STUDI SIMULASI INJEKSI TAK BERCAMPUR GAS CO2 HUFF AND PUFF UNTUK MENINGKATKAN PEROLEHAN MINYAK RINGAN PADA LAPANGAN “T”

• Main Author: Friska Y Tampubolon, Haryeni
• Format: Final Project
• Language: Indonesia
• Subjects: Pertambangan dan operasi berkaitan
• Online Access: https://digilib.itb.ac.id/gdl/view/54593
• Institution: Institut Teknologi Bandung

This paper presents the result of feasibility study aimed at extending the production life of an oil field in Indonesia through EOR (Enhanced Oil Recovery) employing the huff and puff CO2 injection technique. A black oil simulation model using detailed geologic characterization was built to optimize immiscible CO2 injection design. The model is a radial model with production and injection well are on the center of the model of reservoir. Several sensitivity runs were made to improve the CO2 solubility in oil and maximize the oil recovery. Immiscible CO2 injection mechanism that have been analyzed from this simulation are; viscosity reduction, oil swells, and increment of oil saturation. This study found that CO2 injection is influenced by pressure of injection, volume of CO2 injected, bottom hole pressure (BHP) and soaking time. The results are analyzed based on CO2 solubility in oil in varied conditions.The study results show that increment of injection pressure up to bubble point pressure increases oil recovery factor. Above the bubble point pressure, increasing injection pressure will not lead to improvement of CO2 solubility in oil for oil has been fully saturated by gas. Greater volume of injected CO2, longer soaking time and lower BHP will lead to more increment of reservoir pressure. Longer soaking time yields greater reservoir pressure which is built up and improvement of CO2 solubility in oil. It is also noticed that longer soaking time also gives longer non producing time for well which can result to reduction of oil recovery. The greater volume of CO2 injected, the more CO2 is soluble in oil. Thus, the more CO2 is produced during the production time. Lowering BHP increases pressure drawdown of well but also leads to releasing more CO2 from oil. This results in greater gas production rate and lower oil production rate. Based on the simulation study, the optimum desain for CO2 immiscible injection huff and puff is obtained with the conditions : 1000 psia of injection pressure, 0.5 PV injected, 30 days soaking time and 100 psia BHP.