Seismic Acquisition A 3D survey is designed based on: Land Operations Imaging Objectives: image area, target depth, dips, velocity, size/thickness of bodies to be imaged, etc. Survey Parameters: survey area, fold, offsets, sampling, shooting direction, etc. Balance between Data Quality & $$$$$ SLIDE 5 Today many of our seismic surveys (both land and marine) are to collect 3D seismic data However, there still are 2D surveys being collected We start by asking the ones familiar with the area about what they want to image E.g, an anticline at 9876 ft covering 10 sq miles and sands believed to be 150 feet thick This determines the survey parameters Survey area, the fold, shooting direction, etc. With seismic acquisition it is always a balance Good data quality is expensive What level of quality do you need to answer the business questions? The left picture is of a land seismic acquisition operation Four vibrator trucks work in tandem The right picture is of a marine seismic acquisition ship In the water you can see 2 airgun arrays You can also see 4 streamers (cables with hydrophones) Land Operations Vibrators Generate a Disturbance Geophones Detect Motion Marine Operations Air Guns Generate a Disturbance Hydrophones Detect Pressure Courtesy of ExxonMobil L 5 – Seismic Method