FIELD STUDIES

Are you selling valuable assets or failing to realize the potential of your assets?

Before you sell a field, the field should be reviewed to identify the remaining potential and value. Or if you have recently purchased one it must be evaluated thoroughly to realize its full potential.

Perhaps, we can help. Subsurface Consultants has synergistic teams of engineers, geologists, geophysicists and technicians that work together to incorporate all information and disciplines in evaluating the remaining reserve potential of a prospect, property or field. Of course, these teams put into practice what we teach in our subsurface mapping and engineering training programs.

It is economically rewarding to look for oil and gas reserves in mature fields. We recently completed a number of major field studies of fields that were discovered in the early 60's and that had experienced several phases of redevelopment. After almost 30 years of production, 15 to 20 percent of the ultimate hydrocarbon potential in the developed reservoirs remain to be produced and additional potential may be discovered in untested fault blocks and horizons and areas updip of lost wells. We increased the proven reserve volume in all fields an average of about 10 percent. One company we have talked to is re-evaluating one of their mature fields and has already recognized an increase of 20 percent in the proved reserves.

APPLIED PETROLEUM ENGINEERING FOR THE NON-PETROLEUM ENGINEER

Subsurface Consultants & Associates, Inc. will conduct its "Applied Petroleum Engineering for the Non-Petroleum Engineer" course August 29, 1991, in Houston, Texas and November 14, 1991, in Dallas, Texas. This course is designed for the non-petroleum engineer and covers basic petroleum engineering in laymen's terms and provides the non-petroleum engineer usable techniques to evaluate oil and gas reserves using comparative, volumetric and performance techniques. The course focuses on using, not developing equations and techniques. This is a full day, intensive course in which the attendees learn by doing. Th'e course material is included in a course manual with explanations, graphs, charts, calculation forms and examples for future use' and reference.

This course is an outgrowth and updated version of petroleum engineering training seminars previously conducted by Daniel J. Tearpock, co-author of the new and highly acclaimed book, "Applied Subsurface Geological Mapping", and Hines Austin, petroleum engineer, engineering manager, trainer and consultant. The course is also conducted in-house over two days. The two day version expands on the course material and includes more hands on techniques.

EQUAL-SPACED CONTOURING METHOD - QLT'S

One of the first Quick Look Techniques to apply when evaluating a prospect is the method used to contour the map (mechanical, equal-spaced, parallel or interpretive). Many prospect maps are prepared using an equalspaced contouring method. Of all the contouring methods available (Bishop 1960; Tearpock and Bischke 1991), the equalspaced method results in the most optimistic structural interpretation. This method assumes a slope of uniform dip over a general area mapped.

The use of the equal-spaced method often results in unrealistic structure maps (Figure 1) with highs looking like bubble shaped structures and lows portrayed as having sharp cusps. Compare the maps shown in Figures 2a and 2b. Figure 2a is a prospect map showing three proposed locations updip of existing wells. Notice that the map has been prepared using the equalspaced contouring method which shows untested highs adjacent to existing wells (the elusive high that always escapes penetration of the drillbit).

Are the three prospective highs shown in Figure 2a real or the result of the mapping technique? Figure 2b is an alternate interpretation using the same well data, but an interpretive contouring method which allows the mapper to incorporate his experience, understanding of the structural and depositional geology of the area, three dimensional geometry, imagination and skill to prepare a geologically reasonable interpretation. Notice that in Figure 2b, there is 1, not 3 prospective locations.

No one can really develop a correct interpretation of the subsurface with the same accuracy as a typographic map. What is more important is to develop the most reasonable and realistic interpretation of the subsurface with the available data.