High-pressure Oil Research Articles

The Pressure Control Strategy Adjustment of High-Pressure Oil Pipe

This paper is based on the background of China Undergraduate Mathematical Contest in Modeling Competition A in 2019. Corresponding analysis based on the data given in this question, calculated changes in pressure in the high-pressure tubing according to the different operating conditions for fuel entry and spewing out, in order to determine some operating parameters of the fuel injection system, so as to improve engine efficiency and economic efficiency. The differential equation is constructed by the mass conservation formula under the corresponding conditions, and using MATLAB to implement Runge-Kutta methods to find the numerical solution of the corresponding differential equation.

Dynamic performance of key components for hydraulic power take‐off of the wave energy converter

Since the input power of the real waves varies continuously and periodically, how to stabilise the operation and generation during wave energy utilisation has become an inevitable and significant topic. This study focuses on the wave energy converter of a hydraulic power take-off (HPTO) connected to a pendulum and studies the influences of the key components, i.e. the high-pressure accumulator, oil tank and flow control valve, on the operational stability of HPTO by simulations and experiments. Parameters of the high-pressure accumulator are analysed and optimised. The dynamic performance of the HPTO with or without the oil tank is also investigated. Besides, the functions of the flow control valve in the cases of excessive input power and load shedding are given. Results show that the key components play very important roles in the operational stability of HPTO. Reasonable configurations of the high-pressure accumulator and oil tank are significant to improve the quality of output power and stability. Appropriate actions of the flow control valve are beneficial to protection and stability. Therefore, these key components should be considered preferentially during the design of HPTO.

Energy Recovery Simulation Research of Demolition Robot Rotation Hydraulic System

When the robot rotates to brake, the oil circuit of the system will produce greater pressure impact due to the large moment of inertia. High pressure oil overflows through the relief valve, then the overflow back pressure provides negative torque to brake the turntable. The rotational kinetic energy is finally dissipated in the form of heat energy, resulting in the waste of energy and the increase of oil temperature as well as the decline of system performance. Therefore, a scheme of recovery and utilization of rotary kinetic energy is proposed, that is, to recover the kinetic energy of the turntable during the rotary braking and to use the recovered energy as auxiliary energy during the rotary start-up. Virtual.Lab-Motion and AMESim are used to establish the joint simulation model of the electromechanical and hydraulic system of the demolition robot. The simulation results show that the energy recovery efficiency of the scheme can reach over 65%, and the comprehensive energy saving efficiency can reach about 10%.

High-Pressure Soybean Oil Biodiesel Density: Experimental Measurements, Correlation by Tait Equation, and Perturbed Chain SAFT (PC-SAFT) Modeling

Biodiesel can easily become the crucial solution for environmental problems. The high production rate of soybean oil has been the subject of several research works to transform it into biodiesel. K...

A non-destructive fault diagnosis method for a diaphragm compressor in the hydrogen refueling station

Costly and time-consuming maintenance of the hydrogen compressors due to their frequent breakdown severely hinders the deployment and promotion of hydrogen refueling station (HRS), and effective condition monitoring and fault diagnosis is the key to reduce the unscheduled downtime of the compressor. This paper proposes a non-destructive method for fault diagnosis of diaphragm compressors for HRSs based on the acoustic emission (AE) signal. The AE signals in the time domain are segmented into angle-domain signals correspond to a working cycle. The feature events of the moving components are determined through the measured AE signal in both angle-domain and angle-frequency domain based on short-term Fourier transform (STFT). Those feature events signals are innovatively applied to identify the typical abnormal conditions of excessively high oil pressure, slightly inadequate oil pressure and seriously inadequate oil pressure, replacing the traditional and destructive pressure measuring method. The results show that this method can be used to effectively diagnose abnormal working conditions and indicate that this method can be utilized as a powerful tool in the non-destructive condition monitoring and fault diagnosis of the diaphragm compressors.

Ionic liquid in stabilizing asphaltenes during miscible CO2 injection in high pressure oil reservoir

The potential of ionic liquids to prevent asphaltene precipitation during miscible Carbon dioxide (CO2) flooding was investigated. Asphaltene dispersion tests were performed to compare the effectiveness of commercial inhibitors and the ionic liquids at ambient conditions. Based on the results 1-Butyl-3-methyl-imidazolium bromide [BMIM][Br], Ionic Liquid was selected and asphaltene onset pressure (AOP) was determined at high-temperature high-pressure conditions through isothermal depressurization experiments in PVT cell. The effect of CO2, organic solvents and [BMIM][Br] on AOP were documented and correlated with nodal pressure analysis of the reservoir/wells.The results show a 21% decrease in AOP compared to the untreated oil and about 46% decrease when 35 mol% of CO2 is solubilized in oil. [BMIM][Br] is seen to have higher activity when injected in solution with isopropanol-n-heptane compared to direct addition. The application of [BMIM][Br]in miscible CO2 flooded reservoir is found to have good potential in inhibiting asphaltene deposition within the reservoir and near wellbore nodal conditions.

3D CFD Simulation of Water Hammer in High Pressure Common Rail System of Diesel Engine

The water hammer pressure triggered by injection in the high pressure common rail system play a major role in precise controlling of diesel injection. In order to obtain a deep insight into the existing transient three-dimensional effects, a three-dimensional computational fluid dynamics (3D CFD) simulation of water hammer was performed. An adequate mesh and suitable physical model was generated using a commercial code. The transition SST model was applied to simulate the three-dimensional hydrodynamic calculation of the oil supply lines of high-pressure common rail systems. The accuracy of simulation was verified by comparing the results with experimental data. The fluctuation characteristics of pressure and velocity in high pressure oil pipeline and the three-dimensional flow field effect of pipe radial direction were analyzed in the course of water hammer pressure fluctuation propagation in high pressure common rail system. 3D CFD simulation can show more details than traditional methods.

Investigation of rolling/sliding contact fatigue behaviors of induction remelted Ni-based coating

In the present work, Ni-based plasma sprayed coating was prepared on the surface of AISI 1045 steel and subsequently remelted by induction heating method. On base of this, the rolling/sliding contact fatigue behaviors of the two coatings under different contact stress were studied. The results indicated that, the induction remelting improved the microstructure and microhardness of the coating, and changed the bonding form between the coating and the substrate from mechanical bonding to metallurgical one. The rolling/sliding contact fatigue performance of the sprayed coating was very poor and interfacial delamination was the only failure mode. However, that of the remelted coating was remarkably superior to the sprayed coating. Moreover, with the increase of contact stress, the fatigue life of the remelted coating decreased, but its Weibull distribution of fatigue life became more concentrated. The main failure modes of the remelted coating under different contact stress were pitting and spalling. The failure mechanism of the sprayed coating was that the weak interface bonding and the combined action of residual stress and shear stress resulted in the interfacial delamination. For the remelted coating, pitting was attribute to the combined action of contact stress and high-pressure oil wave, while the spalling resulted from the synergistic action of the residual stress and shear stress.

A study of new low-cost anti-scaling compound salt high-density solid-free killing fluid

A new low-cost anti-scaling compound salt high-density solid-free killing fluid system is developed by adopting the high-efficiency scale inhibition technology, using a newly-developed weighting agent, and taking cheap inorganic salts as the base fluid, to solve the problems that the common killing fluids for high temperature and high pressure oil and gas reservoirs include bromine, zinc, heavy calcium, etc. are poorly compatible with the formation water, pollutional to soil and highly corrosive to human body, and that the formate high density killing fluid has a high cost. The system contains neither solid-phase components nor divalent ions that are prone to scaling, such as calcium and magnesium ions. The salts used are all monovalent salts with a density of up to 1.70 g/cm3. Compared to the same grade of formate system, the cost is reduced by more than 50% while all the advantages of the formate system are remained. In addition, it is also consistent with the future development trend and the requirements of the national new safety and environmental protection for the low damage, low cost, high density, solid-free and non-toxic environment-friendly killing fluid system.

Tribological properties of the plate valve and rotor material of hydraulic vane motor on different ambient temperature

Deck machinery that is driven by the hydraulic motor is a key part for ship exploration in the polar area. In this paper, the hydraulic vane motor in deck machinery was taken as the research object. The material of motor shields was QT350-22L, which was used as the plate valve, and the rotor material was LC2-1. The rotor slides relative to the plate valve under the pressure of the high-pressure oil, and the surfaces worn damage. Wear tests were performed using a pin-on-disk structure under six different temperatures (room temperature (25 °C), 0 °C, −10 °C, −20 °C, −30 °C and −40 °C), two kinds of hydraulic oil(15# and 10# aviation hydraulic oil) and the two normal loads(150 N and 300 N)respectively. In order to analyze the wear mechanism of the friction test specimen under different condition, the surface morphology of the friction test was carried out by scanning electron microscope(SEM) and laser interference profilometer. As the temperature decreased, the coefficient of friction did not change linearly. At the temperature of −20 °C, the coefficient of friction was the smallest, and when the temperature was lower, the coefficient of friction increased slowly and finally stable. Moreover, typical wear and tear modes were different at different test temperatures. The factors were the mechanical properties of the material and the lubrication medium changed in the low temperature. Changes in oil properties affected oil film thickness and distribution and abrasive grain removal ability between friction pairs. According to the experimental results, the paper summarizes the failure mechanism of the hydraulic motor, which can not only optimize the design of the hydraulic motor but also provide reference data for the establishment of online intelligent fault diagnosis system of the marine hydraulic system.

Noise control and experimental study of a highpressure oil pump enclosure

ABSTRACTThe present experimental study has been conducted to evaluate the impact of an acoustic enclosure of high-pressure oil pump, which is used to reduce the noise emission of an automobile engine. The enclosure is double-layered and made of nylon 66 (PA66) as an outer structure and polyurethane foam as the inner material. The sound signals of the engine were measured separately without an acoustic enclosure and covered by the enclosure. The signals were measured with 5 microphones around the engine under two electric loading conditions (0% and 100% load). The results revealed that the sound pressure level (SPL) of the engine increased significantly with the high-pressure oil pump installed, and the gap between SPL was larger for 100% load than 0% load. Furthermore, the enclosure of high-pressure oil pump was effective to attenuate the engine noise at almost the entire audio frequency range. The SPL reduced approximately 2 dB within nearly the entire test frequency range, supporting the remarkable noise reduction effect of the high-pressure oil pump enclosure.

Development of an Advanced Finite Element Model and Parametric Study to Evaluate Cement Sheath Barrier

Cement failure is known as one of the major causes for loss of well control events. Cement design is considered as one of the top technological knowledge gaps in high-pressure high-temperature oil and gas exploration. The primary objective of this paper is to perform a parametric analysis and identify critical parameters affecting the mechanical integrity of the set cement sheath. To achieve the objective, three-dimensional finite element models consisting of concentric casings and annular cement sheath were created. The finite element model was validated by analytical calculations. Performance of cement sheath was assessed by analyzing radial, hoop, and maximum shear stresses at different loading conditions. A parametric study was conducted by individually varying influencing factors such as cement material properties, sheath dimensions, and wellbore pressure loads. Values of all parameters were normalized and represented on the same plot against mechanical stresses. Such response curves can be used to estimate whether cement will structurally fail because of various operational loads or material aging. The plot can also be utilized to rank various factors in terms of influence on cement’s performance. Sensitivity response reveals that wellbore pressure, cement material properties, and annulus pressure are major parameters influencing mechanical stresses in neat class G cement. The order of importance depends on the type of stress. Results indicate interfacial bond failure and radial cracking to be the more likely modes of failure for class G cement. Cement response curves can help design engineers and regulators alike in quickly evaluating short-term or long-term fitness-for-service of cement sheath from the perspective of structural integrity. Industry standards and guidelines can be improved by adding performance curves for standard cement recipes.

Controls of paleo-overpressure, faults and sedimentary facies on the distribution of the high pressure and high production oil pools in the lower Triassic Baikouquan Formation of the Mahu Sag, Junggar Basin, China

Large quantities of high-pressure oil pools have been discovered in the glutenite reservoirs with low porosity and low permeability in the Lower Triassic Baikouquan Formation of Mahu sag, Junggar Basin. Overpressure has a close relationship with the generation of high-production oil pools in the Baikouquan Formation. In areas with abnormally high overpressure, the daily oil and gas production of single wells is high. Geological and geophysical analysis, and two-dimensional (2D) basin models have been used to explain the mechanisms of overpressure in the Baikouquan Formation and to establish a hydrocarbon accumulation model of high pressure and high production oil pools. Based on the hydrocarbon accumulation model, the main controlling factors of high pressure and high production oil pools generation have been summarized, and the favorable accumulation zones have been predicted. The results show that the chief reasons for overpressure are disequilibrium compaction and the pressure conducted through faults. In the hydrocarbon accumulation model of high pressure and high production oil pools, the overpressure compels faults that connect source rocks with reservoirs to open and become the valid conductive systems, and the oil-bearing overpressure fluid charges into the Baikouquan Formation along faults and forms high pressure oil pools in the frontier facies glutenite reservoirs near the faults. The main controlling factors of oil accumulation are the paleo-overpressure of Fengcheng Formation source rock during the main hydrocarbon migration stage (the Early Cretaceous, before 146 Ma), the faults on the ancient nose-like belts of structural uplifts and the fan-delta frontier facies glutenite reservoirs in the Baikouquan Formation. According to the accumulation model, the fan-delta frontier facies glutenite reservoirs of the Baikouquan Formation can be divided into three sections based on the favorability of oil accumulation I, II and III, from good to bad.

Experimental study of growth kinetics of CO2 hydrates and multiphase flow properties of slurries in high pressure flow systems.

The formation and accumulation of hydrates in high pressure oil and gas pipelines bring great risks to field development and deep-water transportation. In this paper, a high pressure flow loop equipped with visual window was used to study the growth process of hydrates in a pipe flow system and slurry flow characteristics. Deionized water, industrial white oil and CO2 were selected as the experiment medium. A series of experiments with different initial pressures (2.5–3 MPa), liquid loads (7–9 L), flow rates (25–35 kg min−1) and water cuts (60–100%) were designed and carried out. Specifically, hydrate formation and slurry flow characteristics in two different systems, pure water and oil–water emulsion system, were compared. Both of the systems experienced an induction stage, slurry flow stage and followed by a plugging stage. Although hydrate growth gradually ceased in the slurry flow stage, plugging still occurred due to the continuous agglomeration of hydrates. Visual observation showed that there were obvious stratification of the oil–water emulsion systems at the later time of slurry flow stage, which directly resulted in pipe blockage. The hydrate induction time of the flow systems gradually decreased with the increasing initial pressure, initial flow rate and water content. And the induction time tended to decrease first and then slowly increase with the increasing liquid loading. For emulsion systems, the apparent viscosity and friction coefficient of the hydrate slurry increased with the increasing water content, indicating that there were higher plugging risks compared to the pure water systems. Moreover, the results of sensitivity analysis showed that the water content was the main factor affecting the hydrate induction time, followed by the influence of liquid carrying capacity and flow rate, and the initial pressure had the least influence on the induction time. Conclusions obtained in this paper can provide some reference not only for the prevention and management of hydrates in pipelines, but also for the application of CO2 hydrate as a refrigerant.

基于供喷平衡的高压油管压力控制

基于供喷平衡的高压油管压力控制

Final Report on EUROMET Project 881 / EURAMET.M.P-K7: High pressure comparisons between seven European National Laboratories Range 50 MPa to 500 MPa

An inter-comparison in the high oil pressure range was arranged in 2005 - 2007. The participating laboratories were CMI/Czech Republic, Metas/Switzerland, MIKES/Finland, NMi-VSL/The Netherlands, PTB/Germany, SMD/Belgium and SP/Sweden. CMI, Metas, NMi-VSL and PTB are pressure laboratories of the primary level, and the three others are traceable to LNE/France.The transfer standard was a Desgranges & Huot piston-cylinder unit with a nominal effective area of 1,96 mm2, mounted in a D&H 5316 balance body. The participants determined the effective area at ten nominal pressures from 50 MPa to 500 MPa in steps of 50 MPa. All the results were in a good agreement with the reference values, calculated as weighted means of the results from the four primary level laboratories. The results fully support the uncertainties claimed in the CMC tables of the participants.As the pressure distortion is the dominating source of uncertainty in this range, the claimed uncertainties were highest at 500 MPa, ranging from 5,6 · 10-5 of PTB to 1,2 · 10-4 of MIKES (expanded relative uncertainties, k = 2). Except for PTB, there were no big differences in the claimed uncertainties between the primary and the secondary level laboratories.Some of the participants underestimated the uncertainties when giving their results in terms of the effective area at null pressure S0 and the pressure distortion coefficient, λ. The uncertainties given by some others were unnecessarily high.The transfer standard was not as stable as expected, and the uncertainties of the reference values were to some extent increased by the observed drift.The comparison, registered as EUROMET Project #881, was started as an informal one between MIKES, Metas, NMi-VSL and CMI, and in the beginning the rules for EUROMET comparisons were not strictly followed.No links to other comparisons were made as the latest EUROMET key comparisons in the high pressure range were carried out more than twelve years ago. Linking will be made as soon as results from newer comparisons are available.Edited in 2018:The link between this comparison (EUROMET 881 / EURAMET.M.P.K7) and the key comparison CCM.P.K13 was calculated, and the original EUROMET 881 report (MIKES Publication J4/2007) was updated accordingly in 2018.KEY WORDS FOR SEARCHcomparison, pressure, effective area, piston cylinder, pressure balanceMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Research on Response Characteristics and Energy Efficiency of Power Unit Used for Electric Driving Mobile Machine

Nowadays, the hydraulic pump driven by the diesel engine is widely used as the power unit for mobile machines, which consumes a large amount of fuel and cause high emissions. One solution is to use the electric driving mode. In this paper, the energy consumption characteristics of 4 electro-hydraulic power units, which are a fixed speed motor or a variable speed motor to drive a fixed displacement hydraulic pump or a variable displacement hydraulic pump, are compared and analyzed respectively. The results show that the power unit which a variable displacement hydraulic pump is driven by a variable speed asynchronous motor has the highest cost-performance ratio. However, due to the limitation of the battery peak current, the dynamic response of the power unit is slow. To solve this problem, a new power unit is proposed which add an accumulator to the hydraulic pump outlet to recover the power unit braking kinetic energy. The high-pressure oil stored in the accumulator can be absorbed into the hydraulic pump inlet to improve the power unit starting and braking performance and energy efficiency. The starting and braking characteristics of the power unit with and without the accumulator are compared experimentally. The results show that, if the power unit is driven by the motor alone, the power unit response is slow, and the load pressure has a significant influence on the response time. After adding the accumulator to the hydraulic pump, the power unit starting and braking time could be shortened significantly, and the starting power demand is also reduced. The proposed power unit is further used to drive a hydraulic excavator. Under the same working conditions and operating characteristics, energy consumption can be reduced by 28.5% compared with using the variable displacement hydraulic pump alone.

高压油管的压力控制问题研究

高压油管的压力控制问题研究

Research on Pressure Pulsation Characteristics of Gerotor Pump for Active Vibration Damping System

High response, stable operation, small volume active vibration damping system and other intelligent hydraulic equipment have become the inevitable trend of future development. A compact low-pulsation gerotor pump is designed to meet these requirements, the theoretical flow pulsation of 8/9 tooth gerotor pump is analysed, and its pressure pulsation characteristics are also studied in this paper. The combined pulsation buffer is placed at the bottom valve plate high-pressure port of pumps. High-pressure oil passes through the honeycomb damping hole and enters the diaphragm volume chamber of the accumulator to form a combined pulsation buffer. Considering the effect of the pulsation buffer structure to reduce flow pulsation at different speeds, a test bench for high-speed gerotor pump pulsation characteristics is built, and the pressure pulsation of the gerotor pump with and without pulsation buffer is analysed at different speeds. Results show that the pressure pulsation frequency increases with pump speed. When the speed reaches 5500 r/min, 8/9 tooth gerotor pump without pulsation buffer outlet pressure pulsation reached 13.797% and that with pulsation buffer outlet pressure pulsation decreased to 9.871%, showing a 28.46% decline rate. At pump rotation speeds are 1500 r/min and 2500 r/min, the pulsation reduction ratios are 37.78% and 35.36%. The pressure pulsation of the gerotor pump can be evidently reduced by designing a combined pulsation buffer in this paper. Therefore, this high-speed and low-pulsation gerotor pump is suitable for active vibration damping system and other intelligent hydraulic equipment.

Design and optimisation of advanced bearing system for ultra-precision plastic electronics production systems

PurposeThe paper aims to use aluminium alloy to substitute steel as the main material of ultra-precision hydro-static bearing system for an ultra-precision plastic electronics production system to lower the manufacturing cost. The total cost of diamond turning and nickel-based electroless coating of an aluminium alloy bearing is expected to be less than the cost of manufacturing a stainless steel bearing.Design/methodology/approachThe paper used a large amount of theoretical calculation to obtain optimal specifications of the bearing system. ANSYS modelling was selected to simulate the deflection of the bearing shaft under high oil pressure. Hundreds of measurements were conducted after the bearing had been manufactured.FindingsThe paper provides industrial application insights on using aluminium alloy with a high-quality nickle-based electroless coating as a successful substitution of stainless steel. This created a more economic hydro-static bearing system.Research limitations/implicationsBecause of the time limit, different rotational speed tests shall be conducted in the future.Practical implicationsThe paper provides implications for the application of nickel-based electroless coating to improve the surface property and bending strength of aluminium alloy, as well as classifying ultra-precision diamond turning as an economic finishing process.Originality/valueThis paper has identified the importance of aluminium alloy with a nickel-based electroless coating as the substitution of stainless steel in a precision hydro-static bearing system.