July 29, 1999

Dear Landmark Customer,

Landmark is committed to assisting its clients in their Y2K compliance efforts. In fact, Landmark has been at the forefront in preparation for the year 2000, having announced earlier this year the completion of its active Y2K testing and readiness program for its major product lines.

In regards to digitizing software, Landmark has worked with its long-time third party solution provider, Neuralog, Inc., to assure that a digitizing application is available to its customers and the industry in anticipation of the year 2000. Neuralog is the leader in automated tools for integrating paper and digital data of maps and well logs. NeuraMap and NeuraLog are the fastest, most accurate digitizing solutions available for the E&P industry. The Y2K versions of NeuraMap and NeuraLog are now released.

NeuraMap rapidly digitizes geological and cultural map data as well as seismic and geological cross section data from scanned images for immediate output to the Landmark suite of applications.

"NeuraMap is a milestone to the map digitizing industry…Because of its many features, it has become a work-flow shoe-in." --Thomas Gamwell, Phillips Petroleum.

NeuraLog quickly creates digital well log data from scanned well log images. Well log data can be generated in LAS format or sent directly to OpenWorks for use in StratWorks or PetroWorks.

"I calculate that digitizing time was reduced to one-quarter of what it would have taken on a traditional digitizing board … the cost of work was far less than sending the data out of the office to be done." --Melissa Sonnen, North Central Oil Corp.

Landmark and Neuralog are offering a special discount for the Y2K versions of the digitizing applications. Now through September 30th, 1999, Landmark and Neuralog have arranged to make the software available to all Landmark customers for 20% off list prices! A 10% discount will apply between October 1st and December 31st, 1999. Scanners are discounted 10% during this period. THAT TRANSLATES INTO BIG SAVINGS! Please refer to the enclosed pricing schedule.

To receive additional information on NeuraLog and NeuraMap, please call the Neuralog Sales department at 1-800-364-8728 ext. 17 or www.neuralog.com.

Sincerely,

Leslie Mashburn,
Product Manager
Landmark Graphics Corporation

Robert Best,
President
Neuralog Incorporated

NOTE: Statements made to you in this letter are subject to the Year 2000 Information and Readiness Disclosure Act (105 U.S.C. 2392). In the case of a dispute, this Act may reduce your legal rights regarding the use of any such statements, unless otherwise specified by your license agreement or tariff.