SEGJ Technical Conference

Simulation of time-lapse imaging for small oil/gas reservoirs at shallow and deep depths using a few ACROSS seismic sources and sparse receivers

Abstract Although demands of the time-lapse approach for the EOR are increased, the recent circumstance of oil price requires the reduction of geophysical exploration costs. The reduction of numbers of source and receives can contribute the costs in the time lapse, but it is necessary to keep good resolution. In this paper, we carried out two new simulations of reservoirs at 2 km and 200 m depths. In the 2 km depth model, we assumed only one ACROSS seismic source and a geophone array of 200 m spacing in 2D and 3D grids. The result of simulation gave a precise retrieval of the reservoir image. When we compare 5-m and 200-m geophone spacings in the imaging of 2D model, we could not recognize significant difference between two spacings. In the case of a very shallow heavy oil reservoir, a tiny target was well imaged. The receivers just above the target are more important for imaging. The real applications of our method to the oil fields might greatly contribute to reduce the installation and time-lapse monitoring costs.