Publications

Low frequency seismic signal anomalies in data obtained from broad band sensors correlate to the presence of hydrocarbon reservoirs. Whether the observed signal originates as an emission from within the reservoir, or is a result of low frequency wavefield scattering effect of the acoustically anomalous hydrocarbon reservoir within an otherwise relatively homogenous subsurface, is the subject of testing and research. Previous available research has analyzed this low frequency data from passive seismic especially in exploration projects, but in this study we applied this research to field development. The passive seismic technique uses a seismometer to record low frequency signal at the surface typically applied above a known closure. The X-Field is a field development opportunity of an old oil field and the objective of this project is to assess if there is still hydrocarbons in the subsurface. This study undertook approximately 114 points of measurement in the area of interest. After field acquisition, the raw data were processed to allow maximum and minimum spectrum ratio (V/H) to be calculated. The hydrocarbon bearing reservoir are interpreted to show high V/H ratio (cut off : V/H > 1) in 1-6 Hz low frequencies. The relative strength of hydrocarbon-related signals are mapped over a survey area as vertical amplitude anomalies.. The result of the study shows there are oil indicators at the top of our predicted prospect as shown on the V/H map. These anomalies were used to propose well locations. With the data limitations from the existing well, the passive seismic data helps us to predict the presence of hydrocarbon. The research outlook for this technique is positive and we believe there is increasing potential for the usefulness and understanding of low frequency seismic applications for oil and gas exploration and development. Keywords : Passive Seismic, Amax (V/H ratio), Low Frequency Signal, Old Oil Field