Simultaneous Multiwell VSP in the North Sea Using Distributed Acoustic Sensing

In a collaborative project between Silixa, Weatherford and Statoil, simulatneous multiwell VSP data were successfully acquired using intelligent Distributed Acoustic Sensing (iDAS). The iDAS enables the use of an optic fibre as a massive seismic sensor array. In this field trial the iDAS was retrofitted to existing fibres installed for other purposes. Simultaneous measurements were carried out using 4 iDAS units retrofitted to fibres in three different wells coming up to the same platform. Several seismic lines were shot, e.g. one above each of the well tracks, while listening in the well directly below the shots and also in neighbouring wells at an angle to the shot line. All three wells were producing during the trial and the downhole seismic data were acquired without disturbing the well operations. Consequently data hold information about the flow in the well in addition to the seismic information.