Seismic responses in two kinds of reservoirs: Condensate gas and light oil

Oilfield X is lithologic reservoir composed of sandstones and mudstones. Due to the complicated seismic response mechanism, it is difficult to predict reservoir from seismic data in case of the following two types of reservoirs: condensate gas and light oil. From the new drilling well bs37, the two reservoirs are 80 meters apart vertically. They are both normal cycle and tested with oil and gas. However, there is a great difference between the seismic responses of the two sets: horizon ① is of strong reflection for most parts, but blank reflection for the reservoir; horizon ② is of strong reflection, and stronger reflection in the reservoir part. Why does a great difference exist between seismic responses of the two reservoirs under the same geological condition? In this study, petrophysical analysis, forward modeling, the effective reservoir thickness, P.V.T. (pressure/volume/temperature) test data results, gas-oil ratio and acoustic impedance intersections, and so on, are integrated to clarify the forming mechanism of the seismic response for the two sets of reservoirs. The combination of dynamic and static methods, for example the P.V.T. test results, the effective thickness and gas-oil ratio, are very key. Conclusion is that reservoir ① belongs to the normal cycle - weak reflection condensate gas reservoir and reservoir ② belongs to the normal cycle-strong reflection light oil reservoir. Presentation Date: Thursday, October 20, 2016 Start Time: 11:00:00 AM Location: 156 Presentation Type: ORAL