Banca de QUALIFICAÇÃO: TATIANE DE GOIS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : TATIANE DE GOIS SANTOS
DATA : 07/03/2017
HORA: 08:00
LOCAL: Sala de reuniões do LEAP
TÍTULO:

STUDY, DEVELOPMENT AND APPLICATION OF MODELS FOR THE CALCULATION OF ANNULAR PRESSURE BUILDUP (APB) IN WELLS

PALAVRAS-CHAVES:

Rising in annular pressure, thermal expansion, confined fluids.

PÁGINAS: 105
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Civil
RESUMO:

The rising in annular pressure building (APB) is a thermal phenomenon that happens when oil wells suffer temperature variations through their lifespan, and is generally observed among the safety factors used for the well projects. Casing projects have to take into consideration high pressures, resulting from this effect to the annular, for raising the risk of increasing internal pressure or collapsing the casing in weak points, resulting in production loss or even, in the worst case, the well loss. Offshore wells are not equipped with the option of controlling their annular pressure, from distance, and deviating liquids relieved in a controlled volume. Unmanned platforms and wells in difficult locations face similar problems. Besides that, HPHT (high-pressure and high temperature) wells face high temperatures during long production times, which worsen the problem of pressure rising in annular, because the thermal expansion of liquids tend to increase the temperature even more. From this context, this thesis presents three models of pressure raising within the annular, to verify if a more simplified model can present an acceptable result. The first model, the simplest, considers that the thermal expansion of the fluid is governed by the ratio between the isobaric thermal expansion and the isothermal compressibility; the formation of balloon and reverse balloon, within the casing, by the variation of pressure and temperature, and the complete rigidity of the casing, in the part where it is cemented. The second model follows the same premises of the previous model; however, it also considers the deformation of the casing by the Poisson coefficient, as they are axially fixed columns. The last model considers a system of multiple sealed annular spaces as interactive systems, where those spaces influence each other, interdependently, and have a premise that the raising in the annular pressure, caused by the fluid heating, and the correspondent from the radial, tangential and axial tensions, acting to the pipeline, reach the balance through the well. For this last model, the casing is a thermoelastic compound, which deforms itself, even in contact with the cement, and the fluid is determined in terms of the variation of the fluid density as function of pressure and temperature, creating a non-linear system, to be solved by the Newton method. Results from the first models showed that they are overestimated, and more pronouncedly for the higher temperatures (and pressures) than for the lowest ones. On the other hand, the third model presented results with a good approach to the commercial program, used as reference, for any well configuration.

MEMBROS DA BANCA:
Presidente - 1149372 - TARCILIO VIANA DUTRA JUNIOR
Externo ao Programa - 1714865 - FLAVIO MEDEIROS JUNIOR
Externo ao Programa - 1754344 - MARCOS ALLYSON FELIPE RODRIGUES