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Technology Information Session	1997 07 15 A New, High Resolution Integral Transform for Multiple Filtering INVITATION Dr. George Adler, President of Adler Mathematical Ltd., and Husky Oil invite you to attend an information session on "A New High Resolution Integral Transform for Multiple Filtering." Date: Tuesday, July 15, 1997 Time: 11:30 - 1:30 p.m. Location: Plus 30 Conference Centre Conference Room ‘C' Western Canada Place 707 - 8th Ave. S.W. Calgary Background Reflection seismology, as used in petroleum exploration geophysics, uses sound energy, reflected from the boundaries of the geological layers or other discontinuities, to create an image of the cross section of the earth. Very often a large portion of the sound energy reverberates between the layers before reaching the recording instruments. These delayed reflections, shortly called multiples, create multiple images of the same layer, and usually obscure other important features by overlapping them. 2. The "state of the art" Because of the importance of eliminating these multiples during the seismic processing, much effort has been concentrated on filtering them from the data. In a publication describing his method, Dan Hampson, the author of the most commonly used multiple filtering package (see JCSEG, 1986, 22, p44-55.), describes a reasonably formulated solution of the problem (suggested by previous researchers) as "prohibitively time-consuming." This is true because the method requires the solution of a large linear system of equations. For the originally formulated mathematical problem this assertion seems to be still valid. As a result, the methods used for multiple elimination are very simplified and suffer from the following shortcomings: they require the assumption of "hyperbolicity" of the events they approximate the difference between two hyperbolae by a parabola their resolution is low they smear out the filtered data, i.e., the amplitude versus offset (AVO) effects are altered the computation times are long The new integral transform We developed a new integral transform method that manipulates data in the original offset-time state, without Normal Move Out (NMO). By defining the curvilinear integral appropriately and by developing unexpected, important "short cuts" in the construction of the linear system of equations, we were able to reduce the computation time, for the practically error free solution, below the time requirements of the presently used very approximative methods. The method also checks the "tentative" solution against the original input and corrects itself to remove any residual error. The new method has the following advantages: extremely high resolution no noticeable smearing of the data shorter computation time the method automatically creates the stacked trace the stacked trace always shows the events at their exact intercept time Development proposal The computer program in its present form is completely functional, is optimized for Pentium based computers and has been successfully used for production purposes, but it would need a user-friendly, interactive graphical interface for general use. A very rudimentary but functional Visual Basic graphical interface has been already developed. For users of UNIX platforms, a UNIX version of the program would be required. We are looking for the support of the oil and gas industry for the development of these interfaces. We intend to include a whole arsenal of different filters in the package (including a very fast linear Radon transform) which can be used in conjunction with the multiple filter. All these filters have already been coded, optimized and tested in batch processes. We estimate that the completion of the Visual Basic version for Windows 95 and Windows NT operating systems would require 6 months development time at a total cost of $ 60,000. The development of the UNIX version would require 9 months and $ 90,000. We are absolutely flexible in working out the contribution-benefit arrangements with interested companies. We are prepared to supply this software product, or other data processing services, to companies that fund this project on a 3 for 2 basis. For example, if a company provides $10,000 in funding, they would receive $ 15,000 worth of software product or data processing services in return. We believe the value of the software product resulting from the Visual Basic version for Windows 95 and Windows NT operating system would be $10,000. Also, we would appreciate and honour any specific requests regarding features of the program to address individual problems or specific existing installations of processing software. Technical presentation We will give a technical presentation of the software, including hands-on computer demo for those interested, on July 15, 1997, from 11:30 a.m. to 1:30 p.m.
	For further information please contact:	Dr. George Adler, Adler Mathematical Ltd. phone: (403) 239-5883 fax: (403) 262-3748 Larry Mewhort, Husky Oil Operations Ltd. phone: (403) 298-6412
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