Oil Pipe Research Articles

Heavy oil transportation through steam heating: An analytical and numerical approach

Amongst the innumerable challenges that permeate the production chain of heavy oils, the transportation stage deserves to be highlighted. Due to its high viscosity, heavy oils exhibit considerable flow resistance, requiring auxiliary mechanisms to enable its transportation via pipelines. This study analyzes a concentric pipeline configuration, in which steam flows through the inner pipe and oil flows through the annular space of the oil pipe. The main goal is to investigate the impacts of steam insertion, concentric coupling dimensions, thermal insulation, steam quality and system horizontal length on the main parameters of flow control: oil temperature and viscosity. As a secondary parameter, oil initial pressure required to ensure flow completion is also discussed. In this intent, a numerical approach is applied with software Ansys CFX in a tridimensional, steady state simulation. A second objective is to estimate the main parameters of interest by an analytical approach, using the thermal resistance model associated with the ε – NTU method. The goal is to determine if, given a similar coupling scenario and the absence of computational resources, oil temperature and viscosity can be estimated by direct calculations within an acceptable range of deviation from the numerical approach. Heat transfer rates are also estimated as secondary parameters. Numerical results for a 1-m length system reveal that steam insertion elevates the average oil temperature in 1.2%, reducing its average viscosity and initial flow pressure by 8.7% and 24.2%, respectively. From the previous scenario, a reduction of 24.6% in the oil pipe/steam pipe radius ratio results in an additional 1.2% temperature increase and 4.7% viscosity reduction. On the other hand, reducing steam quality in 30% implicates an average oil viscosity 2.4% higher. In a 4-m system, a convective cell pattern is observed, in which oil heating and viscosity reduction reaches its peak at the central upper region of the annular space, highlighting cooler and denser deposits in the lower section of the system and a nonlinear heating process. Maximum deviations between numerical and analytical approaches in oil temperature and viscosity estimates are 1.3% and 15.6%, respectively, which indicate the latter as a suitable calculation method for small systems in the absence of numerical resources. Deviations are mainly attributed to the neglect of natural convection, gravitational and steam turbulence effects, which contribute for a non-homogeneous heating of oil.

India's NRL secures environmental approval for $3 bn refinery expansion project

Amongst the innumerable challenges that permeate the production chain of heavy oils, the transportation stage deserves to be highlighted. Due to its high viscosity, heavy oils exhibit considerable flow resistance, requiring auxiliary mechanisms to enable its transportation via pipelines. This study analyzes a concentric pipeline configuration, in which steam flows through the inner pipe and oil flows through the annular space of the oil pipe. The main goal is to investigate the impacts of steam insertion, concentric coupling dimensions, thermal insulation, steam quality and system horizontal length on the main parameters of flow control: oil temperature and viscosity. As a secondary parameter, oil initial pressure required to ensure flow completion is also discussed. In this intent, a numerical approach is applied with software Ansys CFX in a tridimensional, steady state simulation. A second objective is to estimate the main parameters of interest by an analytical approach, using the thermal resistance model associated with the ε – NTU method. The goal is to determine if, given a similar coupling scenario and the absence of computational resources, oil temperature and viscosity can be estimated by direct calculations within an acceptable range of deviation from the numerical approach. Heat transfer rates are also estimated as secondary parameters. Numerical results for a 1-m length system reveal that steam insertion elevates the average oil temperature in 1.2%, reducing its average viscosity and initial flow pressure by 8.7% and 24.2%, respectively. From the previous scenario, a reduction of 24.6% in the oil pipe/steam pipe radius ratio results in an additional 1.2% temperature increase and 4.7% viscosity reduction. On the other hand, reducing steam quality in 30% implicates an average oil viscosity 2.4% higher. In a 4-m system, a convective cell pattern is observed, in which oil heating and viscosity reduction reaches its peak at the central upper region of the annular space, highlighting cooler and denser deposits in the lower section of the system and a nonlinear heating process. Maximum deviations between numerical and analytical approaches in oil temperature and viscosity estimates are 1.3% and 15.6%, respectively, which indicate the latter as a suitable calculation method for small systems in the absence of numerical resources. Deviations are mainly attributed to the neglect of natural convection, gravitational and steam turbulence effects, which contribute for a non-homogeneous heating of oil.

A Penalized Convolution Model for Oil Leakage Detection in Electrohydraulic Railway Point Systems

The railway point is one of the most critical systems in railway, which enables trains to be guided from one track to another. Failures of railway point systems often lead to service delays and hazardous situations. With the ever-increasing railway operation, the stable and safe operation of railway point systems becomes more and more important. The electrohydraulic railway point system is widely adopted due to its high efficiency and long service life. However, its operation highly relies on a sufficient volume of oil, which usually leaks gradually due to many practical issues, e.g., the wear of joint rings and the aging and corrosion of oil pipes. The gradual oil leakage often causes failures of electrohydraulic railway point systems, so it is important to develop the effective and reliable technologies for the early detection of slow oil leakage. To achieve this goal, the static oil level is used to construct the monitoring statistic since it is a direct indicator of the oil volume and more suitable for railway point systems than the hydraulic pressure due to the discrete demand for operations and the short duration of every operation. However, it is very challenging to utilize the oil level directly for oil leakage detection due to the large variability caused by the environmental temperature. Therefore, in this article, we propose a penalized convolution-based model to capture the relationship between the temperature and the oil level, whose parameters are estimated by using least squares with a smooth penalty. With the trained model, we obtain the residuals by removing the effect of temperature from the oil-level signal. Then, the CUSUM chart is employed to monitor the residual signal since it is sensitive to the small mean shift. Finally, the proposed method is evaluated through a case study by using in situ data collected from a real point system in Changsha Railway Station.

Enhancment of the corrosion resistance of copper metal by laser surface treatment

In this work, the copper metal was treated using Nd:YAG laser with energy 1Joul to enhance corrosion resistance and improve surface properties. The copper metal has many applications in industry as well as water, oil and gas pipes. The same conditions, (laser power density, scan speed, distance between paths, medium gas-air) were applied in the laser surface treatment, After laser treatment, the samples microstructures were investigated using optical microscope (OM) to examine micro structural changes due to laser irradiation. Specimen surfaces were investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), macro hardness, and corrosion test before and after laser treatment to examine the surface properties changes as a result of laser irradiation, and X-ray fluorescence (XRF). Results showed that laser irradiation enhances the corrosion resistance of the metal copper. Corrosion rates as low as 0.550 mpy for laser treated samples were obtained in comparison to 0.699 mpy obtained for the untreated samples. The corrosion protection afforded by laser treatment is attributed mainly to the grain refinement of the top surface layer. This layer is found to consist of nano-scale grains. Higher hardness and lower average roughness due to laser surface treatment.

Long fiber thermoplastic composite for offshore drilling application - Design and prototyping

Long fiber thermoplastic composite (LFT) has been mainly used in conventional applications such as automotive because of its low cost, great specific mechanical properties, excellent impact performance, excellent corrosion resistance and ease of processibility. All of these great properties enable it a potential material candidate in unconventional applications such as offshore gas and oil drilling. This work focuses on the design optimization, prototyping, and testing of a long glass fiber reinforced polyamide 66 (glass/PA66) stop collar for stabilizing buoyancy modules on a drill pipe for offshore gas and oil drilling application. Solid model is created using CREO and structural models are constructed using ANSYS Workbench with proper boundary and loading conditions. The material properties obtained from previous material studies are used for the modeling input and geometry design is optimized to achieve the required safety factor. The glass/PA66 stop collar is then prototyped using extrusion compression molding process. The performance of the LFT stop collars is finally validated with a slip testing and a successful practical run in a drilling operation.

Sediment detachment in piping‐prone soils: Cohesion sources and potential weakening mechanisms

AbstractSoil piping is a widespread land degradation process that may lead to gully formation. However, the processes involved in sediment detachment from soil pipe walls have not been well studied, although their recognition is a crucial step to protect soils from piping erosion. This study aims to recognize the factors affecting cohesion and to identify the mechanisms which are likely to be responsible for the disintegration of soil. The study has been conducted in mid‐altitude mountains under a temperate climate (the Bieszczady Mountains, the Carpathians, SE Poland). The research was based on the detailed field and laboratory analyses of morphology, and the physical and chemical properties of soil profiles with and without soil pipes. Moreover, experiments with flooding the undisturbed soil samples using different solutions (deionized water, ammonium oxalate, dithionate citrate, 35% hydrochloric acid and 30% hydrogen peroxide) were conducted in order to check the role of air slaking, the removal of soil organic carbon (SOC), and Fe and Al oxides on sediment detachment. The obtained results have confirmed that soil pipes develop in quite cohesive soils (silt loams), which allow the formation and maintenance of pipes with a diameter up to 30 cm. Soil cohesion, and thus susceptibility to piping, are impacted by the content of major oxides, soil particle size distribution, biological activity and porosity. The tested soils affected by piping erosion have a lower content of Al2O3 and Fe2O3, and free Fe (Fe(DCB)), lower clay content, higher biological activity (more roots and animal burrows), higher porosity, and more and larger pores than the profile without soil pipes. The experiments have indicated that especially SOC along with Fe and Al oxides are an important cohesion source in the study area. This suggests that the removal of SOC, and Fe and Al oxides may weaken and disintegrate aggregates in soil pipes. Further study of soil leaching and tensile strength will broaden understanding of which chemical processes control where pipes will develop in other cohesive piping‐prone soils. © 2020 John Wiley & Sons, Ltd.

Automation system for oil and gas service enterprises

The paper presents the results of the development of a single integrated solution for the automation of technological processes of service enterprises of the oil and gas sector, which allows to organize the work of production and management in a single information space. Algorithms have been developed to solve individual problems that are interconnected into certain algorithmic modules. The results of the integration analysis of modern automation systems of the ERP-class are presented, in particular, the level of adaptation to the stages of the product life cycle, compliance with standards and safety requirements, the complexity of the transition to the automation system. The results of the analysis of possible risks of the project during the implementation of this algorithm are presented. The practical significance of the development of a single production management algorithm is described. Finally, the treatise evaluates the main advantages and economic effect of the introduction of an automation system for an enterprise engaged in the production of oil and gas pipes at the process control level.

Electricity Transmission across South China Sea by Suspending Cables within Oil and Gas Pipes

Electricity Transmission across South China Sea by Suspending Cables within Oil and Gas Pipes

Role of bonding nature on the temperature dependent erosion behavior of solid materials: A detailed high temperature Raman spectroscopic analysis

Solid particle erosion is an unavoidable problem for gas turbine compressor blades, wind turbines, crude oil pipes, rovers in outer space, and other machine components operated in harsh conditions. Gas turbine components are usually operated in the temperature range of 100–1400 °C. However, the influence of temperature on the solid particle erosion mechanism has not been studied adequately. In this paper, the influence of temperature on the solid particle erosion properties of metals (Ti6Al4V, SS 304, Al-8011, and Ti/TiN multilayers) and non-metals (Al2O3, fused quartz, and Si) is studied. The erosion tests were conducted in the temperature range of 30–800 °C. The erosion rate of metallic and ionic solids (viz., Ti6Al4V, SS 304, Al-8011, Al2O3, and Ti/TiN multilayers with the thermal expansion coefficient α ≥ 8 μm/°C) initially decreased with increasing temperature and then increased at higher temperatures, whereas for covalently bonded materials such as fused quartz (α = 0.55 μm/°C) and Si (α = 2.6 μm/°C), the erosion rate increased with increasing temperature. As the temperature increases, it causes lattice vibrations and bond flexibility to increase the high thermal expansion coefficient materials due to their non-directional ionic or metallic bonds. It helps these materials to absorb the erodent energy without much damage, whereas the same does not happen in the case of low thermal expansion coefficient materials due to their strong directional covalent bonding. Temperature dependent Raman spectroscopic studies were carried out to understand the lattice vibrations and phase changes during heating.

Analysis of the Potential of Crust Formation and Corrosiveness in the Way Rilau PDAM Lampung Distribution Network Using the Langelier Saturation Index Method

Crust formation is a complex problem and always occurs in piping systems, both in oil piping systems, industry, and water distribution. When the crust is formed on the pipe, it will cause the pipe diameter to shrink and inhibit the flow of fluid in the pipe system. If the pipe has a problem, its temperature and pressure will be higher, increasing the possibility of the pipe to break and get damaged. This study aims to determine the formation of PDAM water pipe scale in Bandar Lampung with the Langelier Saturation Index Method. Based on the LSI calculation results, a value of -0.9 is obtained. This indicates that the corrosion rate is high, but there is no visible potential for scale formation. Formation of corrosion in the pipe can cause the pipe wall to thin out thereby increasing the potential for pipe leakage. Due to this, the checking of the pipes is necessary. Potential leakage of pipes will disrupt the distribution system and reduce service levels of PDAM Bandar Lampung City. Increasing the value of LSI in water can increase the pH of each water source. Increasing the pH will cause an increase in the value of LSI so that it is in neutral conditions and the level of corrosivity decreases. In addition, the flow velocity of water needs to be maintained with a minimum speed of 0.3 m/s to prevent the formation of scale on the pipes.

Pressure Control of High-Pressure Oil Pipe

In this paper, to realize the pressure stability control of high-pressure oil pipe, the dynamic differential equation of fuel oil inlet and outlet is established based on the theory of mass conservation. According to the change of the pressure in the high-pressure tubing, an optimization model is established to achieve precise control of the working time of each part of the high-pressure oil pipe.

A Review of Hydrate Formation in Oil and Gas Transition Pipes

This review provides a description of the various applications and issues of gas hydrate production in gas and oil pipelines, in general, gas hydrate is a clathrate of physical compounds, in which gas molecules are trapped in crystalline cells, formed by hydrogen bonds of water molecules. In the presence of water under various conditions, gas hydrates can be formed from all gases at high and lower pressures. The oil and gas industry have been taking stringent measures for many years to prevent the formation of hydrates which is plug pipelines by use. However, Natural gas hydrate is a non-conventional energy resource available to humans in colder regions, such as ice or sea bottoms. Other positive applications for natural hydrate include sequestration of carbon dioxide (CO2), storage, separation and transport of natural gas, the use of hydrate dissociation energy can be used in cooling and cool storage processes. The aims of this paper are to prevent gas hydrate’s formation that occur naturally in the oil natural gas transition pipelines, as well as the positive and negative that is remains from this natural phenomenon.

Study on the stability of tubing under pressure operation

The operation with pressure is to carry out the lifting and lowering of the tubing or oil rod without releasing the pressure. Compared with traditional downhole operation, the operation with pressure can ensure the upward and downward of the string without pressure relief. The effective plugging of the inside of the oil pipe and the annulus of the oil jacket is the main characteristic of the operation under pressure. When the tubing is lifted, the interior of the tubing is sealed and blocked due to the downhole pressure, it will generate upward force on the tubing, which will make it difficult to run the tubing. The project uses a down-pressure device to assist the down-flow of the tubing. If the down-pressure is too large, buckling instability occurs, which increases the construction difficulty for the down-run operation. Combining elasto-plastic mechanics buckling instability theory and finite element simulation method to study the compression stability of tubing under pressure. The variation law of critical buckling force of tubing diameter, length and wall thickness under pressure is analyzed by numerical model, which provides the basis for equipment design and process plan formulation.

Computational Fluid Dynamic Study on Oil-Water Two Phase Flow in A Vertical Pipe for Australian Crude Oil

A 3D steady state numerical model for the oil-water dispersed flow has been discovered to study the impacts of shear stress on the dispersed phase behaviour in a pipe with vertical situation. CFD tool by ANSYS software is used to investigate the wall shear stress and water droplet pressure. The flow range for the continuous process was explained through the resolution of the Navier-Stokes conservation equations with k–? turbulence model are summed in Reynolds. A recent experimental method analysis was simulated. The geometry is 3.2 m long and 38 mm in diameter tube. Oil droplet width has been presumed to be dependent on flow Reynolds number and it has demonstrated numerically for this case of study. When the mixture velocity Um of1.5 m/s, the droplet diameter Dd was found 4 mm. Shear stress was developed by current work for a different number of velocities (1.5,2,2.5 m/s) at oil fraction (cut off) is 0.2,the simulation results show that, the greatest shear stress value was at the uppermost point of pipe and it was 69 Pa.

Effect of Jet Impingement Velocity and Angle on CO2 Erosion-Corrosion with and without Sand for API 5L-X65 Carbon Steel.

Most oil and gas production wells have plenty of corrosive species present along with solid particles. In such production environments, CO2 gas can dissolve in free phase water and form carbonic acid (H2CO3). This carbonic acid, along with fluid flow and with/without solid particles (sand or other entrained particles), can result in unpredictable severe localized CO2 corrosion and/or erosion–corrosion (EC). So, in this work, the CO2 EC performance of API 5L X-65 carbon steel, a commonly used material in many oil and gas piping infrastructure, was investigated. A recirculating flow loop was used to perform these studies at three different CO2 concentrations (pH values of 4.5, 5.0, and 5.5), two impingement velocities (8 and 16 m/s), three impingement angles (15°, 45°, and 90°), and with/without 2000 ppm sand particles for a duration of 3 h in 0.2 M NaCl solution at room temperature. Corrosion products were characterized using FE-SEM, EDS, and XRD. The CO2 EC rates were found to decrease with an increase in the pH value due to the increased availability of H+ ions. The highest CO2 erosion–corrosion rates were observed at a 45° impingement angle in the presence of solid particles under all conditions. It was also observed that a change in pH value influenced the morphology and corrosion resistance of the corrosion scales.

Preparation and Application of Natural and Low Cost Palm Fibers as an Effective Drag Reducing Agent for Flow Improvement in Iraqi Crude Oil Pipelines

Flow of crude oil in pipelines suffers from a problem of fluid flow pressure drop and high energy consumption for fluid pumping. Flow can be enhanced using either viscosity reduction or drag reduction techniques. Drag reduction (DR) is considered as a most effective and most applicable method. The technique contributes in reducing the frictional energy losses during the flow by addition of little amounts from drag reducing agents. The present work focuses on preparation and application of a new natural and low cost material derived from palm fiber (PF) that has been tested as a drag reducing agent (DRA) for crude oil flow enhancement. This objective has been achieved through designing and constructing of an experimental rig consisting of: a crude oil pipe, oil pump, pressure sensors, solenoid valve and programmable logic control. The additive material (PF) is prepared with different diameters (75µm, 125µm, 140µm) and tested with different concentrations as: 100, 200, 300, 400, and 500 mg/L for reducing the drag inside the oil pipe. The experimental results showed that the fiber with 125µm diameter and 100ppm is the best where the percentage of drag reduction reached 43%. Furthermore, the results of this work proved that PF is an efficient and low cost DRA that can be applied successfully in crude oil pipelines as well as its contribution in the waste management.

Fuel system control design based on mass conservation

Fuel entering and ejecting high-pressure fuel pipe is the basis of fuel engine operation. The intermittent operation of high-pressure oil pump and injector will lead to the change of pressure in high-pressure oil pipe. This paper studies the influence of the opening and closing of one-way value and the speed of cam angle on the pressure in high-pressure oil pipe. Because the fuel flow is unstable in the high-pressure fuel pipe, it is necessary to determine the influence of pressure change on fuel density, and then calculate the mass of fuel supply and fuel injection in unit time. Considering the principle of mass conservation, the problem can be transformed into the length of single opening time of one-way valve when the mass of fuel entering and leaving the high-pressure oil pipe is equal in unit time interval. At the same time, by deducing the influence of the single opening time of the one-way value on the pressure in the high-pressure oil pipe, the single opening time of the one-way valve when the pressure of the high-pressure oil pipe reaches equilibrium after 2s, 5s and 10s is 0.610895ms, 0.425998ms and 0.373376ms respectively. Consider the working principle of the fuel system on the basis of the above considerations. Fit the function relationship between the needle lift and working time, deduce the change rule of flow volume of injector with time, and calculate the volume and mass of fuel injected by the injector in the working cycle. The results show that the high-pressure oil pump supplies oil 94 times in a working cycle of the injector, and the time required for the cam to rotate for one circle is 1.064ms, and the angular velocity of the cam is 5.906rad/ms. In this paper, based on the theory of unsteady liquid motion, mass conservation and energy conservation of fluid mechanics, many elements involved in the problem stem are analysed and related, and the control model of one-way valve switch and cam angular velocity is given.

COMPARATIVE RESISTANCE OF OIL INTERFIELD PIPELINE STEELS TO RILL CORROSION

Background The main cause of accidents at interfield oil pipelines, as experience in their operation shows, is the destruction due to corrosion. Aims and Objectives - to consider the main hypotheses on the breakage mechanism of interfield oil pipelines under the influence of rill corrosion; - to identify, on the basis of the published data and in-house experimental research, the main factors contributing to the initiation and behavior of rill corrosion; - to propose a methodology for testing pipeline steels for resistance to rill corrosion. Results It was concluded that the initiation of rill corrosion requires concurrent presence of such conditions as presence of solid abrasive particles in a water-oil emulsion, enrichment of the emulsion with oxygen, including its layers that are in direct contact with the bottom surface of the pipe, and the wall metal being under stress. Methodology is proposed to test pipeline steels for resistance to rill corrosion. Testing is proposed to be carried out on plates of 150 x 50 x 3 made from the rolled products of analyzed steels soaked in a 3 % aqueous NaCl solution with continuous aeration with air. The middle part of the plates is exposed to residual stresses close to the level of maximum equivalent stresses in the oil pipe wall, which is achieved by bending the plates in clamps until the required deflection arrow is reached, which is determined based on the value of the residual stresses and the type of tensile diagram of the analyzed steel. A notch is made in the middle part of the inner side of the plates, which serves as the initiator of additional mechanical stresses. After soaking the plates in a corrosive medium, the increase of the notch radius due to the walls corrosion initiated by the aggressive environment is analyzed for each of them; based on the analyzed value, with an account for the duration of the tests, the steel corrosion rate is calculated as per the mechanism of the grooving corrosion. Corrosion rates for four grades of pipeline steels (08kp, 17GS, 10G2FBYU, 10G2FBYU-U), determined during the steels testing according to the proposed method, are presented. Based on the comparison of the values obtained, it may be concluded that the steel 17 GS has a higher resistance to the rill corrosion, which complies with the published data on the breakage rates of interfield pipelines.

Simulation of the residual stress in a multi-pass oil and gas pipe weld joint

In this paper, a welding simulation procedure is developed using the FE software MSC Marc to predict the residual stresses.Numerical simulation was used to predict the thermal, mechanical and residual stresses behaviour in dissimilar material welded pipes which were found to be in good concurrence with experiments. Both two-dimensional FE model (2D) and three-dimensional FE model (3D) models are used to simulate the residual stressesin different directions in several regions of the weld zone under the same welding conditions. The 2D modelwas used toreduce the time and cost of numerical simulation.The aimof the present work is to understand the evolution of residual stresses (axial, radial and hoop stresses) in weldments. The results of thesimulationreveal that the hoop and the axial residual stresses around the weld region arenoticeablyvarying from those in the steady range.

Measurement of sound velocity in oil wells based on fast adaptive median filtering

Measurement of sound velocity in oil wells has long been a challenging industrial issue due to the difficulty in obtaining clear oil pipe coupling waves in strong noise. In this paper, a novel sound velocity measurement method is developed for the dynamic liquid level of oil wells based on fast adaptive median filtering. First, to solve the noise interference problem in the reflected oil pipe coupling wave, a fast adaptive median filtering algorithm is proposed to obtain an accurate oil pipe coupling wave. Then a curve fitting method based on range discrete coefficient is developed to estimate the sound velocity in the tubing-casing annular space of oil wells. The fitting sound velocity can reflect the propagation rule of the real sound velocity. In particular, the sound velocity at any position within the tubing-casing annular space can be accurately calculated by the fitting function. Finally, the proposed method is applied to the dynamic liquid level of an oil well. Experimental results show the effectiveness and favorable accuracy in estimating the sound velocity distribution.