Core Scale FEM Modeling of Thermochemical Fracturing on Cement Cube Samples

2021 ◽  
Author(s):  
Zeeshan Tariq ◽  
Ayman AlNakhli ◽  
Abdulazeez Abdulraheem ◽  
Mohamed Mahmoud
Keyword(s):  
Sensitivity Analysis ◽  
Global Economy ◽  
Oil And Gas ◽  
Peak Pressure ◽  
Exothermic Reaction ◽  
Cohesive Zone Modeling ◽  
Fem Modeling ◽  
Breakdown Pressure ◽  
Multiple Fractures ◽  
Micro Cracks

Abstract Brownfields and depleting conventional resources of fossil fuel energy are not enough to fulfill the tremendously increasing energy demands around the globe. Unconventional oil and gas resources are creating a huge impact on the enhancement of the global economy. Tight rocks are usually located in deep and high-strength formations. In this study, numerical simulation results on a new thermochemical fracturing approach is presented. The new fracturing approach was implemented to reduce the breakdown pressure of the unconventional tight formations. The hydraulic fracturing experiments presented in this study were carried out on ultra-tight cement block samples. The permeability of the block samples was less than 0.005mD. Thermochemical fracturing was carried out by a thermochemical fluids that caused a rapid exothermic reaction which resulted in the instantaneous generation of heat and pressure. Different salts of nitrogen such as sodium nitrite and ammonium chloride were used as a thermochemical fluid. The instantaneous generation of the heat and pressure caused the creation of micro-cracks. The fracturing results revealed that the novel thermochemical fracturing was able to reduce the breakdown pressure in ultra-tight cement from 1095 psi to 705 psi. The reference breakdown pressure was recorded from the conventional fracturing technique. A finite element (FEM) analysis was conducted using commercial software ABAQUS. In FEM, two approaches were used to model the thermochemical fractures namely, cohesive zone modeling (CZM) and concrete damage plasticity models (CDP). The sensitivity analysis of peak pressure and time to reach the peak pressure is also presented in this study. The sensitivity analysis can help in better designing thermochemical fluids that could lead to the maximum generation of micro-cracks and multiple fractures.

The Central Asian Economies in the Twenty-First Century

2019 ◽  
Author(s):  
Richard Pomfret
Keyword(s):  
Migrant Workers ◽  
Global Economy ◽  
Oil And Gas ◽  
The United States ◽  
Kyrgyz Republic ◽  
The European Union ◽  
Central Asian ◽  
Asian Economies ◽  
Belt And Road ◽  
External Powers

This book analyzes the Central Asian economies of Kazakhstan, the Kyrgyz Republic, Tajikistan, Turkmenistan, and Uzbekistan, from their buffeting by the commodity boom of the early 2000s to its collapse in 2014. The book examines the countries' relations with external powers and the possibilities for development offered by infrastructure projects as well as rail links between China and Europe. The transition of these nations from centrally planned to market-based economic systems was essentially complete by the early 2000s, when the region experienced a massive increase in world prices for energy and mineral exports. This raised incomes in the main oil and gas exporters, Kazakhstan and Turkmenistan; brought more benefits to the most populous country, Uzbekistan; and left the poorest countries, the Kyrgyz Republic and Tajikistan, dependent on remittances from migrant workers in oil-rich Russia and Kazakhstan. The book considers the enhanced role of the Central Asian nations in the global economy and their varied ties to China, the European Union, Russia, and the United States. With improved infrastructure and connectivity between China and Europe (reflected in regular rail freight services since 2011 and China's announcement of its Belt and Road Initiative in 2013), relaxation of UN sanctions against Iran in 2016, and the change in Uzbekistan's presidency in late 2016, a window of opportunity appears to have opened for Central Asian countries to achieve more sustainable economic futures.

Ranking and Sensitivity Analysis of Key Factors for Successful Project Management Performance: An Application of AHP for Oil and Gas Sector

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Farhaj Ishtiaq ◽  
Mirza Jahanzaib
Keyword(s):  
Sensitivity Analysis ◽  
Project Management ◽  
Analytical Hierarchy Process ◽  
Oil And Gas ◽  
Planning Process ◽  
Project Planning ◽  
Key Factors ◽  
Management Performance ◽  
Hierarchy Process ◽  
Oil And Gas Sector

<p>Complexities faced by oil and gas projects due to uncertainty and risk, demand the implementation of project management techniques for their successful completion. Therefore, this is made by using analytical hierarchy process, to identify and prioritize the key factors for successful project management performance of oil and gas projects. These factors are categorized into three groups which include attributes of project staff, project planning process and assessment of project quality. Using expert choice, a hierarchy is developed followed by pairwise comparison based upon data collection from industrial experts of oil and gas sector. Results of analytical hierarchy process (AHP) concluded that, project completion within estimated time and budget, clarity of objectives and involvement of top management are most crucial elements for improvement in project management performance of oil and gas projects. Whereas sensitivity analysis being carried out according to three different scenarios highlighted factors according to their relative importance.</p>

The Role of Oil and Gas in the Economic Development of the Global Economy

2018 ◽  
Author(s):  
Paul Stevens
Keyword(s):  
Economic Development ◽  
Global Economy ◽  
Oil And Gas ◽  
Primary Energy ◽  
Oil And Gas Producers ◽  
The Future ◽  
History Of ◽  
Factor Inputs ◽  
The Impact

This chapter is concerned with the role of oil and gas in the economic development of the global economy. It focuses on the context in which established and newer oil and gas producers in developing countries must frame their policies to optimize the benefits of such resources. It outlines a history of the issue over the last twenty-five years. It considers oil and gas as factor inputs, their role in global trade, the role of oil prices in the macroeconomy and the impact of the geopolitics of oil and gas. It then considers various conventional views of the future of oil and gas in the primary energy mix. Finally, it challenges the drivers behind these conventional views of the future with an emphasis on why they may prove to be different from what is expected and how this may change the context in which producers must frame their policy responses.

Field Implementation of RBI for Jacket Structures

2003 ◽  
Author(s):  
Michael H. Faber ◽  
Daniel Straub ◽  
John D. So̸rensen ◽  
Jesper Tychsen
Keyword(s):  
Sensitivity Analysis ◽  
Data Base ◽  
Stress Ratio ◽  
Oil And Gas ◽  
Inspection Planning ◽  
The North ◽  
Large Numbers ◽  
Structural Details ◽  
Jacket Structures ◽  
The North Sea

The present paper first gives a brief outline of the simplified and generic approach to reliability and risk based inspection planning and thereafter sets focus on a recent application of the methodology for planning of in-service NDT inspections of the fixed offshore steel jacket structures in the DUC concession area in the Danish part of the North-Sea. The platforms are operated by Maersk Oil and Gas on behalf of DUC partners A.P. Mo̸ller, Shell and Texaco. The study includes a sensitivity analysis performed for the identification of relevant generic parameters such as the bending to membrane stress ratio, the design fatigue life and the material thickness. Based on the results of the sensitivity analysis a significant number of inspection plans were computed for fixed generic parameters (pre-defined generic plans) and a data-base named iPlan was developed from which inspection plans may be obtained by interpolation between the pre-defined generic plans. The iPlan data-base facilitates the straightforward production of large numbers of inspection plans for structural details subject to fatigue deterioration. In the paper the application of the generic inspection plan database iPlan is finally illustrated on an example.

A methodology for optimizing modeling configuration in the numerical modeling of oil concentrations in underwater blowouts: a North Sea case study

2021 ◽  
Author(s):  
Andrés Martínez
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Modeling ◽  
High Resolution ◽  
North Sea ◽  
Oil And Gas ◽  
Data Bases ◽  
Lagrangian Trajectory ◽  
Number Of Particles

&lt;p&gt;&lt;strong&gt;A METHODOLOGY FOR OPTIMIZING MODELING CONFIGURATION IN THE NUMERICAL MODELING OF OIL CONCENTRATIONS IN UNDERWATER BLOWOUTS: A NORTH SEA CASE STUDY&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Andr&amp;#233;s Mart&amp;#237;nez&lt;sup&gt;a,*&lt;/sup&gt;, Ana J. Abascal&lt;sup&gt;a&lt;/sup&gt;, Andr&amp;#233;s Garc&amp;#237;a&lt;sup&gt;a&lt;/sup&gt;, Beatriz P&amp;#233;rez-D&amp;#237;az&lt;sup&gt;a&lt;/sup&gt;, Germ&amp;#225;n Arag&amp;#243;n&lt;sup&gt;a&lt;/sup&gt;, Ra&amp;#250;l Medina&lt;sup&gt;a&lt;/sup&gt;&lt;/p&gt;&lt;p&gt;&lt;sup&gt;a&lt;/sup&gt;IHCantabria - Instituto de Hidr&amp;#225;ulica Ambiental de la Universidad de Cantabria, Avda. Isabel Torres, 15, 39011 Santander, Spain&lt;/p&gt;&lt;p&gt;&lt;sup&gt;* &lt;/sup&gt;Corresponding author: [email protected]&lt;/p&gt;&lt;p&gt;Underwater oil and gas blowouts are not easy to repair. It may take months before the well is finally capped, releasing large amounts of oil into the marine environment. In addition, persistent oils (crude oil, fuel oil, etc.) break up and dissipate slowly, so they often reach the shore before the cleanup is completed, affecting vasts extension of seas-oceans, just as posing a major threat to marine organisms.&lt;/p&gt;&lt;p&gt;On account of the above, numerical modeling of underwater blowouts demands great computing power. High-resolution, long-term data bases of wind-ocean currents are needed to be able to properly model the trajectory of the spill at both regional (open sea) and local level (coastline), just as to account for temporal variability. Moreover, a large number of particles, just as a high-resolution grid, are unavoidable in order to ensure accurate modeling of oil concentrations, of utmost importance in risk assessment, so that threshold concentrations can be established (threshold concentrations tell you what level of exposure to a compound could harm marine organisms).&lt;/p&gt;&lt;p&gt;In this study, an innovative methodology has been accomplished for the purpose of optimizing modeling configuration: number of particles and grid resolution, in the modeling of an underwater blowout, with a view to accurately represent oil concentrations, especially when threshold concentrations are considered. In doing so, statistical analyses (dimensionality reduction and clustering techniques), just as numerical modeling, have been applied.&lt;/p&gt;&lt;p&gt;It is composed of the following partial steps: (i) classification of i representative clusters of forcing patterns (based on PCA and K-means algorithms) from long-term wind-ocean current hindcast data bases, so that forcing variability in the study area is accounted for; (ii) definition of j modeling scenarios, based on key blowout parameters (oil type, flow rate, etc.) and modeling configuration (number of particles and grid resolution); (iii) Lagrangian trajectory modeling of the combination of the i clusters of forcing patterns and the j modeling scenarios; (iv) sensitivity analysis of the Lagrangian trajectory model output: oil concentrations, &amp;#160;to modeling configuration; (v) finally, as a result, the optimal modeling configuration, given a certain underwater blowout (its key parameters), is provided.&lt;/p&gt;&lt;p&gt;It has been applied to a hypothetical underwater blowout in the North Sea, one of the world&amp;#8217;s most active seas in terms of offshore oil and gas exploration and production. A 5,000 cubic meter per day-flow rate oil spill, flowing from the well over a 15-day period, has been modeled (assuming a 31-day period of subsequent drift for a 46-day modeling). Moreover, threshold concentrations of 0.1, 0.25, 1 and 10 grams per square meter have been applied in the sensitivity analysis. The findings of this study stress the importance of modeling configuration in accurate modeling of oil concentrations, in particular if lower threshold concentrations are considered.&lt;/p&gt;

Development Prospect of Unconventional Oil and Gas Resources

2013 ◽  
Vol 421 ◽  
pp. 917-921
Author(s):  
De Xun Liu ◽  
Shu Heng Tang ◽  
Hong Yan Wang ◽  
Qun Zhao
Keyword(s):  
Shale Gas ◽  
Global Economy ◽  
Large Scale ◽  
Oil And Gas ◽  
Small Scale ◽  
Tight Oil ◽  
Environmental Capacity ◽  
Unconventional Oil ◽  
Oil And Gas Resources ◽  
Unconventional Oil And Gas

Affected by the constant development of global economy and the imbalance in distribution of conventional oil and gas, oil and gas resources can no longer meet the demand in many countries. Development of unconventional oil and gas has begun to take shape. Shale gas and tight oil become the focus of global attention. Unconventional oil and gas resources are relatively abundant in China. Preliminary results have been achieved in the development of shale gas. Tight oil has been developed in small scale, and the main technologies are maturing gradually. Yet we face many challenges. Low in work degree, resources remain uncertain. Environmental capacity is limited, and large scale batch jobs will confront with difficulties.

scholarly journals The global economy affected by the COVID-19

2021 ◽  
Vol 129 ◽  
pp. 01030
Author(s):  
Ladislav Vagner
Keyword(s):  
Sensitivity Analysis ◽  
Earnings Management ◽  
Future Development ◽  
Global Economy ◽  
Value Added ◽  
Chinese City ◽  
Development Scenarios ◽  
Research Article ◽  
The World ◽  
Macroeconomic Indicators

Research background: The disease, which broke out in December 2019 in the Chinese city of Wuhan and caused a pandemic around the world, has a constant impact on the economies of the countries even after almost two years. The issue of the effect of COVID-19 on the global economy and overall earnings management persists. Due to the topicality of the problem, we focused on the impacts and measures affecting the company’s operation. Purpose of the article: The purpose of this research article is to summarize current information on coronavirus and its effects almost two years after the outbreak. Additionally, outline three different scenarios that could occur. We also took into consideration scientific sources that deal with the shock of COVID-19. In addition, we summarize the opinions of scientific authors. Methods: Within the methodology, we used mainly the analysis and obtaining an objective picture of the current situation in the world. Following the outbreak of the pandemic, there have been significant inconstancies in GDP. Subsequently, we focus on the development of individual selected macro indicators that best describe the global economy. Findings & Value added: Finally, we offer three scenarios that outline three different situations that may occur, which we worked on based on a scenario analysis based on a modification of the sensitivity analysis, to specify future development scenarios based on macroeconomic indicators.

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