Abstract
Methane produced from coalbeds is a developing reservoir in the San Juan basin of Colorado and New Mexico. Most of the evaluation of this resource is being done by coring and testing. A cost-effective method to evaluate untested coalbeds would include using wireline logs already run through the coalbeds to assist in the evaluation process. Core analysis and production tests are essential information to use with log analysis to make meaningful evaluations from wireline logs.
This study examines 17 wells drilled in the northeastern part of the San Juan basin. These wells were drilled to produce gas from the Pictured Cliff sandstone, with the Fruitland Coal as a secondary pay zone. The objective of this study was to determine the resource potential of the Fruitland coalbeds using the available log, core and production data. The proximate analysis data from a well in which a coal core was cut was used to calibrate the log analysis in the study area. Measured gas content data was used to calibrate the algorithm which calculated gas content from wireline data. Net coal thickness, igneous intrusive thickness, productivity potential, coal tonage per acre, average gas content and gas content per acre are the results of this study. They are contoured to highlight the most probable area in the township to pursue coalbed methane development.
