AAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
New Generation Seismic (NGS) Acquisition with a Land Seismic Super Crew
(1) Exploration - XPO, Petroleum Development Oman L.L.C., Muscat, Oman.
In 2008, Petroleum Development Oman implemented New Generation Seismic to fulfil technical objectives while taking into account economical and efficiencies factors. The technical objectives are to obtain properly sampled and wide azimuth (WAZ) seismic for both shallow and deep objectives in support of current and future exploration and development projects. The sampling requirements to meet these objectives translate into receiver grids of 12.5 to 25m in-line by 200m maximum cross-line and full source VP grids no less than 400 VP/km2 (for example 50x50 m or 25x100 m). The WAZ requirement is to provide a minimum offset in all azimuths of at least the depth to deepest perceived target (typically 4km or greater). When combined, these sampling and width requirements result in New Generation Seismic with a fold exceeding 4000 in 25x25m bins suitable for full Common Offset Vector processing and full azimuth interpretation and quantification of azimuthally varying seismic attributes. Further, full top to bottom and high quality imaging is realized for both very shallow and very deep targets.
In order to efficiently acquire large areas, 10000+ km2, with over 400 VP/km2 two super crews were introduced. One super crew with a capacity of 25,000 channels (12 Geophone per station), and 16 vibrators, and the other with 16,500 channels (also 12 Geophones) and 16 vibrators. These super crews enable efficient operations with block widths in the range of 30+ km (a 30% efficiency improvement), and also fully productize dual methods of short sweep length simultaneous sourcing using both slip-sweep and distance separation (a 300% productivity improvement). In addition, the super crews now operate 24 hours per day (another 50% productivity improvement) and are equipped with the latest high channel count and high productivity SN428 recording system and VE464 vibrator electronics. While the throughput of these super-crews is approximately a factor 6 improved, the number of people needed in the field is a much more modest increase of approximately 50%.
As fully implemented in 2008, these super crews are consistently meeting PDO expectations and are setting world record productivity numbers. Daily average VP rates exceeding 13000 are common. Considering PDO’s minimum VP density of 400 VP/km2 these productivity numbers translate into an average production of 30+ km2 surface area per day per crew.