Advanced Asphaltene and Paraffin Control Technology

Abstract

Abstract Asphaltenes and paraffins deposit in the wellbore zone, tubing, downhole pumping equipment, pipelines, and in surface equipment and, also, cause a high viscous stable water-in-oil emulsion inside the tubing and surface equipment, dramatically decreasing well productivity. Modern asphaltene and paraffin control technologies and demulsification methods usually do not correspond and even may contradict each other, resulting a high cost and ineffectiveness of oil production. The advanced way to utilize the technological methods in the most efficient manner is creating a common technology to put on line several asphaltene and paraffin problems. The current paper discusses an optimal stimulation method recovering the mentioned above problems by using just one treatment. The method consists of a periodical application of detergent designed to remove the deposit and simultaneously to destroy the water-in-oil emulsion. In addition, the detergent adsorbing on the equipment surface prevents further asphaltene and paraffin deposition. Introduction Asphaltenes and paraffins are constituents of many crude oils. Paraffins and asphaltenes remain oil components in the most oilfields in Russia (Siberia, the Tatar Autonomous Republic, the Bashkir Autonomous Republic, and other regions) and in Kasakhstan. Low API gravity oils in California, Venezuela, West Texas, Middle East, and Trinidad also have primarily asphaltenes as their constituent. Paraffin and asphaltene deposition in subsurface and surface equipments and wellbore is one of the major problems in production operations. Change of the physicochemical equilibrium conditions mainly due to temperature decrease bellow the melting point causes a loss of the paraffin and asphaltene solubility in crude and the heavy oil components may start to accumulate on the production equipment and in the wellbore. The deposit built up in the tubing may overload the rod-pump and cause rod breaks, as well as the deposit may decrease the cross section area of the rod-pump channels and valves, tubing, and pipeline. The deposition in the wellbore reduces the wellbore permeability. Usually oil production with paraffins and asphaltenes is followed by a fast water invasion into the reservoir and water breakthrough causing the high water cutting of the pumping well production and the high viscous stable water-in-oil emulsion. In summary, crude oil production containing asphaltenes and paraffins faces with several problems on the entire way of the oil movement from the wellbore to the surface demulsification equipment. All of these problems result a significant decrease of the oil well productivity. p.421