Assessment of Unconventional Resources Opportunities in the Middle East Tethyan Petroleum System in a Transfer Learning Context

Decision making in new fields with little data available relies heavily on physics-based simulation models. However, due to a lack of full understanding of the physical processes governing flow in the unconventional resources, data-driven modeling has emerged as an alternative and complimentary tool to create recovery forecasts that honor the available data. Transfer Learning provides an opportunity to start early-stage analysis of the asset before adequate data becomes available. New challenges in the energy industry as well as shifting dynamics in both domestic and global supply and demand has encouraged some of the petroleum exporting countries in the Middle East to strategize the development of unconventional resources. In this research we have developed a data-driven Transfer Learning framework that allows the basin-wide assessment of new shale gas and tight oil prospects. The proposed Transfer Learning method is developed on real-world data from several thousand horizontal multistage wells in the Eagle Ford super-basin in South Texas. In this method we have integrated reservoir engineering domain expertise in the data pre-processing and feature generation steps. We have also considered the temporal and spatial balancing of the training data to assure that the predictive models honor the real practice of unconventional field development. Our full cycle Transfer Learning workflow consists of dimensionality reduction and unsupervised clustering, supervised learning, and hyperparameter fine-tuning. This workflow enables reservoir engineers to experiment with multiple hypothetical scenarios and observe the impact of additional data in the learning process. We use the developed workflow to examine the performance of a data-driven model of the Eagle Ford Basin on potential plays in the Middle East. Existence of all liquid types of oil, condensate and dry gas in the Eagle Ford has resulted in training a model flexible enough to be tested on various types of assets in a new location. We first present the successful deployment of our model within the Eagle Ford. Next, we use the information from major formations such as Tuwaiq Mountain and Hanifa and show the value of a pre-existing model from a fully-developed shale play on achieving acceptable accuracies with minimal information available in a new field. Our model is developed by data types with relatively low resolution that minimizes overfitting effects and allows generalization to different geologies with basin-wide accuracy. This approach allows conducting accelerated assessment of various sections of a large asset to enhance field development planning processes. This is a first example of such an effort on a basin scale that examines the effectiveness of Transfer Learning on some of the major unconventional plays in the Middle East region. This workflow allows investigating the relationship among geologic and petrophysical variables, drilling and completion parameters, and productivity of a large group of wells in a new asset.

Future Proofing the Development of Unconventional Resources in UAE

The growth of USA shale oil and gas production over the last decade has been nothing short of phenomenal. In 2012 shale gas comprised 39% of US natural gas output, and by 2040, nearly 80% of total gas production is anticipated to come from unconventional resources. In April 2021, in the USA alone, gas production from major unconventional plays reached 83.0 BCFD and oil production was 7.6 MMBD. Driven by rising gas demand and advances in geosciences, drilling and completion technology (hydraulically fractured horizontal wells), unconventional plays have become eminent in the global energy supply, both for value and volume. The development of unconventional resources in North America was aided by governmental positive policies and taxes preferences, the readily available infrastructure, a vast service sector, advanced technologies and expertise, and general understanding of sweet spots due to numerous well penetrations. Following the above accomplishments: exploration, development, and production success in North America, particularly in the USA unconventional basins, several Majors and Independents have been trying to expand the opportunities outside of North America and other countries such as UAE, Oman and Saudi Arabia have been booking significant unconventional resources. For these reasons, the USA and Canada represent the ‘reference benchmark’ by which countries similarly endowed with shale resources can be evaluated. Abu Dhabi recently announced, in 2019 and 2020, discoveries of 160 TCF of unconventional gas, an estimated 22 billion STB of recoverable unconventional oil resources, both located onshore. These finds have pushed the UAE to the sixth position globally in terms of hydrocarbon reserves, from seventh, according to data listed by the US Energy Information Administration (EIA). Developing these resources are an integral part of ADNOC 2030 strategy of "Monetize our hydrocarbon resources" and becoming gas self-sufficient by 2030. North America achievements in unconventional resources development has triggered other countries to evaluate their unconventional resources. This has come with mixed results: failures in Ukraine, Poland and successes in Argentina. UAE has world class unconventional resource base which development raises the challenges of what practices worth replicating (PWR) need to be adopted by UAE and in turn ADNOC. Some lessons learned, thus practices worth replicating (PWR) can be tailored and adopted from the success of unconventional resources development in North America, will be described in this paper as a benchmark for progressing unconventional resources development in UAE.

Unconventional hydrocarbon resources: geological statistics, petrophysical characterization, and field development strategies

Hydrocarbons exist in abundant quantity beneath the earth's surface. These hydrocarbons are generally classified as conventional and unconventional hydrocarbons depending upon their nature, geology, and exploitation procedure. Since the conventional hydrocarbons are under the depletion phase, the unconventional hydrocarbons have been a major candidate for current and future hydrocarbon production. Additionally, investment and research have increased significantly for its exploitation. Having the shift toward unconventional hydrocarbons, this study reviews in depth the technical aspects of unconventional hydrocarbons. This review brings together all the important aspects of unconventional reservoirs in single literature. This review at first highlights the worldwide unconventional hydrocarbon resources, their technical concept, distribution, and future supplies. A portion of this study also discusses the resources of progressive unconventional hydrocarbon candidates. Apart from this, this review also highlights the geological aspects of different unconventional hydrocarbon resources including tight, shale, and coalbed methane. The petrophysical behavior of such assists including the response to well logs and the discussion of improved correlation for petrophysical analysis is a significant part of this detailed study. The variation in geology and petrophysics of unconventional resources with conventional resources are also presented. In addition, the latest technologies for producing unconventional hydrocarbons ranging from fractured wells to different fluid injections are discussed in this study. In the end, the latest machine learning and optimization techniques have been discussed that aids in the optimized field development planning of unconventional reservoirs.

Rare Earth Phosphates in the Kerch Caviar Ironstones

—The mineralogy and contents of major and trace elements (including REE+Y) in bulk samples and separate size fractions of caviar-like ironstones from the Kamysh-Burun deposit (Kerch iron province) are studied to estimate the contributions of different REE+Y species to the total budget. The analyzed ore samples contain MREE adsorbed on Fe3+-(oxy)hydroxides, as well as LREE authigenic phosphates. The predominant rhabdophane-type (Ce(PO4)⋅nH2O) phases are enriched in La, Pr, Nd, and Ca, depleted in Ce, and free from Th. The REE carriers belong to solid solution series of two main types: LREE(PO4)·nH2O – (Ca,Ce,Th)(PO4)·H2O (rhabdophane-like phase and brockite) or LREE(PO4)·nH2O – (Ca,U,Fe3+)((PO4),(SO4))·2H2O (rhabdophane-like phase and tristramite). REE phosphates occur most often in the ≤ 0.25 mm fractions of ironstones, where average and maximum ΣREE contents (Xav = 606–1954 ppm; Xmax = 769–3011 ppm) are comparable with the respective amounts in the Chinese industrial clay-type REE deposits. The Kerch ores are commercially attractive unconventional resources of highly demanded Pr and Nd: they can be extracted at relatively low costs, due to high Pr/Ce and Nd/Ce ratios, while low Th and U reduce the environmental risks from stockpiled wastes.

Nanocomposite and Nanofluids: Towards a Sustainable Carbon Capture, Utilization, and Storage

Large volumes of unconventional fossil resource are untapped because of the capillary forces, which kept the oil stranded underground. Furthermore, with the increasing demand for sustainable energy and the rising attention geared towards environment protection, there is a vital need to develop materials that bridge the gap between the fossil and renewable resources effectively. An intensive attention has been given to nanomaterials, which from their native features could increase either the energy storage or improve the recovery of fossil energy. The present chapter, therefore, presents the recent advancements of nanotechnology towards the production of unconventional resources and renewable energy. The chapter focuses primarily on nanomaterials applications for both fossils and renewable energies. The chapter is not intended to be an exhaustive representation of nanomaterials, rather it aims at broadening the knowledge on functional nanomaterials for possible engineering applications.

Effect of permeability and fractures on oil mobilization of unconventional resources during CO2 EOR using nuclear magnetic resonance

CO2 EOR (enhanced oil recovery) will be one of main technologies of enhanced unconventional resources recovery. Understanding effect of permeability and fractures on the oil mobilization of unconventional resources, i.e. tight oil, is crucial during CO2 EOR process. Exposure experiments based on nuclear magnetic resonance (NMR) were used to study the interaction between CO2 and tight oil reservoirs in Chang 8 layer of Ordos Basin at 40 °C and 12 MPa. Effect of permeability and fractures on oil mobilization of exposure experiments were investigated for the different exposure time. The oil was mobilized from matrix to the surface of matrix and the oil recovery increased as the exposure time increased. The final oil recovery increased as the core permeability increased in these exposure experiments. Exposure area increased to 1.75 times by fractures resulting in that oil was mobilized faster in the initial stage of exposure experiment and the final oil recovery increased to 1.19 times from 28.8 to 34.2%. This study shows the quantitative results of effect of permeability and fractures on oil mobilization of unconventional resources during CO2 EOR, which will support CO2 EOR design in Chang 8 layer of Ordos Basin.