Synthesis of a tough montmorillonite/hydrogel composites for hot work of long-distance oil pipelines

Author(s):  
Tao Fan ◽  
Zhenyi Liu ◽  
Yao Zhao ◽  
Mingzhi Li ◽  
Xuan Li
Author(s):  
Huijuan Wu ◽  
Ya Qian ◽  
Hanyu Li ◽  
Shunkun Xiao ◽  
Zhizhong Fu ◽  
...  

SPE Journal ◽  
2021 ◽  
pp. 1-29
Author(s):  
C. Zhang ◽  
J. J. Zhang ◽  
C. B. Ma ◽  
G. E. Korobkov

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.


Author(s):  
Kai Guo ◽  
Yuling Lv ◽  
Limin He ◽  
Xiaoming Luo ◽  
Donghai Yang

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.


2014 ◽  
Vol 638-640 ◽  
pp. 51-57 ◽  
Author(s):  
Zhi Ping Ren ◽  
Chang Hua Liu ◽  
Feng Feng Bie

When the long-distance oil pipeline under rivers (referred to as river-crossing pipelines) are damaged by the third-party, they are prone to nudity or left vacant, and the oil pipelines under the action of water flow will cause pipeline failure; and the distance of suspended pipeline is longer than the allowed length will cause the pipeline resonance. In order to avoid pipelines fatigue or broken, suspended pipelines are considered as part of the arc shape, and non-suspended pipelines are considered as the linear shape of the mechanical model with the two ends of the fixed pier synchronous. The study will consider the impact of water flow, buoyancy, the gravity of pipelines and its annexes, bending deformation and bending moment, do the tense calculation for suspended pipelines with external load and the vibration analysis for suspended pipelines under different water flow speeds. The results showed that: the design of river-crossing suspended pipelines not only needs to consider the impact of water flow, buoyancy, the gravity of pipelines and its annexes, bending deformation and bending moment, but also to consider the floating vortex-induced vibration of the suspended pipeline, which should cause pipeline designers, constructors and maintainers’ attention.


2011 ◽  
Vol 301-303 ◽  
pp. 610-616 ◽  
Author(s):  
Guo Qun Chen ◽  
Ming Hua Zhao ◽  
Bo Xu

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.


2016 ◽  
pp. 777
Author(s):  
Jennifer Hocking

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.


2015 ◽  
Vol 38 (2) ◽  
pp. 95-104
Author(s):  
Riesto Mundi Karono

The existence of gas hydrates is well known in the oil and gas production industry. The components are dominated by methane and naturally occur in deep marine sediment along continental margins. Although hydrates may be of potential benefi t both as a hydrocarbon resource and as a mean of storing and transmitting natural gas, traditionally their presence is considered to be an operational and a safety problem. They can form at the pressures and temperatures found in natural gas and oil pipelines causing blockages, especially when temperature falls signifi cantly, such as when closing in a well or fl owing gas through a choke. This could deliver a serious potential problem for oil and gas offshore production either for its equipment or personnel. Besides the variation of gas rate to avoid hydrates forming, currently there are two methods that have been used widely to prevent hydrates formation in production pipelines - thermal insulation and chemical inhibitor. Each method has its own benefits. PIPESIM software application can be used to evaluate both mitigation methods and to then fi nd which is the best scenario based on lowest cost, shortest period of application and less adversity.


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