Asphaltenes: The Cholesterol of Petroleum

Abstract

ABSTRACT Asphaltene precipitation and deposition has been recognized to be a significant problem in oil production, transmission, and processing facilities. The precipitation of asphaltenes is caused by a number of factors including changes in pressure, temperature, chemical composition of the crude oil, mixing the oil with diluents or other oils, and during acid stimulation. The precipitated asphaltenes reduces the permeability of the reservoir near the well-bore region causing formation damage and can plug-up the well-bores and well tubings. Deposition of asphaltenic organic scales leads to operational problems, safety hazards and an overall decrease in production efficiency, thereby increasing the cost of oil production. This paper presents a review of the important factors which affect asphaltene precipitation in petroleum reservoirs and in processing facilities. The nature and characteristics of asphaltenes in the crude oil and their molecular and colloidal properties are discussed. A description of the asphaltene deposition problem manifestations in the reservoir, well bores and well tubings, processing and transportation equipment is presented. Current research work in this area is also discussed.