High efficiency EOR and IOR technology on in-situ CO2 generation

Authors: A.Kh. Shakhverdiev (Institute of System Studies of the Oil-and-Gas Production Processes, RF, Moscow), G.M. Panahov, E.M. Abbasov (Institute of Mathematics and Mechanics of Azerbaijan National Academy of Science, Azerbaijan, Baku), R. Jiang (Beijing New Horizon Energy Technology Co., LTD, PRC, Beijing), S. Bakhtiyarov (New Mexico Institute of Minung and Technology (USA, Socorro)

Key words: carbon dioxide, porous medium, displacement, gas-generation, supercritical fluid, fringe.

Enhanced oil recovery by injecting carbon dioxide CO₂ as a tertiary hydrocarbon recovery mechanism under the water flooding is one of the ways to improve oil recovery, extend the oil field life and increase the efficiency of the oil field development in general. Despite the significant advantages of CO₂ injection the risks associated with capturing, transportation and storage of carbon dioxide significantly reduce the possibility of its application in EOR and IOR processes.

In this paper we present the results of longstanding experimental, theoretical and field research on the development and wide implementation of high-technology industrial method of in-situ generation of CO₂ gas-liquid slug has been shown. This process provides effectively regulation of the dynamic processes during oil displacement. Adjustability of gas generation dynamics of gas by controlling of carbon dioxide phase state, depending on the mineralization of water-based reactive agents under reservoir conditions. Laboratory tests demonstrate the technology efficiency in the processes of oil displacement on the core models. As a result of the widespread implementation of the technology on the oil fields of TNK, LUKOIL, SLAVNEFT (Russian Federation); SOCAR (Azerbaijan); Sinopec, CNOOC and PETROCHINA (China); GTT (United States, Oklahoma) significant results of additional oil recovery and increasing of oil recovery factor has been achieved.

First developed technology of residual oil recovery by the water flooding based on the in-situ formation of carbon dioxide under the process of sequential injection gas generating chemicals. Technology provides the implementation of gas generation process on the on-shore and off-shore development of oil fields. Efficiency and economic profitability of technology is determined by the special conditions of the gas-liquid creation slug no need to find industrial volumes of CO₂ sources and of pipeline infrastructure construction; making operations in remote areas, oil and gas regions with complicated climatic conditions; no need to build additional communications and power supply for CO₂ injection.