NESTVOLD, E. O., Schlumberger: GECO-PRAKLA

ABSTRACT: Developments in 3-D Seismic Technology with Emphasis on Reduced Turnaround Time

Since the first three-dimensional (3-D) survey 18 yr ago, the power of 3-D seismic to produce high-resolution images of the subsurface has been thoroughly proven. In addition to its initial use for structural mapping, 3-D seismic is used increasingly to evaluate trends in reservoir quality.

These advances in 3-D seismic imaging, and the increasing speed with which such images will be available to the explorationist, can add to reserves by enabling oil and gas to be found in "fairway" locations that might have been missed, and by finding supplementary accumulations around and below producing fields.

When allied with reservoir modeling techniques, 3-D seismic imaging can contribute also to enhancing the recovery from oil and gas fields.

Drilling costs dominate both exploration and development expenditures. Wells are being saved with a better imaged subsurface and, consequently, downward movement of development costs in the near term is taking place. One can envisage extra oil reserves becoming economic as time progresses, simply because of reductions in development costs.

Most probably, 3-D will become an even more significant part of the total geophysical effort in the future, with surveys planned earlier in the exploration/appraisal/development cycle, and with each survey covering a larger area. Technical advances will continue to bring improvements in subsurface resolution. Improved quality control, coupled with ever more powerful computers, will bring about significant reduction in turnaround times.

Examples will demonstrate these technical advances and a strategy for reduction in turnaround times.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.