This thesis tells the hitherto neglected story of onshore oil exploration in the British East Midlands from 1908 to 1964. Drawing on a series of case studies it provides a regional historical geography, connecting science and industry to the exploratory field science of geology. During the period examined, two low key discoveries – Hardstoft, in Derbyshire (1919), and Eakring, in Nottinghamshire (1939) - altered Britain’s energy prospects, supplementing coal with liquid mineral oil. Using archival research methods and oral testimonies, the thesis reveals how a diverse assemblage of earth scientists, oilfield technologies and techniques, institutions and private companies developed a regional laboratory for oil exploration. Liquid energy fuelled heated political debates over land nationalisation and private ownership rights, the science of subsurface quantification and governance, and the role of industry in exploration. Though small when compared with global consumption and production figures, oil discovered in the British East Midlands provided a time critical supply of oil during World War Two. It also facilitated technological advances in oilfield development, contributed towards a new arm of economic geology (geophysics) and encouraged earth scientists to think of territory as a three dimensional entity, extending beneath, as well as along the land surface.

An investigation was undertaken to examine the performance of a Fresnel reflection sensor (FRS) incorporated into a differential scanning calorimeter (DSC) to track the cross-linking of epoxy resins. The initial design used a micrometer translation stage to lower the FRS through an orifice in the DSC platinum lid and onto the pan containing the sample. During exothermic cross-linking experiments, the resin refractive index and the heat evolved were measured simultaneously, allowing for direct comparison between the data. Combining the two measurement techniques produced a powerful hyphenated analytical procedure that demonstrated the feasibility of using the FRS for in-situ cure monitoring of epoxy resin systems. During the cross-linking of specified resins, the sensor revealed optical phenomena throughout the latter stages and was shown to be sensitive to the glass transition temperature, nano-particulate movement, nano-particulate concentration and phase separation. Therefore, the introduction of the FRS to the DSC provided valuable cross-linking information. A second modification to the DSC permitted the accommodation of an optical fibre probe, which facilitated simultaneous DSC/FRS/Fourier transform infrared spectroscopy (FTIRS) analysis. Good correlation between the cross-linking kinetics of an epoxy resin system was demonstrated using the hyphenated techniques and hence alleviated the issues of cross-correlation between individual experiments.

This thesis details work that was carried out to optimise the fracture toughness and thermal stability of a new maraging steel called F1E. This steel was designed to precipitate Laves phase to improve the creep properties, and it was initially found that this was detrimental to toughness properties, and that further precipitation occurred during extended time at desired operating temperatures, embrittling the alloy. Initial work focussed on development of a heat treatment to stabilise the Laves phase, using a slow cool to the service temperature to fully precipitate the equilibrium volume fraction of Laves phase at this temperature without nucleating fresh particles, as it was believed that it was fresh particles forming during service which led to the loss of ductility after thermal exposure. This heat treatment process successfully stabilised the properties. Modifications were then made to the composition in an attempt to improve the ductility and toughness without losing strength or creep performance. Two changes were made - an increase in the nickel content, as increasing the concentration of nickel in the matrix of maraging steels has been shown to improve toughness; and a decrease in molybdenum and tungsten content to reduce the Laves phase volume fraction by 25%. These changes, along with further optimisations of the heat treatment used and refinement of the prior austenite grain size, were successful in improving the fracture toughness of F1E (or RR9922 as the modified composition is known) by a factor of 2, from 23 MPa m\(^0\)\(^.\)\(^5\) to 46.9 MPa m\(^0\)\(^.\)\(^5\).

Two phase alpha/beta titanium alloys are used in a wide variety of applications such as aerospace, biomedical, gas turbine engine, sport and energy. These alloys have high specific strength and specific modulus as compared to magnesium and aluminium alloys as well as excellent corrosion resistance. The Ti-6Al-4V (α+β) alloy is the most widely used and the best known of all the Ti alloys. Although there are a number of observations in the literature reporting the mechanical responses of these two phase alloys, there exists very little understanding of the mechanisms of the individual phases and the alpha/beta interface’s role in strengthening. Additionally, it has often been reported in the literature that ‘smaller is stronger’ for different metals due to the presence of a size effect. There is no real understanding of the mechanism of the size effect in the alpha-beta titanium and HCP and its dependence on orientation. Single alpha, beta and alpha-beta colony micro-pillars have been manufactured from a polycrystalline commercial Ti-6Al-4V sample using Focused Ion Beam (FIB). Alpha/beta pillar contained two alpha lamellae separated by a thin fillet of beta phase. A nano-indenter was then used to conduct uniaxial micro-compression tests on Ti alloy single crystals, using a diamond flat tip as a compression platen. By controlling the crystal orientation along the micro-pillar using Electron Back Scattering Diffraction (EBSD) different slip systems have been selectively activated. The advantage of the micro-compression method over conventional mechanical testing techniques is the ability to localize a single crystal volume which is characterisable after deformation. This study makes a contribution to knowledge in several key areas, including an understanding of the mechanical response of different crystals at micro/submicro-scale, the effect of phase interfaces on deformation, and an understanding of the strengthening mechanism in two-phase Ti alloys, the orientation size effect in HCP metals and the CRSSs for each phase in Ti-6Al-4V. Therefore, in order to evaluate the behaviour of these alloys for future applications, it is imperative that the microstructural features and characteristics be quantified and examined on a small scale. The results showed that the beta phase in between alpha lamellae caused strengthening deformation. When the surface normal is parallel to the [0001] of the single alpha crystal, the material deforms with difficulty in the [0001] direction of the single alpha phase. The mechanical responses of the alpha, beta, and alpha/beta crystals not only depended on the size of the pillars, but also on the crystallographic orientation, the initial dislocation density and the relationship between the two phases in the case of α/β crystals. Extensive electron microscopy investigation revealed that the anisotropy in basal and prismatic slip systems can be directly correlated with the transmission of dislocations across the single crystal, the beta laths, and the accumulation of residual dislocation content near the interfaces and in the single beta phase. This information is essential in order to better model mechanical deformation in these materials. In addition, dislocation analysis indicated that the deformation of individual grains conformed to the Schmid factor (SF) analysis where slip primarily occurs on those slip systems where the resolved shear stress (SF) values are highest. The results presented in this thesis bring to light several concerns for designing with titanium alloys and identify a number of phenomena of strong scientific interest. They will allow for the development of realistic models for the mechanical behaviour and provide a comprehensive analysis that can contribute to the theoretical development of the design and enhancement of the titanium allows. Moreover, the role of crystallography in plastic deformation provides a novel insight into the nature of the orientation size effect in HCP. This work points towards the need for further investigations into the higher and lower temperature deformation behaviour of Ti-64 to fully understand the phenomena identified within this study.

Oil is a major source of energy around the world. With the decline of light conventional oil, more attention is being paid to heavy oil and bitumen, as a good alternative to light oil for energy supplies. Heavy crude oils have a tendency to have a higher concentration of metals and several other elements such as sulfur and nitrogen, and extraction of these heavy oils requires more effort and cost. The Toe-to-heel Air Injection catalytic upgrading process In-situ (THAI-CAPRI) is an integrated process which includes recovery and upgrading of heavy oil and bitumen using an air injection process, and horizontal injector and producer wells. Since the process works through a short distance displacement technique, the produced oil flows easily toward the horizontal producer well. This direct mobilized oil production and short distance are the major properties of this method which lead to robust operational stability and high oil recovery. This technique gives the possibility of a higher recovery percentage and lowers environmental effects compared to other technologies like steam based techniques. A catalyst plays a crucial role in the THAI-CAPRI technique to be successfully conducted. However, heavy coke can be formed as a result of the thermal cracking of heavy oil occurring in the THAI-CAPRI process, and a catalyst resistant enough to use in CAPRI needs to be developed. Therefore, there is a need to understand the pore structure to achieve a high catalyst quality, to obtain a structure that directly affects the fluid behaviour within a disordered porous material. In this study, novel experimental techniques were used to obtain greater accuracy results, for the information obtained from gas adsorption curves by using a combination of data obtained for two adsorptives, namely nitrogen and argon, both before and after mercury porosimetry. This new method allows studying the effect of pore-pore co-operative during an adsorption process, which significantly affects the accuracy of the pore size distributions, obtained for porous solids. A comparison, between the results obtained from the characterisation of a mixed silica-alumina pellet and those obtained from pure silica and alumina catalysts, were presented to study the effects of surface chemistry on the different wetting properties of adsorbates. The pore networks within pellets invaded by mercury following mercury porosimetry have been imaged by computerized X-ray tomography (CXT). It was noticed that the silica-alumina catalyst had a hierarchical internal structure, similar to that for blood vessels in the body. To validate the findings of the pore geometry characterisation obtained from the new method, several techniques, such as cryoporometry, gas sorption isotherms, and mercury intrusion experiments, were considered. Further, a novel well design consisting of two horizontal injectors and two horizontal producers was used in different well configurations, to investigate the potential for improved efficiency of the THAI process on the heavy oil recovery. A 3D dimensional simulation model, employing the CMG-STARS simulator, was applied in this simulation. Two horizontal injectors and producers were designed in this project, instead of horizontal injector and producer were used in the Greaves model (the base case model), to investigate the effect of the extra injector and producer on the performance of the THAI process. It was found that the locations of the well injections and the well productions significantly affected the oil production. For the study of the effectiveness of the catalysts in the oil upgrading process, the CAPRI technique has been simulated to investigate the effect of several parameters, such as catalyst packing porosity, the thickness of the catalyst layer and hydrogen to air ratio, on the performance of the CAPRI process. The TC3 model used by Rabiu Ado (2017), which was the same model used in the experimental study of Greaves et al. (2012), was also used in this study. The Houdry catalyst characterised by the experimental work was placed around the horizontal producer in this simulation.

The accepted design techniques for bulk solids handling equipment are frequently overlooked during the installation of industrial process plants. As a result, flow unreliability is often observed in silos in the form of flow stoppages, product bulk density variations, formation of rat-holes, flushing, flooding and product segregation. In most cases when these problems are detected in silos, they are the result of a discharge pattern known as core flow, where localised flow channels promote the preferential draw of material from certain zones of the silo, with the rest of the material remaining stagnant. Coal handling is not the exception and process equipment is not always designed to cope with the often variable characteristics of the coal, which is frequently processed in a large variety of forms, with particle sizes ranging from fine dust to a top size several inches and other parameter like moisture content varying from completely dry to dripping wet. In order to solve the problems caused by core flow, the discharge behaviour of the silo needs to be modified to produce a uniform movement of all the material, to achieve a flow pattern known as mass flow. Static inserts have been proved to be an effective method of modifying the discharge patterns in silos, but their use and design procedures are not well understood or are well hidden behind patents and trade secrecy. This research project aims to produce practical guidelines for the design and positioning of static insert to improve flow in silos. The work presented in this thesis follows an experimental approach where the performance of an insert is first evaluated at bench scale in a 3 litre model silo and then validated at semi-industrial scale in a 400 litre test rig. The bench scale model allows the evaluation of numerous changes in insert morphology and positioning at relatively low costs, facilitating the development of practical rules for their design. Following this approach a design procedure for inverted cone inserts is proposed as a modification of a method developed by J. Johanson [Johanson, 1965]. A performance comparison was undertaken both at bench and semi-industrial scales with inserts designed following Johanson’s method and the modified method proposed by the author. The results showed that both inserts were capable of producing mass flow in an otherwise core flow silo, but the modified insert produced more consistent results, particularly with lower heights of powder bed. This experimental approach was also followed to develop a novel type of insert called open double cone which maximizes the area of influence of the insert inside the silo facilitating flow. For this insert, three design procedures where proposed with each of them producing inserts capable of achieving mass flow in the bench scale model. The main difference between the inserts produced by the three procedures, was the size of the insert in relation to the volume of the silo hopper. In a similar way, two procedures were also proposed for the design of double cone inserts, with the resulting inserts capable of achieving mass flow in the bench scale silo. Then, a prototype of an inverted cone designed with the modified method, a prototype of the open double cone and a prototype of a double cone were tested in the semi-industrial scale test rig. The results at both scales showed that the open double cone and the double cone inserts outperformed the inverted coned, by producing more uniform velocity profiles across the silo and also producing more consistent flow rates. Although the performance between the open double cone and the double cone was very similar, the open double cone was more consistent in producing flatter velocity profiles and also the double cone was more prone to produce slightly off centre discharges. The procedures proposed for insert design provide the tools needed to apply insert technology to industrial processes. This is demonstrated with the design of double cones which successfully eliminated rat-holing problems in conical silos from an industrial pneumatic conveying system. The bench scale methodology is also employed to try to solve flow unreliability issues experienced in an industrial coal silo. For this case, a bespoke type of insert was developed to respond to the complex geometry and mode of operation of the silo. The proposed insert produced very positive results at bench and semi-industrial scales, laying the bases for a solution for the full scale silo.

Thousands of employees in small and medium-sized enterprises (SMEs) in Indonesia’s tin mining industry are working in dangerous environments without an adequate safety and health protection programme. Occupational safety (OS) has become a primary focal point when it comes to preventing dangerous incidents. Such incidents can lead to serious injuries and fatalities, particularly given that mining involves dangerous and high-risk activities, for example, in onshore tin mining, working in muddy areas with heat, humidity and a risk of landslide. Studies addressing the health and safety domain in Indonesia and the mining sector have the least number of ergonomics applications. The research examined the existing OS of a state-owned tin company, namely PT Timah, in Indonesia. The company has a relatively good level of experience in practising tin mining operations, and also employs occupational safety programmes. For approximately a decade, this company has collaborated with 16 private onshore SMEs which work in more than 400 locations under the PT Timah cooperation scheme. Despite applying OS and a health programme in the main company, the same programme has not been included in the tin mining operation cooperation scheme that regulates the rights and obligations of SMEs. This thesis examines the possibilities of using a well-established ergonomics approach and adapting it so that it is more frequently accepted and embraced in Indonesia. The research is focused on the participatory ergonomics (PE) approach as applied to SMEs. Postal data reviews, interviews and observation methods were used to examine the current status of OS in the Indonesian tin mining industry. The scenario-based design (SBD) method was used to investigate the acceptability of PE, while the two-round Delphi technique was applied to reach a consensus on the practical implementations of PE solutions. There is positive acceptance of PE among workers in Indonesian tin mining companies. Regular working safety dissemination through a kinship approach and specific safety training is recommended for resolving communication, cultural and knowledge issues related to OS. In addition to this, a consensus was reached on proposed solutions regarding the implementation of PE within the Indonesian tin mining industry, such as evaluation of the remuneration and bonus system, employing the train-the-trainer programme, and the OSH reporting system.

Filamentary carbon deposition on 20Cr/25Ni/Nb austenitic stainless steel from 1000-5000 ppm C2H4 in 1%CO/ bal. CO2 at 600°C has been investigated. This filamentary carbon deposition is catalysed by metallic nickel-rich particles formed intrinsically from the alloy during the early stages of oxidation. Samples were analysed using electron microscopy techniques. A simple model has been proposed to explain the formation of nickel-rich particles within the subsurface oxide layer. Furthermore, in this project the effect of COS, H2S and CH3SH on carbon deposition were examined. Addition of sulphur species suppressed the deposition process but the effect was dependent on the concentration of C2H4 and the sulphur species. This suppressing effect of sulphur on carbon deposition was explained in term of the role played by the adsorbed sulphur in reducing the rate of the key steps of the growth process of a filament.

Risers in offshore operations are subjected to corrosion during their service life cycle. The use of relatively inexpensive, high strength to weight ratio fibre reinforced polymer composite (FRPC) as a load bearing pipe repair sleeve is an emerging technology that is becoming common for offshore applications. Risers experience complex loading profiles and experimental investigations often incur substantial time, complicated instrumentation and setup costs. The main aim of this research is to develop a design tool for the repair of offshore riser that suffers from external corrosion damage on its surface using FRPC material. The simplest configuration of a fixed platform riser in the form of a vertical single-wall pipe is being considered. Characterization of the stress-strain behaviour of the FRPC laminate in the composite repair system subjected to various load profiles of a common riser is performed. The means of composite repair takes into account the ease of automated installation. The final repair method considers the use of unidirectional pre-impregnated (prepreg) FRPC that is assumed to be helically wounded around the riser. Finite element models of the composite repair system were developed via ABAQUS. Global analysis of the entire length of the riser was omitted as external corrosions usually occurs in a localised manner on the surface of the riser. Instead, local analyses were conducted where boundary conditions were applied to mimic an infinitely long cylindrical structure such as the riser. The local analyses FEA models were made to capture the stress-strain behaviour of the FRPC laminate subjected to different load profiles including static loadings such as internal pressure, tensile load and bending load. The design loads were calculated based on a limit analysis known as Double-Elastic Curve method developed by Alexander (2008). Proper element selection and mesh convergence were carried out to determine the FE model that can minimize the time and CPU memory needed for the simulation without compromising the accuracy of the results. The second part of this research integrated experimental tests to validate the FE model developed using the ABAQUS general purpose code. Due to constraints on cost and supply of materials and equipment, small-scale tests were conducted. Similitude relations were used to determine the scale properties between the model and the prototype. The final results showed that the FE model can represent the real-life tests of corroded riser repaired with off-axis FRPC laminate with great accuracy of more than 85%. Hence can be a useful tool for design and parametric study of the composite repair system. Using the validated FE model, an extensive parametric study of the composite repair system with respect to varying corrosion defects was conducted. The thickness and length of the repair laminate were compared to the ASME PCC-2 standard. Optimum thickness and length of the composite laminate were determined based on the maximum allowable strains computed using the Double-Elastic Curve method. In addition, varying fibre angle orientation of the unidirectional prepreg was considered as it is one of the main factors in helical winding. Based on the results from the parametric study, a simple relation was developed to predict the required thickness of the composite repair system subjected to combined loading. This relation combined with the developed FE model can be used to provide a quick design and performance validation of a composite repair system for offshore riser, which is the main novelty aspect of this research.

The 7175-T7351 aluminium alloy was studied to determine its suitability for the step-aside gearbox housing on the Rolls Royce Trent 1000 engine. The industrial motivation of this work was to reduce the weight of the gearbox housing using this lightweight material to ultimately improve the specific fuel consumption of the aircraft. This involved obtaining the mechanical properties of the aluminium alloy via a series of uniaxial mechanical tests with parameters based on the operating conditions of the gearbox housing during a typical flight cycle. Furthermore, a constitutive viscoplasticity model, with the inclusion of material ageing parameters, was developed to predict the material’s cyclic response under strain-controlled isothermal fatigue conditions at the gearbox housing’s operating temperatures. With this capability, a prediction for when the strength of the gearbox housing falls below the required design strength for safe use could be made. The room temperature hardness tests demonstrated the effect of time spent at elevated temperatures on the material’s hardness. It was found that the higher the soak temperature, the greater the initial rate of decrease in room temperature hardness and the lower the asymptotic value of hardness that was reached. For example, up to 24 hours of soaking at 200◦ C, the hardness decreased by 33%, and up to 1000 hours the hardness had decreased by 55%. For the same durations at 180◦ C, the hardness decrease was 17% and 47% respectively. Soaking at 120◦ C had an insignificant effect on the hardness of the material, indicating that the microstructure was thermally stable. Hardness testing could be used as a method to assess the strength of the gearbox housing for service monitoring during certifcation. Similar to the hardness tests, the elevated temperature tensile test results also revealed degradation in the mechanical strength of the alloy after prior soaking at elevated temperatures. The tests at 200◦ C on the as-received material decreased the yield stress by 31% and after soaking at test temperature for 20 hours prior to testing, the yield strength dropped by 52%. After a 2 hour temperature, the yield stress decreased from 220MPa to 165MPa which is alarming since the gearbox housing spends about 18 minutes at 200◦ C and 190MPa during climb. This suggests that in less than 6 flight cycles, the material’s strength will fall below the maximum operating stress of the gearbox housing and will be unsafe for continued use. Samples were soaked for up to 400 hours at 200◦ C and prepared for microstructural analysis. EBSD images showed that the grains were no significantly affected by the temperature exposure and showed no signs of coarsening. TEM and EDX analysis revealed that the majority of the particles within the grains were zinc-magnesium rich particles and were assumed to be MgZn 2 precipitates based on the TEM particle identification. The precipitate size and inter-particle spacing were found to increase with soak time. The change in monotonic yield strength was therefore attributed to the coarsening of these precipitates. The material characterisation suggested that, although the 7175-T7351 aluminium alloy initially appeared to have desirable mechanical properties, it is unsuitable for this or similar applications due to the rapid decrease in strength and thermally unstable microstructure. Furthermore, if an aluminium alloy is considered for this application, then it may be vital to account for material ageing behaviour. The unified, uniaxial viscoplasticity Chaboche model was implemented to predict the material response strain-controlled isothermal fatigue tests at 160◦ C and 200 ◦ C. A material ageing term was added to the model to account for the material ageing that decreased the yield strength with time. With this addition, two assumptions were made: 1) material ageing only affects isotropic hardening and 2) isotropic hardening can be de-coupled into material ageing (as a function of time at elevated temperature) and mechanical softening (a function of accumulated plastic strain). The tests at 160◦ C and 200◦ C showed that numerical and experimental results were in good agreement, providing accurate isothermal cyclic stress behaviour of the 7175-T7351 aluminium alloy. Furthermore, it was shown that the mechanical softening and material ageing components could be de-coupled. However, when the model was used to predict stress-controlled isothermal fatigue data and a cyclic stress relaxation tests, a number of deficiencies arose. The predicted ratcheting and ageing rate was greater than expected. The material ageing term may require an additional function to change the ageing rate depending on whether the material is elastically or plastically loaded. Norton’s creep power law could not predict term long stress relaxation behaviour but it was sufficient enough to describe to short- term viscous effects under the strain-controlled fatigue conditions. Despite these deficiencies, the model provided an initial point for a unified, viscoplasticity model for the 7175-T7351 alloy. Due to the rapid ageing of the material, the model could be used to predict if or when a material’s strength is unsuitable for safe operating use.