SPE Forum: Enhanced Oil Recovery – The Future is Now! 18 - 23 October 2015 | Cancun, Mexico Managed Pressure Drilling—Niche Technology or the Future of Drilling? Water Management: Is an Ounce of Prevention Worth a Pound of Cure? 22–26 Oct 2012 | Carlsbad, California, USA Excellence in Fracture Stimulation–The Present and Future of Affordable Energy 20–25 May 2012 | Xi'an, China CO2 Geological Storage: Will we be ready in time? Getting to Zero–An incident Free Workplace: How do we get there?
Agbor, Fritz Ako (University of Western Cape) | Mhlambi, Sanelisiwe (University of Western Cape) | Teumahji, Nimuno Achu (Schlumberger Limited) | Sonibare, Wasiu Adedayo (Schlumberger Limited) | Van Bever Donker, Johannes Marinus (University of Western Cape) | Chatterjee, Tapas Kumar (University of Western Cape)
Despite the undergoing exploration and research for hydrocarbons during the recent decades, the hydrocarbon potentials of existing source rock(s) in the Pletmos basin still remain enigmatic. The basin has undergone rifting and transforms processes during its evolution in a manner that its present-day architecture and geodynamic evolution can only be better understood through the application of a multidisciplinary and multi-scale geo-modelling procedure.
In the study, thermal modelling and reconstruction of burial history of the source rocks in the southern depocenter of the Pletmos Basin has been investigated through an integration of data and methods.
Through geohistory Modelling, an integration of the acquired multidisciplinary dataset allowed us to reconstruct the burial history, basement subsidence, vertical fluid flow, and the changes in rock properties (i.e. porosity, permeability, pressure and fluid flow rate) both in time and depth, as well as established a reliable tectonostratigraphic framework of the Mesozoic sedimentary infill. Then based on the reconstructed burial history, thermal history was reconstructed by modifying the paleoheat flux to minimize variances, and comparing between measured borehole and predicted vitrinite reflectance and Tmax (thermal indicator) values. These enable us to achieve an improved understanding of the subsurface controlling processes that might have led to the sedimentary infill and resulted to the heat-flow distribution and present-day thermal maturity of the source rocks in the Basin. The approach gives us the opportunity to considered the geodynamic evolution events from Mesozoic (Upper Jurassic) rifting to Cenozoic (including major uplifts, erosion and subsidence, and the Shona Buvet hot spots). Here we present some selected results, from the burial and thermal history modelling reconstructions of the sedimentary geothermal evolution and thermal maturity levels of the source rocks at selected well locations within the area. Likewise, this study has provided supplementary information that aids towards understanding the Petroleum System(s) of the Basin.
Germany and China have indicated that target dates are being calculated. Paris recently announced a ban of its own (by 2030), while Austria, Denmark, Ireland, Japan, the Netherlands, Portugal, Korea, and Spain have set official targets for electric car sales. The US doesn't have a federal policy, but at least eight states have now set their goals. If we take these mandates at face value, it might seem that the end of the oil industry is near, with oil rigs and refineries being scrapped, gas stations shutting down, and an all-electric, all-renewable future arriving sooner rather than later. In practice, the transition will happen one car sale at a time, led by what consumers want and what industry can produce profitably.
Creation of Strategic Petroleum Reserves (SPRs) is one of the contingency measures adopted by Government of India (GoI) to meet energy security mandate. SPRs are oil stocks stored in large underground storage facilities with intrinsic advantages on economic, environmental and strategic safety considerations. The inventories are used to mitigate economic supply disruptions. The crude oil storage alternatives include Salt and Rock caverns, while for natural gas storage, depleted reservoirs, deep aquifers and salt caverns are used. Though salt caverns are the cheapest storage alternative, adoption of storage technology involves availability of suitable geological setting viz. salt formations or competent rock formations with supplementing groundwater regime.
Under Phase I storage program, GoI, through a SPV - Indian Strategic Petroleum Reserves Ltd. (ISPRL), under Ministry of Petroleum & Natural Gas, has created SPRs at three locations viz. Vishakhapatnam, Mangalore and Padur for a total storage capacity of 5.33 MMT, involving storage of crude oil in underground unlined rock caverns. Engineers India Ltd (EIL) has been the Project Management Consultant for these coveted projects. The storage installation at Vishakhapatnam and Manglore has already been commissioned in 2015 &2016, the installation at Padur is being commissioned by Q3 of 2017.
Apropos Integrated Energy Policy of India; DPRs for the Phase II storage program have been completed and the proposition is under consideration for establishment of additional storage capacity of 10.0 MMT comprising of 4.4 MMT & 5.6 MMT storage capacities at two additional locations, namely Chandikhol, Odisha and Bikaner, Rajasthan entailing storage of crude oil in underground rock caverns and salt caverns respectively.
The present paper outlines the storage technologies, concept of SPRs, emergency stock holding pattern and experiences gained during implementation of these projects of national importance and the lessons for emerging oil dependent economies to establish similar storage inventories.
Ferreira, Joana (University of Lisbon, Faculty of Sciences, Department of Geology) | Azerêdo, Ana C. (University of Lisbon, Faculty of Sciences, Department of Geology and Instituto Dom Luiz) | Bizarro, Paulo (Partex Oil & Gas) | Ribeiro, Maria Teresa (Partex Oil & Gas) | Sousa, Ana (Partex Oil & Gas)
Characterizing highly heterogeneous carbonate reservoirs requires the integration and detailed analysis of petrophysics, facies, diagenesis, geometry, depositional environments and lateral and vertical variability. This is often challenging to conceptual models at oil-field scale, as this thorough analysis is hard to fully reproduce at reservoir-scale models. In order to improve skills and interpretations on both approaches, we addressed a case study from a Middle Jurassic outcrop of Portugal as an analogue for a carbonate reservoir.
The outcrop exhibits three barrier shoreface lithofacies: L1 - oolitic and bio-intraclastic grainstones (divided into: L1a- with planar stratification or unstructured; L1b - with diverse cross-stratification styles); L2 - coarser grained grainstones/rudstones; and L3- coral/algal biostromes. Outcrop analysis was combined with petrographic/diagenetic studies of rock samples. Regarding petrophysical properties, three methods were used to determine the porosity: thin-section impregnation with blue-dyed epoxy resin, rock-slab water saturation and, for a few samples, plug measurements in a Helium gas expansion porosimeter. The plugs were also used to acquire permeability values using a digital gas permeameter.
The results show that the outcrop is a tight reservoir, since most levels have low porosity (~3.5% average) and permeability (mostly <0.1md), though higher values (φ~10-15% and K~160md) occur locally. Most levels are classified as hybrid 1 or diagenetic reservoirs, according to
Normal industry workflows often do not fully consider geological data and conceptual models, and instead rely heavily on geostatistical propagation of well data. The results obtained indicate that there is an improvement in reservoir understanding with an integrated reservoir characterization and modelling process that accounts for actual depositional and diagenetic trends, as well as the distribution of the sedimentary bodies.
The pdf file of this paper is in English.
Mineralogical characterization of mudrocks of the North Lisbon Area, was based on an experimental study including 31 samples collected both from boreholes and outcrops. X-ray diffraction (XRD) was applied to the whole rock fraction to identify the mineral phases present. This technique were specified used to determine the concentrations of clay mineral species as well as feldspar percentages. X-ray fluorescence (XRF) was used to determine apatite and rutile concentrations. Wet geochemical techniques were used to determine the non-clay constituents as quartz, carbonates, pyrite and organic matter. Clay minerals identified in the samples were kaolinite, illite, smectite and mixed-layer illite-smectite and their percentages were determined from less than 2 µm fraction. The mineralogical composition of the samples was recalculated from the data obtained using the laboratory techniques referred to. Furthermore, the distribution of the different mineral phases as a function of the depth in the boreholes profiles were also analysed.
Caracterización mineralógica de lutitas de la Zona Norte de Lisboa, Portugal
Caracterización mineralógica de lutitas de la Zona Norte de Lisboa, se basó en un estudio experimental incluyendo 31 muestras recogidas de perforaciones y afloramientos. La difracción de rayos X (XRD) se aplicó a fracción total de la roca para identificar las fases minerales presentes. Esta técnica se utilizó para determinar las concentraciones de las especies minerales de arcilla, así como los porcentajes de feldespato. La fluorescencia de rayos X (XRF) se utilizó para determinar las concentraciones de apatita y de rutilo. Fueron usadas técnicas geoquímicas por vía húmeda para determinar los constituyentes no arcillosos como cuarzo, carbonatos, pirita y materia orgánica. Los minerales de arcilla identificados en las muestras eran caolinita, ilita, esmectita y interstratificados de ilita-esmectita y sus porcentajes fueron determinados de la fracción de menor de 2 µm. Las composiciones mineralógicas de las muestras fueron recalculadas a partir de los datos obtenidos usando las técnicas de laboratorio anteriores. Además, también se analizó la distribución de las diferentes fases minerales en función de la profundidad en los perfiles de perforaciones.
One million heads of population require at least 1000 megawatts of electricity capacity as a rule of thumb in industrialized economies. Sub-Saharan Africa (SSA) as at 2013 averaged about 0.91 MW per one thousand head of population on this scale. Nigeria is the largest economy in this region, but only attained peak generated power of 5074.7 MW in 2016 giving it a generated power per population (GPP) value of 0.003%. Nigerian economic development is stunted by the perennial abysmal performance on the scale of GPP.
Many studies have reported a seemingly direct proportionality relationship between economic development and available electricity capacity in a clime. Nigeria has plans to increase electricity capacity through natural gas utilization. This energy resource sustainability however, may not be guaranteed from a non-renewable scale.
This paper evaluates the sustainability of electricity capacity targets in Nigeria and the need placed on natural gas keeping in perspective 0.1%, 0.0075% and 0.003% levels of GPP.
The approach adopts a gas turbine (GT) performance modelling leveraging on the basic thermodynamic processes. Specific fuel consumption (SFC) is determined from the operating conditions of a GT. Given the set GPP scenarios, power profiles are evaluated by imposing the electricity demand outlook estimated with base population growth rate of 2.52%. Interaction of the SFC and the power profiles result in the required quantity of natural gas supplied to the GT power stations.
Neglecting reserves replacement and assigning 70% of base electricity demand to natural gas, a GPP of 0.1%, 0.0075% and 0.003% would deplete allotted base reserves at estimated yearly average rates of 30.8, 6.25 and 4.41 bcf/d respectively. This may only be sustainable for just 16, 79 and 112 years in that order.
It is therefore instructive that renewable electricity generation sources be reconsidered in the future energy resource mix projections for genuine economic development in Nigeria.
The main purpose of this study was to carry out the physical and mechanical characterization of dolomitic limestone from “Camadas de Coimbra” Formation with different degrees of weathering. The study begins with a characterization of the geotechnical properties of the intact stones used in this research. Seven tests (sound velocity, porosity, density, uniaxial compressive strength, point load strength, Schmidt rebound hardness and slake-durability) were carried out. The characterization permitted to understand and evaluate the variation of the mechanical and physical properties throughout the weathering processes. The porosity tends to growth according to the rock weathering degree. Its increase corresponds to a decrease of the ultrasonic velocity and rock density. Considering the totality of the specimens tested, moderate correlation coefficient was found between the longitudinal waves propagation and the point load strength values (r = 0.62). For the longitudinal and transversal waves propagation the correlation coefficient was equal to 0.75.
The main purpose of this work is to contribute to the geotechnical knowledge of several weathering degrees of dolomitic limestone belonging to the “Camadas de Coimbra” Formation. The characterisation of the physical and mechanical properties was carried out.
The study area is located in the city of Coimbra (Central Portugal). Log samples were collected in a prospection campaign performed at Polo I of the University of Coimbra. The rock characterisation was carried out through seven laboratory tests: sound velocity, porosity, density, uniaxial compressive strength, point load strength, Schmidt rebound hardness and slake-durability tests.
Correlations were established based on the test results, in order to define and predict the geotechnical behaviour of dolomitic limestone with different degrees of weathering.
Carbonate reservoir characterization is often a complex task, due to the interplay between primary processes (e.g. depositional environments, facies changes) and secondary processes (e.g. burial, diagenesis, faulting and fracturing, cementation). In order to properly characterize and model such a reservoir, it is paramount to unravel the order by which such processes have affected the rock, leading to the present day petrophysical properties.
In the presented case study (onshore dolomitized carbonate reservoir in Central Asia), a multi-step approach was taken for its characterization and modelling. The characterization phase was focused in understanding the key processes and controls on porosity and permeability. From the core and log data, a detailed sedimentologic and diagenetic study was performed, to identify the depositional environments and facies, as well as the pore system geometry, and its impact on fluid flow. Furthermore, several trends on reservoir quality were identified, related to faults, and associated with depositional cyclicity.
From the above work, a reservoir model was built, to support field development planning and associated uncertainties. A structural and stratigraphic framework was built, and Flow Unit Types (FUT) were defined using seismic, cores, thin sections, logs and mercury injection capillary pressure data (MICP). Property modelling was carried out for porosity and permeability, honouring FUT, depositional and diagenetic trends. In particular, two trends were modelled: a fault-related trend, to introduce the impact of diagenetic leaching related to faults (observed in core data); and a cyclicity related trend, to introduce the impact of preferential fluid flow pathways that occur at or near cycle tops. The uncertainty in the reservoir property models was evaluated with different FUT, driven by depositional and diagenetic concepts.
The results indicate that a significant improvement in reservoir understanding can be achieved with the use of an integrated study and model workflow, focusing on the key control factors that affect the pore system and the distribution of permeability. In this way it was possible to recognize spatial trends and capture the relationship between petrophysical properties, pore architecture and sweep efficiency.
Last year, 244 million tonnes per annum (MTPA) of liquefied natural gas (LNG) was transported around the globe. The recent shale gas revolution, coupled with low domestic natural gas prices, has led many operators in the US to consider export of their gas to more lucrative markets in Asia and Europe. More than 25 LNG projects have been proposed in the US, totaling a capacity of more than 200 MTPA. The Federal Energy Regulatory Commission (FERC) has approved five LNG terminals in the US. Most experts believe US LNG export capabilities will be about 10% of domestic production in the coming years, which puts LNG export estimates between 6 and 8 Bscf/D. The question remains, where will all of this gas come from?
The vast amount of increased gas production in the onshore US will come from growth in the shale gas plays. These plays, including the Barnett, Fayetteville, Woodford, Marcellus, Haynesville, Eagle Ford, and others, will be further exploited to supply domestic needs and the new LNG export demand. A typical proposed US LNG train is estimated to output 4.5 MTPA, which requires an input of around 636 MMscf/D. It will take a significant quantity of shale gas wells to deliver enough gas to keep a train at full capacity. This paper addresses the impact that LNG- driven natural gas demand will have on the future development of shale gas plays in the US.
Increased demand on domestic US natural gas supplies will be met with increased development drilling. In order to quantify the impact of LNG exports on the market, this paper considers the number of horizontal shale gas wells needed to supply one LNG train continuously. Shale gas basins around the US were studied to estimate both the number of wells needed to supply a train initially and the number and frequency of future wells that will need to be drilled to maintain the train at full capacity. Current activities, including infrastructure and rig counts, decline trends, economics, and drilling times are included in the analysis.
This paper discusses the impact future increased LNG gas demand will have on the field development plans of shale gas plays and identifies probable future activity levels in shale gas basins due to exploitation activity focused on LNG supply. The feasibility of LNG export from the US is a topic of debate, and this paper will provide context and rationale for the discussions.