Sand Control Technology for Low pressure Lost-Circulation Wells and Application in South Sudan

A kind of plugging proppants was developed for solving the problem of ‘easy to lose sand’, resulting in difficult sand control in low pressure lost-circulation wells in South Sudan Oilfield. The proppants can cement together to form a consolidated body with certain strength (≥2 MPa) and permeability (≥1.3 μm2) in oil layers. The body can temporarily plug lost circulation channels. Meanwhile, a supporting sand-adding tool was developed to simplify the proppants squeezed process, and a sand-carrying fluid was optimized to improve sand suspension performance and protect pay zones in low pressure lost-circulation wells. These measures formed a sand control technology for low pressure lost-circulation wells. 12 wells have been successfully applied in South Sudan Oilfield and achieved good effect on increasing oil production by 15 t/d.

Assessment of Risky Cornering on a Horizontal Road Curve by Improving Vehicle Suspension Performance

Vehicle stability during cornering on horizontal road curves is a risky stage of travel because of additional factors acting. The main stability factor is centrifugal force, which depends on road curve sharpness and is very sensitive to driving speed usually controlled by the driver. However, the counterforce is produced at tire-road interaction, where different pavement types and states cause a wide variation of tire contact forces and vehicle stability. In the paper, the part of vehicle suspension performance while moving on a sharp horizontal road curve with different levels of pavement roughness was simulated by 14 degrees of freedom vehicle model. The model was built in MATLAB/Simulink software with available pavement roughness selection according to ISO 8608. The influence of variable suspension damping available in modern vehicles on risky cornering is analysed when a vehicle reaches the edge of the pavement with its specific roughness. Critical parameters of vehicle stability depending on road curvature, pavement roughness and driving speed are selected to assess the solutions for safe cornering.

Model predictive direct suspension force control of a bearingless induction motor based on sliding mode observer

PurposeThe purpose of the control method proposed in this paper is to address the problem of the poor anti-interference of the suspension winding current in the traditional bearingless induction motor (BL-IM) direct suspension force control process.Design/methodology/approachA model predictive direct suspension force control of a BL-IM based on sliding mode observer is proposed in this paper. The model predictive control (MPC) is introduced to the traditional direct suspension force control to improve the anti-interference of the suspension current. A sliding mode flux linkage observer is designed and applied to the MPC system, which reduces the error of the parameter observation and improves the robustness of the system. The strategy is designed and implemented in the MATLAB/Simulink and the two-level AC speed regulation platform.FindingsThe simulation and experimental results show that the performance of the BL-IM under the control method proposed in this paper is better than that under the traditional direct suspension force control, and the suspension performance of the motor and the anti-interference of the control system are improved.Originality/valueThis study helps to improve the suspension performance of the motor and the anti-interference of the control system.

Validation and Optimization of Suspension Design for Testing Platform Vehicle

With the application and popularization of the advanced driving assistance system (ADAS), the reliability and stability of ADAS have become its research focus. This article presents a car testing framework for ADAS reliability and stability. Its special suspension has been designed, verified, and optimized in real vehicles according to its working conditions. First, the structure and working principle of the testing platform vehicle are introduced. Then a simulation model is built in MATLAB/Simulink based on the dynamic equation to verify the working characteristics of the suspension. Experimental vehicle tests are conducted for simulation verification purposes. During the analysis, the root-mean-square (RMS) values of vehicle body displacement and dynamic tire deflection are considered evaluation indices. The nondominated sorting genetic algorithm (NSGA-II) is used to optimize the damping, stiffness, and installation position of the suspension system. The findings demonstrate that the specially designed suspension in this article can fulfill the test criteria. Compared with the optimized suspension performance, both the vehicle body displacement and dynamic tire deflection have decreased roughly by 17 and 40%, respectively, which significantly improves the suspension performance and provides a reference for the future designs of testing platform vehicles.

EVALUATION OF THE EFFECTIVENESS OF MAGNETIC SEPARATORS WITH FERROMAGNETIC BALL NOZZLE

Магнитные сепараторы с применением ферромагнитной насадки, имеющими высокие градиенты магнитного поля в рабочем пространстве, находят применение для очистки пылегазовых потоков и суспензий от магнитных примесей и являются достаточно экономичными в промышленных условиях. Исследованы полупромышленные сепараторы периодического и непрерывного действия с щаровой ферромагнитной насадкой для очистки антифрикционной присадки «Деста» от магнитных примесей. Для исключения потерь времени на промывку насадки, обеспечения постоянной производительности по суспензии и качества очистки суспензий авторами разработана конструкция и предложен метод расчета основных параметров сепаратора непрерывного действия. Проведены экспериментальные исследования работы сепараторов периодического и непрерывного действия одинаковых габаритов рабочего пространства и производительностей по очищаемой суспензии, которые показали неоспоримые преимущества сепаратора непрерывного действия. Magnetic separators with the use of a ferromagnetic nozzle, having high gradients of the magnetic field in the working space, are used for cleaning dust and gas flows and suspensions from magnetic impurities and are quite economical in industrial conditions. Semi-industrial separators of periodic and continuous action with ferromagnetic ball nozzle for cleaning the antifriction additive "Desta" from magnetic impurities are studied. To eliminate the loss of time for flushing the ferromagnetic ball nozzle, to ensure constant suspension performance and the quality of cleaning suspensions, the authors have developed a design and proposed a method for calculating the main parameters of a continuous separator. Experimental studies of the operation of separators of periodic and continuous action of the same dimensions of the working space and the performance of the cleaned suspension were carried out, which showed the undeniable advantages of a continuous separator.

Failure Analysis and Optimization of the Tie Rod Using FEA

A car’s steering wheel is used to connect the steering gear which is connect to the wheels via the tie rod ends. The main use of the tie rod end is to ensure the wheels are aligned. Hence the functioning of tie rod is crucial for steering as well as suspension performance of vehicle. Today’s world is competitive with respective to efficiency as well as economical in price, every organization striving for cost effective product at a lower price and within minimum period for ‘time to market. In this work, an attempt is made on optimization of the tier rod through changing materials and to reducing the weight. FEA analysis is performed on solid section and hollow sections with different thicknesses. The stress results at critical locations for different design iterations are discussed in this work. From the FEA results it is observed that the effected wright for hollow section is reduced by 18.15 % compare to solid section. Keywords: Tie rod, ANSYS, CATIA, Stress, optimization

Uncertainty Analysis of Quasi-Zero Stiffness Air Suspension based on Polynomial Chaos Method

In order to improve the vibration isolation performance of suspensions, various new structural forms of suspensions have been proposed. In this paper, a quasi-zero stiffness isolator is used in automotive suspensions to form a new suspension-quasi-zero stiffness air suspension(QZSAS).Due to the strong nonlinearity and structural complexity of quasi-zero stiffness suspensions, changes in structural parameters may cause dramatic changes in suspension performance, so it is of practical importance to study the effect of structural parameter uncertainty on the performance of such suspensions. In order to solve this problem, three suspension structural parameters d0,L0,Pc0 are selected as random variables in this paper, and the polynomial chaos expansion(PCE) theory is used to solve the suspension performance parameters such as body acceleration, suspension dynamic deflection, and wheel relative dynamic load response under different excitation. The sensitivity of the performance parameters to different structural parameters was discussed and analysed in the frequency domain. This paper verifies the feasibility of the PCE method for solving the uncertainty problem of complex nonlinear systems, and the research in this paper can provide a reference for the future structural design and optimization of such suspension systems.