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SPE, through its Energy4me programme, will present a free one-day energy education workshop for science teachers (grades 8–12). A variety of free instructional materials will be available to take back to the classroom. Educators will receive comprehensive, objective information about the scientific concepts of energy and its importance while discovering the world of oil and natural gas exploration and production. Energy4me is an energy educational public outreach programme that highlights how energy works in our everyday lives and promote information about career opportunities in petroleum engineering and the upstream professions. SPE’s Energy4me programme values the role teachers and energy professionals play in educating young people about the importance of energy.
Thank you for attending the SPE Workshop. Naturally fractured carbonate reservoirs hold a substantial volume of the world’s petroleum reserves and has a long production history. However, description of reservoir flow mechanism has been uncertain. Also, the existing reservoir surveillance tools are unreliable which results in reactive rather than proactive planning. Although significant strides have been made in computational technology, there is still need to accurately represent fracture properties in dynamic models.
Zhou, Hongjie (Norwegian Geotechnical Institute) | Sharma, Shambhu (Norwegian Geotechnical Institute) | Amodio, Alessandro (Norwegian Geotechnical Institute) | Boylan, Noel (Norwegian Geotechnical Institute) | Gaunt, Peter (Norwegian Geotechnical Institute)
For subsea structures placed on soft seabed comprising fine-grained sediments, geotechnical design may be equally governed by the foundation settlement and stability requirements. For this reason, the soil stress history parameter, i.e. yield stress (σy), becomes as important as the strength parameter, i.e. undrained shear strength (su). Common practice in characterisation of fine-grained sediments focuses more on deriving the su profile than on evaluating the σy profile. More often, the underlying connections between these two important parameters are overlooked in the interpretation process. As a result, the selected design line of σy may be incompatible to that of su. This paper presents a balanced characterisation of fine-grained soils, focusing on interpretation of in-situ su and σy using a coherent and simple framework underpinned by the Stress History and Normalised Soil Engineering Properties (SHANSEP) relationship. Interpretation procedure, performance and advantages of the proposed framework are demonstrated by a real application to an offshore site dominated by fine-grained carbonate sediments.
In this framework, the two SHANSEP parameters, including normally consolidated normalised strength ratio (S) and empirical constant (m), need to be quantified for the site of interest. This is achieved by performing a series of laboratory strength and consolidation tests on undisturbed samples, with the strength tests being performed respectively under in-situ and elevated stress conditions for determining in-situ su and the values of S and m. Once the SHANSEP parameters and the su profile are derived, the σy profile can be calculated. These two profiles can then be refined further by comparing against the measured su and σy at discrete depths respectively from the strength and consolidation tests.
Since this proposed framework allows the user to consider the results from the in-situ and laboratory tests (including both strength and consolidation tests) holistically, more reliable and coherent interpretation of the su and σy profiles can be achieved. In addition, the framework allows for an easy estimation of consolidation-induced strength gain due to the permanent load applied by the subsea structures by simply using the derived σy profile and updating the vertical stress in the parameterised SHANSEP relationship. This may reduce the conservatism in the foundation design and provide optimisation opportunities.
Considerable interest exists for better understanding the gas storage and transport properties for shale gas reservoirs in Australia’s Beetaloo Basin. In these reservoirs, fluid transport through natural and induced fractures may be described by Darcy’s Law, whereas transport in nanopores of the shale organic and inorganic matrix can occur via diffusion (
In this work, a high-precision high-temperature adsorption/diffusion rig was used to characterise methane adsorption and diffusion behaviour on an intact cube-shaped sample of Beetaloo Basin shale from the Amungee C member. The fixed-volume volumetric method was used to measure across a temperature range of 35 to 150°C and a pressure range of 0.6 to 21 MPa. The adsorption was modelled using the Langmuir isotherm, and the diffusion behaviour modelled using the unipore model. The TOC, thermal maturity, mineralogy and pore structure of the shale was characterised.
Pore characterisation indicated the presence of multiple scales of porosity in the shale (micro, meso and macro). The Langmuir isotherm model was applicable to the measured adsorption data indicating that a homogeneous distribution of monolayer adsorption may predominate in the sample. The pore scales and experimental conditions indicate diffusion is the primary transport mechanism occurring in the shale. The unipore diffusion model provided a good fit to measured CH4 uptake data, and alongside the measured diffusion coefficients suggested that transport is primarily governed by the sample mesoporosity. Increases in diffusivity with respect to CH4 pressure were observed, which reflected an established direct correlation observed in shales and coals between diffusion coefficient and adsorbate density.
This study assists in developing an understanding of the relationship between adsorption and diffusion behaviour and reservoir conditions for shales in the highly prospective Beetaloo Basin. The importance of non-Darcy fluid flow behaviour to shale gas production, and the limited availability of physical samples of Beetaloo basin shales underscores the importance of developing relationships that can help to understand diffusion behaviour where existing data are sparse.
Pramudyo, Yuni (ADNOC Onshore) | Al Hosani, Mariam (ADNOC Onshore) | Al Awadhi, Fatima (ADNOC Onshore) | Masoud, Rashad (ADNOC Onshore) | Al Besr, Huda (ADNOC Onshore) | Nachiappan, Ramanathan (ADNOC Onshore) | Al Hosani, Khaled (ADNOC Onshore) | Al Bairaq, Ahmed (ADNOC Onshore) | Al Ameri, Ammar (ADNOC Onshore) | Bertouche, Meriem (Badley Ashton) | Foote, Alexander (Badley Ashton) | Michie, Emma (Badley Geoscience) | Yielding, Graham (Badley Geoscience)
Throughout the UAE and the wider region, several broadly EW orientated structural lineaments are observed on seismic within the Cretaceous successions and are described as strike-slip faults. However, in the studied field, these features have not been readily observed in well data. Instead, networks of fractures and deformation features are present in core and borehole images. A study was carried out in an attempt to calibrate well and seismic data and to understand the relationship between the seismically-resolved faults and the fractures observed on core. This study focuses on a dataset from the northeast part of the field, which includes BHI images, cores, full 3D CT scans and conventional logs in four penetrations, three of which are horizontal, drilled through the faults; as well as 3D seismic data and relevant derived horizons and fault polygon interpretations.
Ni, Guangyuan (Northeast Petroleum University) | Wang, Zhihua (Northeast Petroleum University) | Yang, Heng (Oil Recovery Plant No. 6, PetroChina Daqing Oilfield Company Limited) | Li, Jiexun (Intercontinental Strait Energy Investment Beijing Company Limited) | Zhao, Xinming (Oil Production Technology Institute, PetroChina Dagang Oilfield Company) | Liu, Yang (Northeast Petroleum University)
The paraffin crystals can aggregate and precipitate when the oil temperature declines below the wax appearance temperature (WAT) of the waxy crude oil. However, the aggregation behaviour of paraffin crystals during the process of crude oil production and transportation is not well revealed. This study concentrates on using fractal dimensional analysis to elucidate the aggregation behaviour of paraffin crystals in shearing fields. A set of microscopic experiments was recently performed to capture the basic information of the paraffin crystal images in different conditions. A methodology for characterizing paraffin crystal aggregation was then developed, and the blanket algorithm was introduced to compute the fractal dimension of aggregated paraffin crystals. The results indicate that the aggregation behaviour of paraffin crystals is closely related to temperature and shearing experienced by the waxy crude oil. The aggregation behaviour would be intensified with the reduction of temperature and the decrease of shearing effect, and it appears to be a wider fractal dimension distribution at lower temperature when the same shear rate range is employed. The lower fractal dimensions are at high temperature and strong shear action, the weaker nonlinear characteristics of paraffin crystals aggregation structure are, and thus the potential paraffin deposition would be inhibited during waxy crude oil production and transportation. The methodology developed in this study is beneficial to optimize the flow assurance operations in single-phase and multiphase pipeline transportation for waxy crude oils, and the results are expected to lead to a better understanding of paraffin crystallization and deposition mechanism.
The development and management of naturally fractured reservoirs (NFRs) is a challenging task for asset teams due to the complexity of these reservoirs. The challenges are observed from the initial exploration phase and continue up to the field development stage. Placing production and injection wells in NFRs pose serious challenges. In most cases, highly permeable fractures are encountered during drilling leading to substantial loss of drilling fluids and extensive use of loss circulation materials. Thus, asset teams need to proactively predict location of these highly conductive fractures since they act as channels for rapid water or gas movement leading to early breakthrough and poor volumetric sweep efficiency.
Tsuji, Masakuni (Shimizu Corporation) | Aoyagi, Kazuhei (Japan Atomic Energy Agency) | Nakashima, Hitoshi (Shimizu Corporation) | Okihara, Mitsunobu (Shimizu Corporation) | Sato, Toshinori (Japan Atomic Energy Agency)
This paper shows an overall result for a 3-year study on the characterisation of the colloidal silica grout (CSG) under saline groundwater. The CSG is suitable for sealing narrow fractures and has been studied and applied for grouting in the deep undergrounds to satisfy the strict inflow requirements. However, this grout is known to be sensitive to the salinity of groundwater because of its gelling mechanism with an inorganic salt.
In Japan, the coastal region has been discussed to be a more suitable region for the geological disposal of high-level waste. The groundwater in this region or the fossil water observed in the deep underground may have a salinity. The purpose of this research is to enhance the existing rock grouting technology, especially for the CSG under the saline groundwater. As a first step, we performed the survey of the latest grouting technology of CSG, including a grouting workshop in Finland with Nordic authorities. This survey was aimed to identify the most significant challenges to developing the grouting methodologies for CSG under salty groundwater.
Along with the initial survey, this project focused on obtaining the various characteristics of CSG by the laboratory tests. We developed a feasible mixing methodology using an acidic pH adjuster that prevents the rapid reaction with the salt in the groundwater, and we have obtained the CSG’s basic properties, and its long-term characteristics impacted by the salty mixing water or submerged by saline water up to 250 days. Moreover, we proposed a theory for the penetration of CSG under saline water, and performed the injection tests in the laboratory, with use of different CSG and the various type of surrounding groundwater, in order to verify this theory by understanding the impact of salinity to the grout penetration property. Details are shown in another paper in this symposium, see Jari et al. .
Our findings in the characterisation of CSG under saline water for the basic properties and the penetration properties were recognised to attain some progress in the development of the grouting technology, which was one of the results in the discussion in the second workshop in the last year. It was also pointed out necessary to keep studying in this field for its further development, such as the development of the penetration theory by further experiments targeting the testing at the site.
The continuous study in this field by periodically exchanging the latest technologies with a hybrid approach should be necessary for further development of grouting technology. The developed grouting methodology in CSG will robustly and effectively decrease the ingress of water from the narrow fractures filled with fossil water in the disposal facilities or seawater in submarine tunnels.
Ajayi, Oluwaseun E. (Saka Matemilola FIRST E&P) | Lawal, Kazeem A. (Saka Matemilola FIRST E&P) | Ukaonu, Cyril E. (Saka Matemilola FIRST E&P) | Alabi, Tunde (Saka Matemilola FIRST E&P) | Okoh, Oluchukwu (Nigerian Petroleum Development Company) | Igbokwe, Obianuju (Schlumberger)
Drilling fluids are vital elements in the safe, efficient and effective construction of wells. Their key functions include transporting drill cuttings to the surface, cooling and lubrication of drill string, cleaning build-up deposits on drill bits and tools, as well as stabilisation of the borehole and pressure control. Because they are often a complex mixture of different solids and fluids, the rheology of drilling fluids is usually complicated. As a result, they typically exhibit non-Newtonian flow behaviours. While the traditional practice is to use critical velocity to describe the flow regimes of drilling fluids by discriminating between laminar and turbulent conditions, this paper explores the applicability of Reynolds numlber (
Models to estimate
The applicability of the proposed models and ideas are not limited to drilling fluid hydraulics. The findings are relevant in other areas of transporting non-Newtonian fluids such as polymer for enhanced-oil recovery and multiphase mixtures such as emulsions, waxy crudes and general pipeline transport. Additionally, the principles and insights should be of interest to other industries such as food processing and chemical manufacturing.
A wide range of technologies and workflows is available to assist in optimising the horizontal drilling process in real time and provide thorough formation evaluation analysis while landing and steering the wells. Traditionally, advanced surface fluid logging (ASFL) has not been relied upon as one of these methods; however, developments in the real-time fluid analysis provided by this technology were utilised to achieve a better understanding of fluid distribution while supporting critical decisions landing the horizontal section of a production well. Understanding the fluid complexity in a Danish North Sea chalk field was the main key in optimising the placement of the well. Initially, it was predicted that due to the migration of the gas cap, the fluids in the oil rim target would have undergone a significant compositional change from the virgin fluid. Placement of the well at the top of the expected oil column was critical to intercept as much of the oil as possible while mitigating against premature water/gas breakthrough and maintaining a minimum standoff from the gas-oil contact (GOC).