Reservoir characterization and by-passed pay analysis of philus field in Niger delta, Nigeria

Hydrocarbon resources have become the most essential commodity contributing to any nation’s growth and development in the recent years. For the past decades now, the quest for hydrocarbon resources has been increasing in an arithmetic rate that its supply can no long-er meets the demand for its consumption today. In petroleum industry, seismic and well log analyses play a vital role in oil and gas ex-ploration and formation evaluation. This study is aimed to effectively characterize the reservoirs and analyze the by-passed pay in Philus Field, Niger-Delta, Nigeria in order to look into the economic viability and profitability of the volume of oil in the identified reservoir(s). The faults in the study area trend in NW-SE direction and dip towards the south. Seven reservoirs were mapped on Philus field. A dis-covery trap and a by-passed (new prospect) trap were mapped out on the field. The petrophysical analysis showed that porosity of Philus field was 0.24. The volumetric analysis showed that the Stock Tank Original Oil in Place of discovery trap (Philus field) ranged from 1.6 to 43.1 Mbbl while that of new prospect trap ranged from 18.1 to 211.3 Mbbl. It is recommended that the oil reserve of Philus field needs to be recalculate

Independent Expert Scientific Panel – Report on Unconventional Oil and Gas

No abstract available

Aeronautical Engineering. A continuing bibliography with indexes, supplement 156

This bibliography lists 288 reports, articles and other documents introduced into the NASA scientific and technical information system in December 1982

Influence of soy protein’s structural modifications on their microencapsulation properties: a-tocopherol microparticles preparation

Enzymatic and chemical modifications of soy protein isolate (SPI) were studied in order to improve SPI properties for their use as wall material for a-tocopherol microencapsulation by spray-drying. The structural modifications of SPI by enzymatic hydrolysis and/or N-acylation were carried out in aqueous media without any use of organic solvent neither surfactant. Emulsions from aqueous solutions of native or modified SPI and hydrophobic a-tocopherol, were prepared and spray-dried to produce a-tocopherol microparticles. The effect of protein modifications and the influence of the core/shell ratio on both emulsions and microparticles properties were characterised. The obtained results demonstrated that oil-in-water emulsions prepared with modified proteins had lower droplet size (0.5-0.9 μm) and viscosity (3.6-14.8 mPa×s) compared to those prepared with native proteins (1.1 μm and 15.0 mPa×s respectively). Efficiency of oil retention decreased after protein hydrolysis from 79.7 to 38.9%, but the grafting of hydrophobic chain by acylation improved efficiency of a-tocopherol retention up to 94.8%. Moreover, higher emulsion viscosity, particle size and process efficiency were observed with the increase of a-tocopherol amount

Improving Subsurface Characterisation with ‘Big Data’ Mining and Machine Learning

Funding: This research was supported by Wood Mackenzie through funding of a Postdoctoral Research Associate position at Heriot Watt University, and through access to data from two basins. Acknowledgments: This work was supported by Wood Mackenzie through funding research collab- oration with Heriot-Watt University. All the data were anonymised and supplied by Wood Mackenzie and authors are thankful for the opportunity to publish the outcomes of this research. Authors also thank Mikhail Kanevski of University of Lausanne for the peer exchange on feature selection and the opportunities opened during his course on Machine Learning hands-on applications. Authors acknowledge the use of Orange Data Mining [27] and ML Office for SOM application [30]. We thank Susan Agar, who reviewed the paper most comprehensively and helped improve it along with two anonymous reviewers.Peer reviewedPublisher PD

Natural and anthropogenic fluid migration pathways in marine sediments

Fluids are an important agent in nearly all geologic processes that shape the planet Earth. Fluid abundance and composition are governed by flow along permeable beds or natural and anthropogenic structures in the subsurface including faults, wells, and chimneys/pipes. Spatial and temporal variations in fluid flow activity modify total fluxes between geosphere, cryosphere, hydrosphere, and atmosphere. These fluxes have broad implications for geological processes including the formation of natural resources or the occurrence of geohazards including landslides, earthquakes and blowouts. They further play a crucial role for the global carbon cycles and the climate system. A qualitative and quantitative understanding of fluid flow in the subsurface is therefore important to assess the role of fluids in the Earth system and to quantify fluxes from the geosphere into the hydro- and atmosphere. In this Ph.D. thesis I use an integrated, interdisciplinary approach to study natural and anthropogenic fluid migration pathways in marine sediments in the North Sea, the convergent Hikurangi margin, and a section of the ancient Tethys margin which is now exposed near Varna, Bulgaria. The applied methods include conventional 3D seismic, high-resolution 3D seismic, and 2D seismic data as well as hydroacoustic, sedimentological, unmanned aerial vehicle-based photogrammetric and geochemical data. In each of the studied systems, natural and/or anthropogenic fluid migration pathways allow the transport of significant amounts of fluids through marine sediments towards the seafloor. Often the co-existence of multiple pathways enables the fluids to bypass permeability barriers within the Earth’s crust resulting in the formation of structurally complex flow systems. Focused fluid flow along normal faults in the Hikurangi margin likely plays an active role in the subduction drainage system, influences the slope stability and the morphotectonic evolution of the margin. Results from the Eocene Tethys margin show that focused fluid flow in marine sediments is possible in unconsolidated sands if seepage is focused at the top of faulted units and the flux rate is high enough. This stands in contrast to the general assumption that focused fluid flow in marine sediments is limited to low-permeable sediments. In the marine environment the term fluid flow is often used to exclusively refer to the flow of hydrocarbons. However, geochemical data from the North Sea and the Tethys margin indicate that the involved fluids are of different origin including compaction-related dehydration and submarine groundwater discharge. In each of the investigated cases, the temporal and spatial evolution of fluid flow is not fully addressed yet, especially with regard to vertical fluid conduits or the safety of subsurface drilling and storage operations. The results of my thesis highlight that the investigation of fluid migration pathways requires an interdisciplinary approach which may indicate the origin of the fluids, help understand the fluxes of fluids from the geosphere into the hydrosphere and atmosphere of the past, present and future and reveal the resulting consequences for the global carbon cycles and the climate system

Multi-scale multi-dimensional imaging and characterization of oil shale pyrolysis

In recent years, oil shale has attracted renewed attention as an unconventional energy resource, with vast and largely untapped reserves. Oil shale is a fine-grained sedimentary rock containing a sufficiently high content of immature organic matter from which shale oil and combustible gas can be extracted through pyrolysis. Several complex physical and chemical changes occur during the pyrolysis of oil shale where macromolecular network structures of kerogen are thermally decomposed. The pyrolysis of oil shale leads to the formation of a microscopic pore network in which the oil and gas products flow. The pore structure and the connectivity are significant characteristics which determine fluid flow and ultimate hydrocarbon recovery. In this thesis, a state-of-the-art multi-scale multi-dimensional workflow was applied to image and quantify the Lacustrine Eocene Green River (Mahogany Zone) formation, the world’s largest oil shale deposit. Samples were imaged before, during and after pyrolysis using laboratory and synchrotron-based X-ray Micro-tomography (µCT), Optical Microscopy, Automated Ultra-High Resolution Scanning Electron Microscopy (SEM), MAPS Mineralogy (Modular Automated Processing System) and Focused Ion Beam Scanning Electron Microscopy (FIB-SEM). Results of image analysis using optical (2-D), SEM (2-D), and µCT (3-D) reveal a complex fine-grained microstructure dominated by organic-rich parallel laminations in a tightly bound heterogeneous mineral matrix. MAPS Mineralogy combined with ultrafast measurements highlighted mineralogic textures dominated by dolomite, calcite, K-feldspar, quartz, pyrite and illitic clays. From high resolution backscattered electron (BSE) images, intra-organic, inter-organic-mineral, intra and inter-mineral pores were characterised with varying sizes and geometries. A detailed X-ray µCT study with increasing pyrolysis temperature (300-500°C) at 12 µm, 2 µm and 0.8 µm voxel sizes illuminated the evolution of pore structure, which is shown to be a strong function of the spatial distribution of organic content. In addition, FIB-SEM 3-D visualisations showed an unconnected pore space of 0.5% with pores sizes between 15 nm and 22 nm for the un-pyrolysed sample and a well-connected pore space of 18.2% largely with pores of equivalent radius between 1.6 µm and 2.0 µm for the pyrolysed sample. Synchrotron 4-D results at a time resolution of 160 seconds and a voxel size of 2 µm revealed a dramatic change in porosity accompanying pyrolysis between 390-400°C with the formation of micron-scale heterogeneous pores followed by interconnected fracture networks predominantly along the organic-rich laminations. Combining these techniques provides a powerful tool for quantifying petrophysical properties before, during and after oil shale pyrolysis. Quantitative 2-D, 3-D and 4-D imaging datasets across nm-µm-mm length scales are of great value to better understand, predict and model dynamics of pore structure change and hydrocarbon transport and production during oil shale pyrolysis.Open Acces

Geological parameterisation of petroleum reservoir models for improved uncertainty quantification

As uncertainty can never be removed from reservoir forecasts, the accurate quantification of uncertainty is the only appropriate method to make reservoir predictions. Bayes’ Theorem defines a framework by which the uncertainty in a reservoir can be ascertained by updating prior definitions of uncertainty with the mismatch between our simulation models and the measured production data. In the simplest version of the Bayesian methodology we assume that a realistic representation our field exists as a particular combination of model parameters from a set of uniform prior ranges. All models are believed to be initially equally likely, but are updated to new values of uncertainty based on the misfit between the historical and production data. Furthermore, most effort in reservoir uncertainty quantification and automated history matching has been applied to non-geological model parameters, preferring to leave the geological aspects of the reservoir static. While such an approach is the easiest to apply, the reality is that the majority of the reservoir uncertainty is sourced from the geological aspects of the reservoir, therefore geological parameters should be included in the prior and those priors should be conditioned to include the full amount of geological knowledge so as to remove combinations that are not possible in nature. This thesis develops methods of geological parameterisation to capture geological features and assess the impact of geologically derived non-uniform prior definitions and the choice of modelling method/interpretation on the quantification of uncertainty. A number of case studies are developed, using synthetic models and a real field data set, that show the inclusion of geological prior data reduces the amount of quantified uncertainty and improves the performance of sampling. The framework allows the inclusion of any data type, to reflect the variety of geological information sources. ii Errors in the interpretation of the geology and/or the choice of an appropriate modelling method have an impact on the quantified uncertainty. In the cases developed in this thesis all models were able to produce good history matches, but the differences in the models lead to differences in the amount of quantified uncertainty. The result is that each quantification would lead to different development decisions and that the a combination of several models may be required when a single modelling approach cannot be defined. The overall conclusion to the work is that geological prior data should be used in uncertainty quantification to reduce the uncertainty in forecasts by preventing bias from non-realistic models

Transdimensional change-point modeling as a tool to investigate uncertainty in applied geophysical inference: An example using borehole geophysical logs

International audienceRecently developed methods for inferring abrupt changes in data series enable such change points in time or space to be identified, and also allow us to estimate noise levels of the observed data. The inferred probability distributions of these parameters provide insights into the capacity of the observed data to constrain the geophysical analysis and hence the magnitudes, and likely sources, of uncertainty. We carry out a change-point analysis of sections of four borehole geophysical logs (density, neutron absorption, sonic interval time, and electrical resistivity) using transdimensional Bayesian Markov chain Monte Carlo to sample a model parameter space. The output is an ensemble of values which approximate the posterior distribution of model parameters. We compare the modeled change points, borehole log parameters, and the variance of the noise distribution of each log with the observed lithology classes down the borehole to make an appraisal of the uncertainty characteristics inherent in the data. Our two examples, one with well-defined lithology changes and one with more subtle contrasts, show quantitatively the nature of the lithology contrasts for which the geophysical borehole log data will produce a detectable response in terms of inferred change points. We highlight the different components of variation in the observed data: due to the geologic process (dominant lithology changes) that we hope to be able to infer, geologic noise due to variability within each lithology, and analytical noise due to the measurement process. This inference process will be a practical addition to the analytical tool box for borehole and other geophysical data series. It reveals the level of uncertainties in the relationships between the data and the observed lithologies and would be of great use in planning and interpreting the results of subsequent routine processing