New heavy aggregate for offshore petroleum pipeline concrete coating Central West Sinai, Egypt

Abstract

In this paper the local materials used in concrete mix are studied in a manner that they can resist the aggressive marine environment and mechanical damage, which can occur at several stages during transportation, construction and installation of the pipelines. In earlier studies we succeeded in finding the Egyptian ilmenite ore adequate for concrete weight coating and already utilized for many pipeline projects in Egypt. According to the presence of about 30% titanium oxides in ilmenite composition which may be extracted to be used in others strategically fields, the object of this paper is to study and evaluate the mechanical, chemical and physical properties of another local hematite high density iron ore to be used in subsea concrete weight coating for offshore petroleum pipelines. The results indicate that the local material of Um Bogma hematite iron ore can substitute both imported iron ore and local ilmenite from Abu Ghalaga in this field to reduce the cost effective and increased economical value of local ores. Laboratory and field tests were conducted for the hematite ore forming a concrete mix, composed of hematite ore, cement and fresh water according to international concrete coating specification requirements, the ore produces a concrete mix with 190–195pcf minimum dry density and compressive strength, after 28days of hydration, varying from 40 to 45N/mm2 (400–450kg/cm2) which comply with the international standards and specifications of submarine petroleum pipeline coating. In addition, local hematite shows superior results than local ilmenite and achieves 190pcf instead of 180pcf in case of using ilmenite.