A seismic shift in exploration

VSFusion, a joint venture between Baker Hughes and CGGVeritas, uses seismic and wireline information to bring together time and depth, and geology and geophysics for a more dependable picture of the target. O&G spoke to VS Fusion’s Howard Simpson to find out more.

O&G. The digitization of oil fields around the world continues apace. What advantages does this bring to exploration and production teams?
HS. The move towards digital technology has allowed the development of multi-level downhole geophone arrays, which can be used either on industry-standard 7-conductor cables, or, in some cases, on single-conductor cables. This has yielded a new level of data volumes and data quality, allowing shorter survey times and higher resolution images of the sub-surface.

O&G. What role does VSFusion play in this industry development?
HS. The two co-venturers in VSFusion, Baker Hughes and CGGVeritas, have proven expertise in their respective fields, namely the wireline logging from Baker Atlas, and reservoir characterisation from CGGVeritas. The VSFusion joint venture has brought together these disciplines to create the largest group of experts dedicated to VSP processing, with a global footprint. The large datasets commonly being recorded (typically large 2D walkaway VSPs and 3DVSPs, are routinely processed by VSFusion to enable detailed analysis of the hydrocarbon reservoirs.

O&G. Vertical seismic profiling has been around for a number of years now. To what extent has the technology matured, and why is the time now right to expand its use?
HS. Zero-offset VSP geometries are very well understood, and modern software so powerful and flexible, that standard corridor stack processing is trivial. But since the advent of 3-component geophone recording 15 years ago, and multi-level arrays 10 years ago, a lot of additional information is there in the data that, even today, is largely disregarded. For example, even vertical VSP geometries can show a surprising amount of shearwave energy in the horizontal components, information that can be processed to yield higher depth resolution of the subsurface than by using P-wave energy alone. The large digital arrays in use now, allow the practical use of 3DVSPs as a drilling tool – the ability to produce 3D sub-surface imaging and velocity model update within a very short time after the completion of the data acquisition.

O&G. What applications are VSP technologies being used for in the oil and gas industry?
HS. The majority of VSP surveys are still being used to calibrate the surface seismic reflectivity, and provide an exact correlation between depth and two-way time, at least down to the TD of the well. But with each passing year, a higher proportion of more complex geometries are being recorded, to give additional structural information to the reservoir engineers. Offset geometries are being used to show faults, fractures and pinch-outs; walkaways are processed to solve for AVO calibration points, local and macro anisotropy studies as well as improved imaging; and 3DVSPs are giving high-resolution images or fracture studies.

O&G. What industry developments are you currently excited by? And are there any major challenges on the horizon?
HS. The advent of very large arrays – with the number of geophone levels going up to and beyond 100 – will allow huge quantities of walkaway and 3DVSP data to be recorded with just one pass of the seismic source. Recording many levels with one source output will mean reduced survey times, and a high degree of consistency at all depth levels, making the data processing easier. This, together with improved 3D visualisation, and integration of VSPs into surface seismic and other data types, makes it an exciting time to be in the business.

The main challenge comes in recruiting and training staff to meet the demands of the oil industry. The Big Crew Change, with the baby-boomers of the 1960s approaching retirement, means we have to work hard to find suitably qualified people just to replace those leaving the industry.

Howard Simpson graduated from the University of Bath, England, in 1984, with a BSc in Physics with Geophysics. In his early career, he worked on a surface seismic crew in Syria for GSI, and then in the Borehole Geophysics division of SSL in Keston, England. Through a series of acquisitions and mergers, the business became part of VSFusion, a joint venture between Baker Hughes and CGGVeritas.