The Study of High Energy Materials Used as in-Situ Heat Generation for Offshore Heavy Oil Thermal Recovery

Abstract

Abstract Thermal recovery technology is the development of the most effective way, including CSS, Flooding and SAGD, which can effectively solve the problem due to the high viscosity of heavy oil and poor mobility. However, it is difficult to recover heavy oil commercially and efficiently using conventional thermal recovery technology for offshore oilfields. That is because the limited platform area and sea water, which is commercial and easy for onshore fields. Downhole chemical thermal technology is widely used in heavy oil thermal recovery home and abroad. However, it is more used in plug removal, well bore hot washing and so on, because of its limited heat release. Due to its own advantages, high-energy material is suitable for application in heavy oil thermal recovery. Combined with the requirements of offshore oil field, high-energy material A is selected. Moreover, the heat released by the mixed reaction of agent A and agent B is used to heat the formation heavy oil, by the way of laboratory experiment and reservoir engineering calculation combined. N2 and CO2 are generated during the reaction, which reduces the viscosity of crude oil and replenish formation energy. The laboratory experiment results show that the high-efficiency chemical thermal reaction exotherm exceeds 1500 kJ/mol, which is three times that of the conventional chemical thermal reaction (300-400 kJ/mol), and no catalyst is needed. The method for controlling the rate of exothermic reaction was obtained by the research on influence factors such as salinity, solute concentration and pH. Reservoir engineering calculation results for 2 heat injection wells in a specific target block of Bohai Oilfield show that the cost can be reduced obviously. Meanwhile, agent A and agent B can be configured as an aqueous solution. The injection process is simple and the construction is convenient. This technology can be used in both huff and puff and flooding process as downhole thermal recovery. Moreover, it can be conducted in separate horizontal production wells as huff and puff, or it can be used in double horizontal well injection-production, five-spot pattern or other injection-production well pattern as WAG flooding. The injection process is simple and the construction is convenient. It is also suitable for processes such as wellbore cleaning, plug removal, thermal recovery auxiliary process and thermochemical stimulation in medium-deep heavy oil fields and offshore oil fields. It has a broad application prospect.