceptual facies model for the Breathitt Group in the Central Appalachian Basin, with the aim of investigating the pattern of depositional environments and how they influenced the vertical and lateral distribution of facies in the foreland basin. The model provides excellent guidelines to the distribution of depositional energies in analogous subsurface progradational coastal-plain and fluvial-deltaic reservoir sequences. The study area is an appropriate analogue used by many oil and gas companies to understand and solve stratigraphic problems in subsurface coal mines and coal-bearing hydrocarbon reservoirs. Cored borehole data from 12 quadrangles in Eastern Kentucky was loaded into Petrel to generate vertical sedimentological logs. The logs were correlated using extensive coal seams and marine flooding surfaces to obtain stratigraphic columns of the strike and dip sections of the basin. 3D stratigraphic surfaces and isochore maps, embedded with pie-charts, were generated to quantify the proportions of lithofacies along every well that wholly penetrates any given isochore, including the determination, prediction and interpretation of lateral and vertical distribution of facies, depositional energies and paleo-environments. Basic principles of sequence stratigraphy were applied to explain the role and interactions of tectonics, subsidence and eustasy in the evolution of the delta system in the foreland basin. Results show that differential subsidence, including active tectonics (orogenesis) and quiescence gave rise to two broad depositional systems. The upper system, which is predominantly composed of immature sediments, was deposited by braided and meandering streams from the tectonically active thrust-front in the southeast toward the northwest in a fluvial-deltaic environment, whilst the lower system is composed of mature sediments whose deposition was mainly influenced by waves/storms and tides from the sea in the northwest that frequently transgressed the subsiding basin during the long periods of tectonic quiescence. The stratigraphy further shows a tendency to increase slope inclination and a series of anticlinal and synclinal structures, mainly in the upper system, which may provide reservoir traps or control the dynamics of fluid flow in the basin. The analysis shows that the fluvial-deltaic system has better reservoirs with a good vertical and lateral connectivity than reservoirs in the lower coastal-plain system, where vertical connectivity and permeability, is hindered by the thin laterally extensive shales between units. Nevertheless, this system could provide a good source region for the generation of hydrocarbons, due to its high content of organic matter and depth of burial, offering optimal pressures and kitchen (enough heat energy) for the generation of hydrocarbons. Facies analysis using isochores and pie-charts may be applied during both frontier exploration and exploitation phase to provide a simple and quick method of reserves estimates based on the predicted geometrical dimensions of reservoirs and non reservoirs. The method yields important petrophyical parameters that can assist reservoir engineers to design simulation models required for optimal well spacing and positioning, well numbers and better enhanced oil recovery (EOR) methods.

At interfaces between porous media acoustic energy can be converted into electromagnetic energy or vice versa by the electrokinetic effect. Operators exist describing this conversion, however these act on (one-way) upgoing and downgoing waves, while in nature only the total (two-way) wavefield exists. In this thesis mathematical formulations are developed for the source decomposition operator, describing the relation between the two-way source wavefield and the one-way downgoing wavefield, and for the receiver composition operator, describing the relation between the one-way upgoing wavefield and the two-way wavefield at the receivers. The behavior of these operators is visualized by numerical modeling.

An ever-increasing number of cables and pipelines are being laid on the bottom of lakes, channels, rivers, seas, and oceans. Various hazards threaten these pipelines and cables, which in case of occurrence can cause (severe) environmental and/or economic damage. Pipelines and cables can be protected against these attacks by dumping protective rock layers over the pipelines or cables. The main hazard concerning this research is the attack of a dragging anchor preceded by the cutting process of the anchor chain while dragged over / through the rock cover. For dragging anchors the effect of any lifting force is detrimental to its holding capacity. A good design of the rock cover can reduce the cutting of an anchor chain in the rock cover, resulting in an earlier lifting of the anchor. No generally applicable design tool exists for dimensioning these rock covers and especially in relation to anchor chains. Therefore the objective is set to find and test a theoretically based relation for the interaction between an anchor chain and a protective rock layer. The simplified solutions for describing the interaction between an anchor chain and clay are used as a basis for the interaction between the chain and rocks. The interaction forces are described as uniformly distributed forces in parallel and lateral directions of the anchor chain. There are several types of rock covers feasible but the loosely dumped rock cover on top of the existing seabed is chosen for this research. The bearing capacity of the rock berm is modelled as the bearing capacity of a strip footing on a shallow foundation. Since the bearing capacity equations do not provide information of loads in the lateral direction to the strip footing the formulas are adjusted to the research situation. A theoretical model with dimensionless normalized axis is used. The model describes a failure curve with all possible combinations of parallel and lateral forces applied to the rock berm by the anchor chain and normalised by the bearing capacity of the rock berm. A physical model has been designed to validate the theoretical model. In the physical model five different anchor chains have been dragged through three different sizes of rock covers with a few different constant anchor holding capacities. The forces on both sides of the rock cover are indirectly measured by the load cells on both sides of the model. The guiding wheels in the model cause significant friction in the model during dragging. In experiments without the presence of a rock cover a friction factor is determined to quantify the force loss over a guiding wheel. This friction factor lies within a range of 0.10<friction factor<0.16. It turned out that this friction factor has a major influence on every single data point when plotted in the theoretical model plot. However correlation is found between the data sets acquired by the experiments and the normalized failure curve presented above with the use of a semi-arbitrarily determined friction factor for each experiment. The semi-arbitrarily friction factor lies within the range specified above and is only changed when structural modifications to the model are made. The bearing capacity of the rock berm, which is mainly influenced by the effective width of the anchor chain and the internal friction angle of the rocks, only determines the location of the acquired data in the theoretical model plot. Different bearing capacities scale the dataset into the origin. Because of the uncertainty of the exact bearing capacity of the rock cover research on this subject is recommended. With the bearing capacity known the location of the acquired dataset on the theoretical normal plot can be determined. It is also recommended to do new physical model tests in which the forces on both sides of the rock berm can be directly measured eliminating the effect of friction in guiding wheels.

The past five decades an unparalleled growth in societal demand for raw materials occurred which led to sometimes-irreversible negative impacts on the earth’s ecological system. Consequently sustainable issues are of growing importance in the world and this awareness is present among customers of IHC Merwede B.V. (IHC), their customers start to demand sustainability to be incorporated in products and services. IHC intends to anticipate to this growing future demand and to invest in building up knowledge and implementing sustainability in their products and services. An Alluvial Mining Operation (AMO) has an inevitable impact on the complex ecological (environment, landscape) and social (local communities) systems. To understand such systems and implement sustainability into practice, more knowledge is required. An extensive review of literature on sustainability currently in use by the mining industry, specific characteristics in the alluvial mining industry, and improvement opportunities for a more sustainable approach have led to a sustainable guideline for AMOs. The following main conclusions concerning the sustainable guideline were identified: Sustainable issues in the mining industry can be applied very well in AMOs. During the operation phase material handling and water management are key parameters for a sustainable AMO. The International Finance Corporation stakeholder engagement process and performance standards are very functional tools during the exploration and feasibility study phases. The framework of the International Council on Mining & Metals is globally most utilized and can be applied during all mining phases. Improvement opportunities are: A better understanding of the ecological and social system is required. Notice that relevant data collection about the system is time consuming. Initiatives such as Building With Nature will help to gain more knowledge and insight in the (eco)system; A corporate mind of sustainability for all related stakeholders, on and off-site, is essential during the whole mine life; Backcasting is a useful method to road-map community projects to maximize societal value; Land-based AMOs alternative, self-generating energy sources are very interesting opportunities; For dredge mining equipment opportunities as essential sustainable parameters are reduction and minimization of emissions, turbidity, material stewardship and improved energy efficiency; and in every country with the potential for placer mining it is recommended to establish specific SD guidelines for each specific ecosystem that occurs. Due to the continuous and concurrent reclamation method only a small amount has to be reclaimed for complete closure. The South African department of minerals and energy developed a useful guideline to estimate closure costs. For further research the Gold Sands project in Peru is chosen to verify the validity of Sustainable Development issues in AMO. The main conclusions concerning the sustainable cash flow model are: Data collection to valuate sustainable indicators that affect the cash flow is difficult. The required social related data is eventually only applicable for Peruvian mining operations. Despite the difficulties for sustainable data collection, a sustainable cash flow model has been developed successfully. The mining systems selection tool serves both integrated investment analysis and production planning. The effect of alterations in the selection tool is clearly visualized in the plotted graphs. Project’s economic viability is positive within the sustainable case and the sensitivity analysis shows that sustainability is not a key parameter that influences the viability of the project.

This study focuses on the shear strength of the Bremanger sandstone used as rockfill for a crane walkway. The rockfill was tested in a small (100*100*40mm) and a medium scale (500*500*400mm) direct shear boxes to quantify the effect of particle size, packing density and uniformity, specimen size, and normal stress on strength. The laboratory data were fitted with four different models (Mohr-Coulomb Model, Power Curve Strength Model, Hoek-Brown Model and Barton Model). The Hoek-Brown model, initially developed for rock masses, was found to be suitable for rockfills. Finally, a crane walk-way was simulated with Plaxis 10 Beta version to assess its stability.

Forward modelling demonstrates that resistivity anisotropy has a huge effect on Multi-Transient ElectroMagnetic step and impulse responses. The earth is never isotropic – even a stack of isotropic layers behaves anisotropically – and there is a great need to ccount for resistivity anisotropy in order to delineate the true target depth and target transverse resistance in ElectroMagnetic surveying. I account for resistivity anisotropy by (a) deriving apparent anisotropy formulae and using them together with apparent resistivities for a fast iterative inversion scheme, and (b) by including anisotropy into a 1D full waveform inversion scheme. Full anisotropic inversions result in much smoother models than isotropic inversions. Sharp resistivity boundaries result in anisotropy anomalies, as horizontal and vertical resistivities are not affected in the same way. Anisotropic inversion results yield a good indication of the present background anisotropy. Carrying out inversions with fixed anisotropies, e.g. determined in a free anisotropic inversion, can improve the result significantly compared with an isotropic inversion.

This work is based on the idea that an acid mixture of hydrochloride and sulpheric acid react with the calcite in a chalk oilfield to create anhydrite which has a larger molecular size. This will clog the present fractures to prohibit that these fractures sometimes shortcut the injected water from the injector well to the producing oil well which otherwise would result in artificial thieve zones. In this work mass balance calculations and experimental lab work has been done to see how the acidic reaction works. It is concluded that during the conversion of calcite to anhydrite 60% of the resulting CO2 is dissolved in the present liquid; the rest is in the gaseous phase. The samples of fractured chalk are approximately 30 cm long and have a diameter of 10 cm. The fracture is situated in the flow direction. The samples are tested under reservoir conditions, and the flow rate of the acids is 2 ml/min. The resulting permeability change indicates that the fracture is sealed after half an hour of acid injection, but this seal in the fracture is only a pasty substance clogging the flow. After approximately six hours of injection the first wormholes appear and the fracture is totally sealed. Mass change is calculated based on the amount of anhydrite created during acid injection. The mass changes are equivalent to the mass change measured during the experiment. CT-scans are made before, during and after many experiments and each scan series of approximately 300 images. These images are used in a specially written program to divide all present volume components in the chalk: fracture, calcite, anhydrite, wormholes and fossils. They are also used to calculate volume percentages, and coincide with the calculated weight percentages. Fracture experiments under reservoir temperature and pressure conditions and Brazilian tests under atmospheric are done on the sealed samples to see if the fractures can be reopened. The samples were tested with an annular pressure of 310 bar, 80oC and injection pressure of 270 bar. The production pressure was released, even with a pressure difference over the core of 160 bar and did not fracture. The tensile strength of the sealed samples proved to be as strong as original chalk samples without fractures.

The effect solutes have on the properties of solvents. The properties of pure solutions (with no solvent in it), a non-electrolyte solution and an electrolyte-solution are compared and discussed. Also a detailed information why these properties change.

Knowledge of the complex subsurface is becoming increasingly important: for hydrocarbon exploration, possible storage of CO2, and the production of water for geothermal heating and energy production purposes. An example of a complex reservoir is a reservoir formed by alluvial fan sediments. Although research into alluvial fan deposits has been conducted, the geometry and sedimentary environment of alluvial fan deposits is still not completely understood at this time. 3D modelling of these sediments will contribute to the knowledge of alluvial fan reservoirs and give predictions of inter-well connectivity, hence improving production. To gain a better understanding in the reservoir architecture of alluvial fan deposits, an outcrop study in the Sis-palaeovalley, in the Tremp-Graus Basin in the Southern Pyrenees was conducted. An outcrop wall with a studied height of approximately 220 meters, in an area with a length of 1200 m and a width of 950 m, is investigated and mapped by using lithostratigraphic logs, photo panels and correlation observations. By analysing the gained data, a 3D reservoir architecture computer model is built giving a representation of an alluvial fan reservoir. Four lithofacies are encountered in the field: the conglomerate-, sandstone-, siltstone-, and limestone lithofacies. In the lower part of the outcrop the stacking of the sediment layers is farther apart compared to the upper part of the outcrop. This stacking pattern can be explained by a combination of climatic and tectonic events because of their mutual influence on the accommodation space, relative base level, and sediment supply. The built model gives insight in the alluvial fan outcrop and can form an analogue for alluvial fan reservoirs. With the improved knowledge and understanding of the reservoir architecture of alluvial fan deposits an increased production of water or hydrocarbons from alluvial fan reservoirs can be achieved, with a more sustainable well planning.

Geothermal energy is hot and sustainable. A recent run for licences has sparked questions on the optimisation and recovery of geothermal energy from the subsurface of the Netherlands through optimal project placement. The effect of heterogeneities on interference of geothermal projects in the West Netherlands Basin and the target Early Cretaceous Delft Sandstone Member has not been sufficiently studied. The objectives of this study are: (1) to gain a better understanding of the geological setting, the depositional setting and the heterogeneities of the primary target Delft Sandstone Member; (2) to show the effect of heterogeneities in the subsurface on interaction and interference of flow on closely placed geothermal systems; and (3) to build a subsurface dynamic reservoir model with which optimal well performance and placement can be assessed. The basin evolution, depositional setting and depositional processes of the Delft Sandstone Member are determined by combining the available data. The seismic, well, core and cutting data are combined to build a static 3D reservoir architectural model of the Delft subsurface. The static model is incorporated with the flow characteristics from petrophysical log data and used for temperature and fluid flow behaviour simulations. By modelling flow and temperature behaviour, the flow rates and production temperatures of a single geothermal system and the interference of the different geothermal systems were determined and quantified. This study gives new insights and a better understanding of the reservoir architecture of the Delft Sandstone Member. The Vrijenban Syncline is the predominant structure in the Delft subsurface and the sediments of the Delft Sandstone Member are deposited by a meandering fluvial system in three different depositional settings, controlled by tectonic movement. The depositional characteristics related to subsidence and accommodation space increase can have a large impact on the reservoir behaviour of the Delft Sandstone Member. It has therefore been chosen to include this effect in the model. From the flow simulations in the Delft Sandstone Member it shows that different geothermal systems closely placed within one reservoir will have pressure interference. From this study it is concluded that multiple geothermal systems can be placed in one reservoir and sustain economic production temperature for over 30 years. Different geothermal systems in one reservoir will however communicate in the reservoir creating both positive and negative effects on flow that are large enough to respectively improve or badly affect the economics of a project. The results of this study will be a base case for further research as it will form a benchmark for future local and regional geothermal studies. Simulations of multiple well configurations to determine optimal well placement can now be performed. This will ensure and provide the foundation for a true roll out of geothermal systems through the western parts of the Netherlands.

The use of cobbles as a dynamic revetment is a recent development in coastal protection. Cobbles are placed along the beach and they form a dynamic equilibrium with the waves, thus dissipating the energies from the wave and protecting the soft, native material from eroding. In order to optimize the design and increase the durability of this method, it is important to obtain information on the long term behaviour of the cobble beaches in a reliable way. In this research the efficiency of using terrestrial laser scanning (TLS) to acquire a detailed model of the cobble beach and extracting information from it will be explored. Using a 3D terrestrial laser scanner, a dense point cloud of the cobble beach can be generated. Then through scan registration, data processing (e.g. removal of outliers) and surface reconstruction a solid model will be created. The volume of the solid can be calculated and compared to the volume of a subsequent scan to identify any changes. Finally the validity of the model will be verified by comparing roughness profiles obtained from a laser sensor and the profile obtained by cutting the surface of the model.

Wintershall is operating a number of Buntsandstein fields in the Southern North Sea. It has proven a major exploration challenge in the area to predict the reservoir quality of these fields based on seismic data only. The effect of salt present in the area plugging the pore space leads at first sight to similar seismic responses on post-stack data as for gas filled reservoirs. This study aims to gain better insight into the (subtle) differences in seismic response induced by water-, gas- or salt-fill scenario. The approach adopted is by studying the seismic response at various existing wells in one of the fields and the corresponding seismic responses of the processed 3D seismic survey. First a thorough analysis of the log responses of 13 wells is made and the effect of a.o. depth trends, compaction, diagenesis and facies changes to the seismic response is qualitatively investigated. Then, a match between the log data and the poststack seismic data is established by creating synthetic seismic data. Finally by using fluid substitution and more recent solid substitution theory, subtle changes in seismic response, both pre-stack and post-stack, between the different porefills are predicted. Based on these modeled predictions recommendations are made concerning the type of data analysis that should be carried out to discern the different porefills on the seismic data. The results of this research should lead to an improved characterization of the Buntsandstein reservoirs and as a consequence, to a higher success rate in drilling (i.e. less “dry wells”).

The Delft Geothermal Project is an ongoing study in search for the best way to produce renewable energy from the Delft Sandstone Member. So far, a homogeneous reservoir model, a study of the regional geology and a study of the fluid flow and heat transfer have been made. For these studies, information is used from the Moerkapelle oil field located twelve kilometers to the east of Delft. Because of the oil production there, a wealth of subsurface data is available. This thesis used for the first time borehole cuttings data from the well DEL-03. DEL-03 is less then one kilometer away from the proposed drill site. The aim of this thesis is to discover vertical heterogeneity within the Delft Sandstone Member with a sediment-petrographical analysis. With the use of thin slides of the cuttings of DEL-03 a sedimentary analysis has been made using a polarizing microscope. It goes more deeply into mineralogical content and cement types. Examination of the cuttings with fluorescent light and chloroform proved the absence of residual bitumen, which is a needed for the production of hot water. Also a grain size analysis has been made which was inconclusive. The content of sandstone in the borehole cuttings analysis does not correspond with the results of the spontaneous potential log of DEL-03. Siderite present as cement in these sections is the cause of this contradiction. The siderite cement has a high influence on the porosity and permeability which is also concluded in the petrographical study of thin slides of plugs of MKP-11. Porosity is detected with the use of the software Image Analysis while the permeability is calculated with the Karman-Kozeny equation. The porosities in the upper part of the Delft Sandstone Member beneath Moerkapelle showed relatively high values and therefore a relative high permeability. The results of this thesis can be used, together with the many images gathered, as a database for a heterogeneous reservoir model.

Due to the extreme sensitivity of the superconductive gravimeter GWR T020, based at Metsähovi Research Center in Kirkkonummi, Southern Finland, various local meteorological and hydrological changes influence or disturb its measurements. This study is part of a large research project which aims to identify the contribution of the local hydrology at Metsähovi to these gravimeter measurements. For this purpose a study is made to investigate the geological structure of the subsurface and the hydrological properties of the stratigraphic layers. In order to perform numerical calculations a digital model is made using digital modeling software. A field investigation is performed consisting of: • A literature study on hydro-geological setting in Southern Finland. • An extensive fieldwork consisting of bore holes, field observations and various field measurements (among others GPS, GPR, slug tests and monitoring of soil moisture with soil sensors). • Laboratory work to obtain necessary soil properties. Main property which was found is the grain size distribution. A large amount of data is gathered and processed in order to integrate the data into a structural model. A method is found to integrate a maximum amount of information into a model and by optimally using the understanding and knowledge of the geological setting. A model is constructed with several layers. The area can be characterized in two hydrogeological domains. One is the higher area where overburden is thin and only till covers the bedrock, the other is a lower area dominated by a low permeable silt and clay layer. The till is low permeable but is still found to infiltrate water considerably. The hydrological setting of Metsähovi is analyzed and theories of the hydrogeological processes which govern moisture changes in the area are investigated. Main focus is how these processes can be modeled with their governing laws and parameters. It is recommended to initially make a 1 dimensional model with software such as CoupManual.

This project focuses on the shear strength of Devonian sandstone cobbles that will protect the area between the sea-water breaker and the beach and will be used to construct a runway for a large crane for the new Maasvlakte 2. In rock slope design the shear strength of sliding interfaces is often based on Coulomb’s model in which shear strength (τ) is expressed as a function of cohesion (c), normal load (σ) and the friction angle (Ф). A specific model on shear strength behaviour of rockfill is proposed by Barton (Barton, 2008). Barton’s model can be used to predict shear strength of rock joints and rock fill when basic rock properties are known. One main factor of influence on shear strength of rockjoints and rock fill is the basic friction angle. A Golder direct shear box was used to obtain the basic friction angle of the Bremanger sandstone. First the basic friction angle was determined (using flat saw-cut surfaces). In the next phase fresh tensile cracked rock discontinuities were tested. Measured stresses were corrected using measured dilatancy to estimate the basic friction angle. The influence of different rock properties such as roughness, rock strength and visible layering was studied. Finally natural non-matching surfaces were researched to see how the shear strength changes due to the weathering and smoothening of the rock. The following main results and conclusions were drawn from the research project: Flat saw-cut surfaces: - The basic friction angle of the Bremanger (flat saw-cut surfaces) was not measured correctly. Since the sample halves were polished in order to make them match, the measured friction angle is rather an indication of the polishing process than the rock properties. Tensile-cracked surfaces: - For the tensile cracked samples, the average residual friction angle is 1111 degrees. The residual friction angle was used as the basic friction angle rather than the peak friction angle since high peak shear stress values are caused by asperities at the edges of the tested samples. The shear strength dropped massively as soon as these asperities broke off. - Residual friction angles do not depend on wet or dry test conditions. - There is a direct link between UCS and shear strength. The higher the UCS value, the higher the residual stress value. - The Bremanger sandstone is a Metasandstone. Layering is still macroscopically visible but cleavage does not occur along this layering. Natural non-matching surfaces: - These surfaces were weathered and smoothened. This caused the residual friction angle to drop to 1111degrees. 3D Leica pictures confirmed that the surface of this tested sample was smoother than the fresh tensile-cracked ones.