Abstract A narrative on injection of CO2 for enhanced oil recovery considering the advantages of the integrally geared compressor over the single shaft compressor, and using the Siemens hermetically sealed canned motor-compressor in the process of separating export gas and CO2 for reinjection.
When injecting CO2 for EOR we have investigated the most important market requirements to identify the best solution from the existing portfolio of turbo machinery, when comparing a standard single shaft inline compressor to an integrally geared compressor, and have concluded, based on economics, efficiency, and power consumption, that integrally geared turbo compressors incorporate the optimum design concept for economic CO2 compression.
When re-injecting the produced gas after oil and gas separation there is a mix of saturated CO2 and hydrocarbons and other contaminants possibly containing hydrates, mercury and H2S. Gases and components which are preferably contained in the process equipment without possible leakages to the atmosphere due to seal leakages or malfunction of the compressor units dry gas seals. With the above in mind we developed a sealless (no dry gas seals) compressor which could add strategic benefits and eliminate the need for continuous flaring and venting of the seal gas and barrier gas to the atmosphere. And in conjunction with a fully categorized material selection provide the best solution with high availability and reliability.
Combined with the increased robustness of the overall system with less instrumentation and auxiliary systems and thus less spurious trips and downtime it is obvious that the integrally geared turbo compressor, STC-GV, in combination with the hermetically sealed compressor, STC-ECO, has the potential to considerably contribute to minimizing the environmental foot print, higher reliability and lower OPEX in the Oil & Gas operations especially in the process of mixed flow dirty gas separation found in the CO2 reinjection application.