Study of gas pipelines cracks using transmission and Compton scattering

Marcela Ferreira Freitas; Cesar Marques Salgado

doi:10.15392/bjrs.v9i2A.432

Authors

Marcela Ferreira Freitas Instituto de Engenharia Nuclear
Cesar Marques Salgado Instituto de Engenharia Nuclear

DOI:

https://doi.org/10.15392/bjrs.v9i2A.432

Keywords:

gas pipelines, densitometry, gamma ray source, Compton scattering, cracks

Abstract

Most of the natural gas production is transported through pipelines that require periodic inspections to evaluate the structural integrity of the pipelines due to possible defects caused by degradation that can rupture causing leakage of the fluid causing major disasters. Based on this, the project presents a methodology for predicting cracks in pipe used in gas pipelines. The approximation is based on the principles of gamma densitometry to calculate the density of the pipe wall in order to investigate possible cracks. The natural gas fluid is found in such systems and interferes in the density calculations and therefore will be considered in the simulations. The detection system uses a narrow beam geometry appropriately, comprising gamma ray source (¹³⁷Cs) and NaI(Tl) 3"x3" detectors for calculating transmitted and scattered photons. Different positioning angles of the detector are investigated. In this study, the MCNP-X code is used to perform the simulations, in order to develop a counting geometry. Simulations of different thicknesses of the crack were also used to determine the minimum thickness detected by the two NaI(Tl) detectors. Having equipment that can estimate cracks present in pipes used in gas pipelines, in addition to predicting their location can reduce costs and make a major contribution to this sector.

Views: 110
PDF Downloads: 143

Downloads

Download data is not yet available.

Author Biographies

Marcela Ferreira Freitas, Instituto de Engenharia Nuclear

CENS

Cesar Marques Salgado, Instituto de Engenharia Nuclear

DIRA

References

ACHMAD B. E HUSSEIN E.M.A., An X-ray Compton scatter method for density measure-ment at a point within an object, Applied Radiation and Isotopes, 2004. p. 805-814.

ANJOS, M.J. LOPES, R.T. E BORGES, J.C., Compton scattering of gamma-rays as surface inspection technique. Nuclear Instruments and Methods in Physics Research Section, 1989. p. 535-538.

ARENDTSZ, N.V. E HUSSEIN, E.M.A., Energy-spectral Compton scatter imaging. I. Theory and mathematics. IEEE Transactions on Nuclear Science NS-42, 1995. p. 2155-2165.

BERMAN, A.I. E HARRIS, J.N., Precision Measurement of Uniformity of Materials by Gam-ma Ray Transmission, Review Scientific Instruments, 25, 1954. p. 21-29.

CARLOS H.F.O., CLAUDIO S.C. Instrumented PIG of PETROBRAS results and prospects, XXI National Congress of Non-Destructive Testing, 2002 p.9.

SALGADO C.M., BRANDÃO L.E.B., NASCIMENTO C.M.N.A., SCHIRRU R., RAMOS R. E SILVA A.X., Prediction of volume fractions in three-phase flows using nuclear technique and artificial neural network, Applied Radiation and Isotopes, 67, 2009. p. 1812-1818.

SHARAF, J.M., Practical aspects of Compton scatter densitometry. Applied Radiation and Iso-topes 54, 2001. p. 801-809.

SILVA M. A., The use of PIGs in the inspection and maintenance of pipelines. Technology & Information Magazine - ISSN 2318-9622, 2015. p.38-52.

TRANSETRO, Natural Gas. 2014. Available at: <http://www.transpetro.com.br/pt_br/areas-de-negocios/gas-natural.html>. Last accessed: 27 may. 2017.

TBG, Pipeline. 2015. Available at: <http://www.tbg.com.br/pt_br/o-gasoduto/tracado.htm> Last accessed: 27 may. 2017.