Algorithm for Detecting Multiple Partial Blockages in Liquid Pipelines by Using Inverse Transient Analysis

SPE Journal ◽  
2021 ◽  
pp. 1-29
Author(s):  
C. Zhang ◽  
J. J. Zhang ◽  
C. B. Ma ◽  
G. E. Korobkov
Keyword(s):  
Inverse Problem ◽  
Crude Oil ◽  
Direct Problem ◽  
Pressure Response ◽  
Analytical Evaluation ◽  
Long Distance ◽  
Local Flow ◽  
Measuring Point ◽  
Detection Techniques ◽  
Oil Pipelines

Summary Partial blockages form on the inner wall of the crude-oil pipelines as a result of asphaltene precipitation, scale deposition, and so forth. If not controlled and rehabilitated periodically, these partial blockages can have a serious adverse effect on the efficiency, economy, and safety of the operation of the pipeline. Before each rehabilitation operation, the detection of the local flow-condition deterioration (change in diameter) is necessary for efficiency and economy considerations, especially for long-distance subsea crude-oil pipelines. Most conventional detection techniques require the installment of detecting devices along the pipeline. However, they are economically expensive and even technically impossible for pipelines in operation. The present work focuses on an economically efficient technique that can realize remote nonintrusive measurement (i.e., the pressure-wave technique). The purpose of our research is to develop a method for calibrating multiple irregular partial blockages inside the liquid pipe by using the pressure response in the time domain at certain measuring points along the pipe under the transient state. The method involves the direct problem and the inverse problem. The direct problem is the simulation of the transient flow in the liquid pipe with single or multiple partial blockages. A second-order direct problem solver is developed in the framework of the Godunov-typefinite-volume method (FVM). The inverse problem is to determine the partial-blockage distribution by using the pressure response at the measuring point under transient conditions. Our algorithm to solve the inverse problem comprises analytical evaluation and optimization. The analytical evaluation provides a reliable search space for the following optimization procedure, and thus effectively alleviates the local optimum problem. Numerical results demonstrate the efficiency and accuracy of proposed methods for solving the direct and inverse problems.

Investigation on Corrosion Base Characteristics and Deep Dehydration Technology of Micro-Droplets in Oil Pipelines

2019 ◽  
Author(s):  
Kai Guo ◽  
Yuling Lv ◽  
Limin He ◽  
Xiaoming Luo ◽  
Donghai Yang
Keyword(s):  
Particle Size ◽  
Electric Field ◽  
Crude Oil ◽  
Pitting Corrosion ◽  
Dispersed Phase ◽  
Water Droplets ◽  
Size Change ◽  
Long Distance ◽  
Oil Pipelines

Abstract Corrosion is an important cause of steel pipeline failure and oil leakage, especially local pitting corrosion in long distance crude oil pipelines. Deep dehydration is of great significance to pipeline anticorrosion, however, further experimental results show that it is very difficult to achieve deep dehydration by a single electric field. Recent studies have shown that the particle size change of dispersed phase for the emulsion with large droplets after electromagnetic synergistic treatment is more obvious than that of a single electric field. In this study, the effect of micro-droplets on corrosion of oil pipelines are revealed. The role of micro-droplets in the process of microbial corrosion and electrochemical corrosion in a strong or weak acid solution for oil pipelines was summarized. A structural model of on-line tubular electromagnetic synergistic intensification coalescing device was established. The size change of particle of the dispersed phase in emulsions was studied. Crude oil and water were used as experimental materials, and the particle size distribution of dispersed phase in emulsions was tested by the evaluation system. The results showed that mean radius, d10 and d50 of water droplets in emulsion treated by electromagnetic synergism are larger than those treated by a single electric field. Strengthening droplets coalescence by electromagnetic synergism is also effective on emulsions whose particle size of the dispersed phase is less than 100μm. The role of micro-droplets in pitting corrosion is summarized based on corrosion channels. In the process of microbial corrosion and electrochemical corrosion in strong or weak acid solution, the role of water is presented in two aspects like participating in the reaction and providing ion electron transmission media. Analogous to culture medium, micro water droplets can be called corrosion medium for pitting corrosion in long-distance crude oil pipelines. A structural model of on-line tubular electromagnetic synergistic intensification coalescing device was established, including an electric field generation device and a magnetic field excitation component with orthogonal distribution and synchronous synergy. And emulsions are treated by electric and magnetic fields while flowing through the medium channel. The particle size change of dispersed phase in emulsions with average particle size of dispersed phase less than 100μm was experimental studied. It is found that mean radius, d10 and d50 of water droplets in emulsion treated by electromagnetic synergism are larger than that by a single electric field. Therefore, electromagnetic synergism can further enhance the dehydration depth compared with a single electric field.

Thermal Characteristics Simulation of the Commissioning Process for New Buried Heated Oil Pipelines

2011 ◽  
Vol 301-303 ◽  
pp. 610-616 ◽  
Author(s):  
Guo Qun Chen ◽  
Ming Hua Zhao ◽  
Bo Xu
Keyword(s):  
Temperature Field ◽  
Crude Oil ◽  
Thermal Characteristics ◽  
Hot Water ◽  
Waxy Crude Oil ◽  
Long Distance ◽  
Warm Up ◽  
Oil Pipeline ◽  
Heated Oil ◽  
Oil Pipelines

For a new buried heated oil pipeline, the temperature field of the surrounded soil is natural. Therefore the temperature is usually low in this case. For the waxy crude oil whose pour point is higher than the ground temperature, if the new pipeline transports such oil directly after heating, crude oil may gel in pipeline because its temperature decrease dramatically due to heat exchange between the fluid and the surrounded soil. Hence, in practical situation hot water is often used to warm up the pipelines for most of the new long-distance buried pipelines. Crude oil transportation is determined after the soil temperature field around the pipeline is sufficiently high and the inlet water temperature meets the requirement.

scholarly journals The National Energy Board: Regulation of Access to Oil Pipelines

2016 ◽  
pp. 777
Author(s):  
Jennifer Hocking
Keyword(s):  
Economic Theory ◽  
Crude Oil ◽  
Competitive Markets ◽  
Long Distance ◽  
The Past ◽  
Economic Significance ◽  
Service Contracts ◽  
Oil Pipelines

In the past few years, a number of long-distance oil pipelines have been proposed in Canada — Northern Gateway, the Trans Mountain Expansion, Keystone, and the Energy East Project. This article describes the criteria used by the National Energy Board in approving the allocation of capacity in oil pipelines to firm service contracts while requiring that a reasonable percentage of capacity is allocated for uncommitted volumes (common carriage). It explains the economic theory related to regulation of access to major oil pipelines. It reviews and analyzes relevant NEB decisions, which show that the NEB supports well-functioning competitive markets, but will exercise its discretion to resolve complaints where markets are not functioning properly. The article also explains the economic significance of the proposed long-distance oil pipelines to Canada and Alberta despite the current low price of crude oil. The article concludes with recommendations for a written NEB policy regarding access to capacity in oil pipelines.

A refusal to grant access to a grid within the provision of crude oil transfer services as an example of a prohibited abuse of a dominant position in the EU and Polish competition law

2018 ◽  
Vol 5 (2) ◽  
pp. 199 ◽  
Author(s):  
Wojciech Paweł SZYDŁO
Keyword(s):  
Crude Oil ◽  
Competition Law ◽  
Eu Law ◽  
The European Union ◽  
Dominant Position ◽  
Oil Companies ◽  
Effective Competition ◽  
Oil Pipelines ◽  
Transfer Services ◽  
The Eu

Aim: The paper discusses cases in which a refusal by an energy enterprise to connect other enterprises to the network is treated as a prohibited abuse of the enterprise's dominant position and, equally, will represent behavior prohibited by art. 12 of the Treaty on the Functioning of the European Union and by art. 9 par. 2 item 2 of the Competition and Consumer Protection Law as well as legal consequences of such refusal. It is important to pinpoint such cases since the EU sectoral regulation does not provide for obligating any undertakings which manage and operate oil pipelines to enter into contracts with other undertakings such as contracts on connecting into their network or contracts on providing crude oil transfer services. Conditions for accessing oil pipelines and selling their transfer capacities are determined by the owners of the networks: private oil companies in the countries across which the pipelines are routed. These conditions are not governed by the EU law.  Furthermore, the very obligation of connecting other entities to own network by energy undertakings operating in the oil transfer sector in Poland will only arise from generally applicable provisions of the Polish competition law.  Design / Research methods: The purpose of the paper has been reached by conducting a doctrinal analysis of relevant provisions of Polish and EU law and an analysis of guidelines issued by the EU governing bodies. Furthermore, the research included the functional analysis method which analyses how law works in practice. Conclusions / findings: The deliberations show that a refusal to access the network will be a manifestation of a prohibited abuse of a dominant position and will be a prohibited action always when the dominant's action is harmful in terms of the allocation effectiveness. It will be particularly harmful when delivery of goods or services objectively required for effective competition on a lower level market, a discriminatory refusal which leads to elimination of an effective competition on the consequent market, a refusal leading to unfair treatment of consumers and an unjustified refusal. Originality / value of the article: The paper discusses the prerequisites which trigger the obligation to connect entities to own network by energy undertakings operating in the oil transfer sector. The obligation has a material impact on the operations of the oil transmitting undertakings, in particular on those who dominate the market. The regulatory bodies in the competition sector may classify a refusal of access to own network by other enterprises as a prohibited abuse of the dominant position, exposing such undertakings to financial consequences.Implications of the research: The research results presented in the paper may be used in decisions issued by the President of the OCCP and in judgement of Polish civil courts and EU courts. This may cause a significant change in the approach to classifying prohibited practices to prohibited behavior which represent abuse of the dominant position. The deliberations may also prompt the Polish and EU legislator to continue works on the legislation.

scholarly journals In-Line Analysis of Diffusion Processes in Micro Channels by Long Distance Raman Photometric Measurement Technology—A Proof of Concept Study

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 116
Author(s):  
Julian Deuerling ◽  
Shaun Keck ◽  
Inasya Moelyadi ◽  
Jens-Uwe Repke ◽  
Matthias Rädle
Keyword(s):  
Numerical Aperture ◽  
Spot Size ◽  
Measuring System ◽  
Optical Systems ◽  
Measurement Technology ◽  
Long Distance ◽  
Measuring Point ◽  
Acetone Concentration ◽  
Micro Channels ◽  
Set Up

This work presents a novel method for the non-invasive, in-line monitoring of mixing processes in microchannels using the Raman photometric technique. The measuring set-up distinguishes itself from other works in this field by utilizing recent state-of-the-art customized photon multiplier (CPM) detectors, bypassing the use of a spectrometer. This addresses the limiting factor of integration times by achieving measuring rates of 10 ms. The method was validated using the ternary system of toluene–water–acetone. The optical measuring system consists of two functional units: the coaxial Raman probe optimized for excitation at a laser wavelength of 532 nm and the photometric detector centered around the CPMs. The spot size of the focused laser is a defining factor of the spatial resolution of the set-up. The depth of focus is measured at approx. 85 µm with a spot size of approx. 45 µm, while still maintaining a relatively high numerical aperture of 0.42, the latter of which is also critical for coaxial detection of inelastically scattered photons. The working distance in this set-up is 20 mm. The microchannel is a T-junction mixer with a square cross section of 500 by 500 µm, a hydraulic diameter of 500 µm and 70 mm channel length. The extraction of acetone from toluene into water is tracked at an initial concentration of 25% as a function of flow rate and accordingly residence time. The investigated flow rates ranged from 0.1 mL/min to 0.006 mL/min. The residence times from the T-junction to the measuring point varies from 1.5 to 25 s. At 0.006 mL/min a constant acetone concentration of approx. 12.6% was measured, indicating that the mixing process reached the equilibrium of the system at approx. 12.5%. For prototype benchmarking, comparative measurements were carried out with a commercially available Raman spectrometer (RXN1, Kaiser Optical Systems, Ann Arbor, MI, USA). Count rates of the spectrophotometer surpassed those of the spectrometer by at least one order of magnitude at identical target concentrations and optical power output. The experimental data demonstrate the suitability and potential of the new measuring system to detect locally and time-resolved concentration profiles in moving fluids while avoiding external influence.

scholarly journals Role of Shearing Dispersion and Stripping in Wax Deposition in Crude Oil Pipelines

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4325
Author(s):  
Zhihua Wang ◽  
Yunfei Xu ◽  
Yi Zhao ◽  
Zhimin Li ◽  
Yang Liu ◽  
...  
Keyword(s):  
Crude Oil ◽  
Flow Rate ◽  
Critical Flow ◽  
Wax Deposition ◽  
Dominant Effect ◽  
Critical Flow Rate ◽  
Oil Pipelines ◽  
Oil Flow ◽  
Shearing Mechanism

Wax deposition during crude oil transmission can cause a series of negative effects and lead to problems associated with pipeline safety. A considerable number of previous works have investigated the wax deposition mechanism, inhibition technology, and remediation methods. However, studies on the shearing mechanism of wax deposition have focused largely on the characterization of this phenomena. The role of the shearing mechanism on wax deposition has not been completely clarified. This mechanism can be divided into the shearing dispersion effect caused by radial migration of wax particles and the shearing stripping effect caused by hydrodynamic scouring. From the perspective of energy analysis, a novel wax deposition model was proposed that considered the flow parameters of waxy crude oil in pipelines instead of its rheological parameters. Considering the two effects of shearing dispersion and shearing stripping coexist, with either one of them being the dominant mechanism, a shearing dispersion flux model and a shearing stripping model were established. Furthermore, a quantitative method to distinguish between the roles of shearing dispersion and shearing stripping in wax deposition was developed. The results indicated that the shearing mechanism can contribute an average of approximately 10% and a maximum of nearly 30% to the wax deposition process. With an increase in the oil flow rate, the effect of the shearing mechanism on wax deposition is enhanced, and its contribution was demonstrated to be negative; shear stripping was observed to be the dominant mechanism. A critical flow rate was observed when the dominant effect changes. When the oil flow rate is lower than the critical flow rate, the shearing dispersion effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. When the oil flow rate is higher than the critical flow rate, the shearing stripping effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. This understanding can be used to design operational parameters of the actual crude oil pipelines and address the potential flow assurance problems. The results of this study are of great significance for understanding the wax deposition theory of crude oil and accelerating the development of petroleum industry pipelines.

NUMERICAL SOLUTION OF THE INVERSE PROBLEM FOR A SYSTEM OF DIFFERENTIAL EQUATIONS

2020 ◽  
pp. 106-110
Author(s):  
S.E. Kasenov ◽  
◽  
G.E. Kasenova ◽  
A.A. Sultangazin ◽  
B.D. Bakytbekova ◽  
...  
Keyword(s):  
Inverse Problem ◽  
Differential Equations ◽  
Numerical Solution ◽  
Direct Problem ◽  
Nonlinear Differential Equations ◽  
Direct And Inverse Problems ◽  
Additional Information ◽  
Several Variables ◽  
Gradient Of The Functional ◽  
Objective Functional

The article considers direct and inverse problems of a system of nonlinear differential equations. Such problems are often found in various fields of science, especially in medicine, chemistry and economics. One of the main methods for solving nonlinear differential equations is the numerical method. The initial direct problem is solved by the Rune-Kutta method with second accuracy and graphs of the numerical solution are shown. The inverse problem of finding the coefficients of a system of nonlinear differential equations with additional information on solving the direct problem is posed. The numerical solution of this inverse problem is reduced to minimizing the objective functional. One of the methods that is applicable to nonsmooth and noisy functionals, unconditional optimization of the functional of several variables, which does not use the gradient of the functional, is the Nelder-Mead method. The article presents the NellerMead algorithm. And also a numerical solution of the inverse problem is shown.

scholarly journals Study on Optimizing Operation of Preheating Commissioning for Waxy Crude Oil Pipelines

2014 ◽  
Vol 6 ◽  
pp. 894256
Author(s):  
Jian Zhang ◽  
Yi Wang ◽  
Xinran Wang ◽  
Handu Dong ◽  
Jinping Huang ◽  
...  
Keyword(s):  
Crude Oil ◽  
Outlet Temperature ◽  
Fluid Temperature ◽  
Governing Equations ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Oil Pipeline ◽  
Single Station ◽  
Oil Pipelines ◽  
Volume Method

A mathematical model is established for the preheating commissioning process of waxy crude oil pipelines. The governing equations are solved by the finite volume method and the finite difference method. Accordingly, numerical computations are made for the Niger crude oil pipeline and the Daqing-Tieling 3rd pipeline. The computational results agree well with the field test data. On this basis, fluid temperature in the process of the preheating commissioning is studied for single station-to-station pipeline. By comparing different preheating modes, it is found that the effect of forward preheating is the best. Under different preheating commissioning conditions, the optimal combination of outlet temperature and flow rate is given.

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