Recording subsea VSP from your home office: Ultra-long stepout acquisition using DAS

We report the successful acquisition and subsequent processing of a zero-offset VSP in an ultra long step-out context. We simulated a subsea well with 69km worth of tie-in to the wellhead and acquired a zero-offset VSP both on DAS and with a standard wireline toolstring for comparison. Our approach combines hardware and processing strategies to tackling the long step-out challenge. We demonstrate the ability to record seismic data even at very large step-out, a requirement for subsea well monitoring.