The increasing oil demand is encouraging exploration to reach into deeper oceans. The ocean ground temperature poses the risk of the crude oil cooling to a temperature that could cause flow blockage due to paraffin formation. Oil companies can send several millions to handle this challenge due to lost production time. To solve this problem suitable insulation is added to the pipe to keep the oil at its extraction temperature and hence reduce paraffin formation. This article determines how a coaxial pipe with a wire mesh can provide suitable insulation properties with simplified structure. With increase in thermal resistance of sub-sea pipe, the loss of thermal energy of oil to cold sub-sea is reduced.
Studies have been made to determine the heat transfer conductance coefficient for the pipe. Different interstitial materials are used for mesh with different mesh numbers. The materials used are stainless steel, Inconel, titanium and tungsten. In addition to varying the wire material, the mesh count varies, stating its effect on the overall thermal joint conductance. It was found that a five mesh stainless steel wire cloth provides the supreme insulation properties. It is found that interstitially insulated coaxial pipe can reduce paraffin accumulation in during under water. Additionally, the results seem to show superior insulation performance when compared to current technologies.
The world majorly relies on the internal combustion engine as its major transportation source, to meet the increasing demand for oil. The excessively high demand for crude oil has lead industry leaders to conduct deeper offshore exploration to find new oil reservoirs. Further the deeper oil mining needs more crucial technology to ensure reliable oil flow and equipment maintenance. The components used to transport the oil serve at ocean floor temperatures that range from 0oC to 2oC.
Crude oil usually comprises wax that contains paraffin chains which remains dissolved when retained at production temperature. But the crude oil experiences temperatures below the 68oC, the wax crystallizes into solid particles causing accumulated on the internal surface of the pipe.
The average ocean ground temperature is 0 to 2oC which is almost a freezing point. The oil production temperatures are over 70oC and this temperature difference cannot be easily handled. So, it is crucial that alternative insulation methods are discovered to improve the thermal performance of deepwater pipelines.
Present methods for reducing the paraffin deposit on the interior wall include heat exchanger concepts, exterior wall insulation and external heating. Pipe-pipe heat exchangers work on thermal resistance network of convection and conduction to prevent heat flow from the oil. Thermal insulation and external heating sources help to retain high product temperatures whilst chemical additives strive to reduce the cloud temperature of the paraffin in oil. It is found that thermal insulation of oil exploration pipes by Inconel mesh and stainless steel mesh is high satisfactory. Hence, it becomes possible for oil engineers to dig deeper into the oceans to fine oil reservoirs easily.