Publications

Iliran High, located in South Sumatera is a shallow undeveloped heavy oil of 18-22 API density in Indonesia with depth of the potential formation 10 – 500ft with range of viscosity 200 – 600cp at reservoir temperature of 90-94deg F. Reference is made to IPA Paper published in 2021 with number IPA21-E-35, series of conventional oil and gas method were assessed for developing Iliran High, such as steam injection, radial jetting, chemical injection and variety in borehole size but none give optimum production result. It was identified that due to its low reservoir pressure, none of the conventional methods would work. Therefore, the open pit oil mining method was selected. IPA21-E-35 also describes the laboratory procedures and result in testing the oil mining to Iliran High reservoir. Since the laboratory tests have promising results, the next step would be to test this method in a larger study scale and to include real excavation result and larger scale extraction. Preparation for this study will include preliminary studies (hydrogeology and geotechnical) with the objective to design the pit mining and ensure its safety by taking samples from limited corehole in the area objective; excavation study which was to retrieve ore from the producing formation; and extraction study, the final study to extract the excavated ore based on the extraction parameters from the laboratory scale study. The preliminary studies were able to determine the pit slope and design. The excavation study was conducted afterwards retrieving 20m3 of ore from the Telisa formation as the producing formation objective after removing top soil and overburden. The extraction of oil, which was conducted after the ore were transported to the extraction laboratorium, have undergone series of troubleshooting but managed to successfully extract oil from the Iliran High ore. The key lessons learned from the troubleshooting is, prior to conduct large scale extraction, always test and analyze small scale extraction and update on the extraction parameters. The overall results of this study has achieved its initial objective, which was to determine whether this oil mining method will give a profitable result. The studies shows that based on the extraction result, the recovery factor achieved is > 80% with total petroleum hydrocarbon (TPH) < 0.5%; comply to the minimum requirement of the environment regulation. Even though the result of this study is overall satisfactory, however, there are other aspects that needs to be considered if this method to be applied on a large scale: the scale of this study, even though larger than the laboratory scale study, is still very small compared to the full field scale. There are still a lot of aspects that have not been considered or elaborated during this study execution, such as: land acquisition strategy, heavy equipment fleet design for full scale operation, and currently there is no reference to plant extraction that performs extraction from ore rocks at a large continuous scale.