Modeling of dynamic fracture mechanism in rock masses  due to wave propagation

Finding a new oil well is a stimulating experience at all levels, however, it’s only an important milestone on the road towards exploiting oil and gas. When it comes to well drilling, the condition of the ground that surrounds the oil plays a major role. While there are many factors that dictate the success of exploring and drilling wells, porosity and permeability of the surrounding stone are some of the most important components.This paper focuses on the effective way to increase the porosity and the permeability of the rock using explosives without damaging the rock. In order to reach our aim, a numerical simulation was conducted. In fact, a 2D distinct element code was used, and 4 models were constructed; in each model the number of explosives increase while the blast load per explosive decreases.The dynamic stresses, and velocity vectors of the wave propagation were analyzed to evaluate the behavior of rock masses in each model. Moreover, a grid of history points was studied in order to compare the results and find the most suitable method to increase the crack propagation, therefore, the porosity and permeability along the rock masses, without damaging it.

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Buckling Failure Mechanism of a Rock Dam Foundation Fractured by Gentle Through-Going and Steep Structural Discontinuities

Sustainability ◽

10.3390/su12135426 ◽

2020 ◽

Vol 12 (13) ◽

pp. 5426

Author(s):

Donghui Chen ◽

Huie Chen ◽

Wen Zhang ◽

Chun Tan ◽

Zhifa Ma ◽

...

Keyword(s):

Numerical Method ◽

Failure Mechanism ◽

Shear Failure ◽

Distinct Element ◽

Mechanism Analysis ◽

Rock Masses ◽

Dam Foundation ◽

Deformation Features ◽

Universal Distinct Element Code ◽

Distinct Element Code

The failure mechanism analysis of dam foundations is key for designing hydropower stations. This study analyses the rock masses in a sluice section, which is an important part of the main dam of the Datengxia Hydropower Station currently built in China. The stability of the sluice rock masses is predominantly affected by gentle through-going soft interlayers and steep structural fractures. Its foundation failure mechanism is investigated by means of a numerical method, i.e., Universal Distinct Element Code (UDEC) and the geomechanical model method. The modeling principle and process, and results for the rock dam foundation are introduced and generated by using the abovementioned two methods. The results indicate that the failure mechanism of the foundation rock masses, as characterized by gentle through-going and steep structural discontinuities, is not a conventional type of shear failure mechanism but a buckling one. This type of failure mechanism is verified by analyzing the deformation features resulting from the overloading of both methods and strength reduction of the numerical method.

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Turkey

10.1093/wentk/9780199733057.001.0001 ◽

2012 ◽

Author(s):

Andrew Finkel

Keyword(s):

News Media ◽

Oil And Gas ◽

Historical Background ◽

The Road ◽

Eu Membership ◽

Western Democracy ◽

On The Road ◽

Kurdish Question ◽

The Military ◽

The Guardian

Turkey occupies a strategic position in today's world: culturally, historically, and geographically, it is the link between Islam and Western democracy, between Europe and the Middle East. The only predominantly Muslim nation to be a member of NATO and an ally of Israel, Turkey straddles both Europe and Asia. And it boasts an economy larger than any of the states that have joined the EU in recent years--Istanbul alone has a bigger economy than that of Hungary or the Czech Republic--with pipelines that carry much of the world's oil and gas. Andrew Finkel has spent twenty years in Turkey writing about the country for a number of leading news media such as The Economist and Time magazine. In this concise book, Finkel unravels Turkey's complexities, setting them against the historical background of the Ottoman Empire, the secular nationalist revolution led by Kemal Atatürk, and repeated political interventions by the military, which sees itself as the guardian of Atatürk's legacy. Finkel reveals a nation full of surprises. Turkey's labyrinthine politics often lead to such unexpected outcomes as leaders of the untra-nationalist party starting on the road to EU membership by voting to scrap the death penalty--which also meant giving a reprieve to the convicted leader of the Kurdish separatist movement. And where else but in Turkey, Finkel writes, would secularist liberals have supported a prime minister who was once jailed for promoting religious extremism? From the Kurdish question to economic policy, from Turkey's role in Iraq to its quest for EU membership, Finkel illuminates the past and present of this unique, and uniquely consequential, country.

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Simulation of Oil Well Drilling System Using Distributed–Lumped Modelling Technique

Modelling ◽

10.3390/modelling1020011 ◽

2020 ◽

Vol 1 (2) ◽

pp. 175-197

Author(s):

Panagiotis Athanasiou ◽

Yaser Hadi

Keyword(s):

Oil And Gas ◽

Long Strings ◽

Lumped Parameter Model ◽

Oil Well ◽

Drilling Depth ◽

Stick Slip ◽

Well Drilling ◽

Actual Measurement ◽

Breakdown Time ◽

Modelling Methodology

The strengths and torque of well-boiling hydrocarbons are of utmost significance. Boiling a well is one of the most critical steps in the discovery and production of oil and gas. The well’s boiling process is expensive because the drilling depth can be as much as 7000 meters. Any delay (breakdown time) in boiling costs a lot of money for hydrocarbon firms. Various boiler parameters are continuously tracked and regulated to avoid drilling delays. This paper focuses on the vibrations occurring at the bottom hole assembly (BHA) stick-slip. Two modelling methods, the lumped parameter model and the combination of the distributed–lumped (D–L) parameter model, were used and compared to the actual measurement performance. The D–L model was found to be more precise, particularly for long strings. Using the simulations, the most comprehensive modelling methodology is introduced.

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A brief analysis of behaviour possibility of a jointed rock mass near to longwall excavation face simulation using Distinct Elements Method (DEM) in the context of the Beam on Elastic Foundation (BEF) theory

E3S Web of Conferences ◽

10.1051/e3sconf/201910601015 ◽

2019 ◽

Vol 106 ◽

pp. 01015

Author(s):

Krzysztof Tomiczek

Keyword(s):

Rock Mass ◽

Elastic Foundation ◽

Distinct Element ◽

Beam Theory ◽

Wave Theory ◽

Jointed Rock ◽

Coal Bed ◽

Face Advance ◽

Rock Masses ◽

Distinct Element Code

Rock masses are discontinuous medium. Using the program based on the Distinct Element Method (DEM) UDEC (Universal Distinct Element Code) a 2D model of the rock mass near the longwall face was built. The UDEC code, due to its properties, is particularly suitable for modelling discontinuous and jointed rock masses. The coal bed lying at a depth of 700m had a thickness of 3m and was mined by longwall system with caving. The total face advance was 415m. The model had dimensions of 1500×500m (w×h). A vertical stress of σz=7.2MPa was applied to the upper edge of the model. The mechanized support protected the roof for a length of 4m at a distance of 2m from the face of the longwall. During simulation, among others, vertical displacements of roof and vertical stresses were closely examined. There were observed phenomena of bending, cracking, loosening and falling of roof blocks of rock. The results of numerical simulations were compared with the results of analytical solutions. The calculations were based on the solutions of the elastic foundation beam theory and the stress wave theory. Comparable shapes of arch pressure σzmax and the range of its impact were obtained.

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The formation of drilling equipment delivery scheme for oil and gas sector from China to Russia

Proceedings of Petersburg Transport University ◽

10.20295/1815-588x-2018-3-426-431 ◽

2018 ◽

pp. 426-431

Author(s):

Elena Matyushenko ◽

Yulia Kulakovanko ◽

Alexander Shepel

Keyword(s):

Oil And Gas ◽

Practical Importance ◽

Theoretical Concepts ◽

The Road ◽

Drilling Equipment ◽

Federal Districts ◽

On The Road ◽

Time Required ◽

The Cost ◽

Oil And Gas Sector

Objective: To study the practical aspects of the formation of the drilling equipment delivery scheme for the oil and gas sector from China to Russia. This is done in order to determine the possibility of optimizing routes and reducing the cost of transportation, taking into account the design features of the transported goods. Methods: The methods of systematization and generalization of theoretical concepts and statistical data were used. Results: The analysis of possible routes of international communication in the context of transportation of drilling equipment was carried out. The speciﬁcs of the main land routes of cargo transportation from China were determined. A formula for calculating the time required for transportation and handling of goods was introduced in order to compare the different routes and the delivery time. The calculation of time spent on the road during the transportation of drilling equipment along the route Beijing–Zabaikalsk–the Siberian and Ural Federal Districts was presented. The necessity to form an effective scheme for the delivery of oversized cargo for oil and gas sector based on the proposed algorithm was substantiated. Practical importance: The developed approach makes it possible to calculate the time spent on the way of various cargoes and apply the obtained results in the formation of an effective cargo delivery scheme. The recommendations presented in the article will help improve the quality of the logistics services provided, and increase the efﬁciency of the transportation process.

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Electrokinetics Application in Concrete and Well Construction

Volume 11: Petroleum Technology ◽

10.1115/omae2020-18275 ◽

2020 ◽

Author(s):

Narjes Jafariesfad ◽

Mette Rica Geiker ◽

Sigbjørn Sangesland ◽

Kamila Gawel ◽

Malin Torsæter

Keyword(s):

Oil And Gas ◽

Transport Processes ◽

Oil Well ◽

Coupled Transport ◽

Gas Wells ◽

Treatment Processes ◽

Oil And Gas Wells ◽

Porosity And Permeability ◽

Improved Performance ◽

Coupled Transport Processes

Abstract Electrically induced or coupled transport processes including electrophoresis, electroosmosis and electromigration in solutions and porous media under an external electric field have been extensively studied and employed in many disciplines. For protection and rehabilitation of concrete structures, cathodic protection, electrochemical realkalization, and chloride extraction are extensively used. Other electrokinetic techniques are developed for the concrete industry, but have not been widely used so far, including electrokinetic treatment processes, for corrosion mitigation, recovery from sulfate attack, crack healing, and porosity and permeability reduction. These processes can improve the microstructure of the cement-based systems resulting in an improved performance in long-term and can be applied to repair failed structures. Application of electrokinetic processes are rapidly extended in well construction due to the increased interest in techniques enabling manipulation of micro- and nanosized particles. The techniques could be beneficial in building a robust cement sheath in oil and gas wells. Additionally, electrokinetic remediation techniques can possibly be introduced for repairing damaged structures in oil and gas wells. This review provides an overview of electrokinetic-based techniques, which has been introduced to cement-based materials, mainly reinforced concrete. The potential application of these techniques in oil well construction is discussed.

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