RCAAP Repository

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

The lack of pressure in the oil field makes the extraction of oil much more difficult. To solve this problem many techniques can be used. One of these is the electrical submersible pumps (ESPs) which are installed in the oil field. These pumps usually have many stages that are selected according to the height to be overcome. In some oil fields, sand production leads to an efficiency reduction and may even cause the destruction of the pump due to the erosion of its parts. In this case, the pump must be replaced resulting in great economic loss. In the present work an infrastructure was developed to simulate oil field conditions which include sand production, making it possible to study the wear mechanisms in this kind of application. The flow loop is constituted of a tank for water and oil or a mixture of both, an abrasive feeder, a hydrocyclone and a measuring system for torque, pressure, temperature and flow rate. The apparatus was successfully mounted and preliminary tests were carried out.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

The Friction Hydro Pillar Processing is friction welding process introduced in the early 90s. It is a solid-state welding process in which a hole is drilled and filled with a consumable rod of the same material. This method is capable of repairing long structure defects by a number of studs, welded sequentially along the defect, whereby a minimum in overlapping between two consecutive studs is assumed. This is a potential technique to repair steel structures in the offshore industry, since porosity and hydrogen embrittlementare strongly reduced in this process. In this work, the effects of the welded plate on the welding quality were studied. FHPP tests were carried out using steel plates of one, one and half and two inches. The axial stud load was 60 and 120 kN. The stud rotation was 1,400 and 1,700 rpm. Blocks studs and were machined out form ASTM A36 and AISI 1010 steels, respectively. The stud and base geometries were based on previous work conducted in the Laboratory for Friction and Wear Technology (LTAD). The block geometry was determined so that the block dimensions did not have any significant effect on the cooling rate. The welding tests were carried out using a welding system designed and built by LTAD. The unit consists of a hydraulic unit, a welding head and a control system. The unit is able to acquire and control the whole process according to the selected welding parameters. The main welding parameters are axial force, rotation, burn-off-length, forging force and duration. In order to evaluate the effects of the steel plate thickness on the cooling rate, thermocouples were welded close to the welding interface. The temperature as function of the time during the welding process for different plate thickness was acquired. The microstructure was characterized by using conventional metallographic techniques. The mechanical properties across the interface were evaluated by means hardness profiles. No welding defect was observed in metallographic sections for the selected welding parameters. Analysis of the effects of the welding plate thickness was complicated due to the fact that the selected welding plates showed chemical composition variations along their cross sections. Although, considering the equivalent carbon content it was possible to verify the effects of the plate thickness on the welding quality. It was observed that the higher the steel plate thickness the higher the cooling rate and the hardness.

Measurement Systems should be calibrated before use. Relevant legislation and technical standards in effect determine the calibration procedures and reference transducer that should be used to ensure traceability of calibrations and tests made with these systems. The importance of evaluation of uncertainty at all levels of the traceability chain is emphasized. In the development phase of a measurement system, its calibration has a unique importance because it allows the determination of the metrological parameters that characterizes it, as well as it´s capability. However, the market requires low cost, efficient, automated and versatile measurement systems. Therefore, this study developed a measurement system based on capacitive accelerometer ADXL321 of low cost for general aplications. Two types of direct calibration by comparison, one at 160 Hz and the other in frequency range 2 Hz to 20 kHz, were planned and ten experiments made. The data collected were analyzed and compared with those obtained with a standard measurement system. In following the uncertainty associated with all calibrations was evaluated, applying the methodology proposed in ISO/TAG 4/WG 3 (2008). Resulting in a measurement system of low cost with good accuracy, resolution 0.0006 V, dynamic range 19 dB, precision ± 0.0183 V, stable over time and expanded uncertainty of 4.58% for all calibrations.

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior