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• NSA has developed TRTT"", a unique, proprietary, non-destructive, ground characterization method that can indicate ground/rock conditions surrounding a tunnel or opening. TRTT"" is a seismic imaging technology that uses reflected seismic signals to indicate changing ground conditions up to 200 ft from a seismic source and receiver array. As seismic energy radiates from its source, a portion of the energy is reflected from the interface of contrasting ground conditions such as faults, fractured rock, water-bearing joints, or changing rock types. The reflected seismic waves are recorded and utilized by NSA's TRTT"' software to calculate and generate 3-D color images that indicate the location and relative severity of these various tground features. NSA was asked to investigate the application of the TRT "^ tomographic imaging system for evaluating the size and shape of the caverns resulting from solution mining. NSA proposed using TRTT"' to perform a test survey for one cavern. The receiver array, consisting of 23 hydrophones spaced at approximately 25 - 40 feet apart, will be lowered into the long tubing string on a 300' offset well to well 29-24. Twenty-three sources, (wireline perforation charges) will be lowered into the long tubing string on well 29-24. The charges will be detonated at elevations corresponding to the elevations of the hydrophones in the adjacent well. A seismograph recorder will record the response of the hydrophones to each source detonation. The seismic data will be interpreted by the TRT software to provide a profile of the cavity between 29-24 and the offset well. • This survey will take up to two days of or ~-site data collection. After data collection is complete, NSA's personnel will process the data, generate images, and prepare a final report. Data processing and report preparation will be completed within four weeks from completion of data collection. Recognizing that the goal of the project is to determine that this ground imaging technology is effective in mapping caverns produced by solution mining, NSA will prepare a final report. The report will contain complete documentation of the test, including study objectives and results, deployment and data collection, data processing and interpretation. Well Fluid Displacement Upon completion of the seismic tests, ASLLP will displace the fluid in well 29- 24 by injecting natural gas on the short string 4'/z" tubing or the 7" casing and recovering the fluid from the 4'/s" long tubing string. The volume of gas and the volume of fluid will be measured. The interface between the gas and the fluid within the cavity will be determined by a temperature profile down the 4'/2" long string on a systematic basis.