Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Résumé Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Gentzis, T. Articles by Santillan, M. Search for Related Content GeoRef GeoRef Citation

Horizontal degasification and characterization of coals in the Sabinas Sub-basin, Mexico: implications for CBM production

Formerly with CDX Gas, LLC Suite 1060, 1801 Broadway Denver, CO 80202, USA
CDX Gas, LLC Suite 190, 5485 Beltline Road Dallas, TX 75254, USA
Minerales Monclova S.A. de C.V., Prol. Pdte. Cardenas S/N, Apartado Postal No. 47, C.P. 26350, Palau, Coahuila, Mexico
CDX Canada, Co. Suite 1210, 606 - 4th Street SW Calgary, AB T2P 1T1, Canada

The Sabinas sub-basin in northern Mexico contains gassy coals in the Upper Cretaceous Los Olmos Formation, based on both historical evidence and current desorption testing. The "Double Seam" coal is present at shallow depth (<500 m), has high vitrinite content (>86 vol%), is well-cleated, shows high diffusivity [average tau () value is 56 hours] and has high natural fracture permeability (>30 mD) in the minesites. The coal averages 2.2 m in thickness but has a high ash content (32 wt%). A tonstein band is present in the middle of the Double Seam, consisting of vitrinite and inertinite embedded in a matrix of fine clays and quartz. Average desorbed gas content of this medium-volatile bituminous coal ³/g). Maximum methane adsorption at an equivalent (Ro_max = 1.30%) is highest in Mine V (Esmeralda Mine at >9.0 cm depth of 300 m is 15 cm³/g (as-received basis; arb). Coal bed methane is mainly methane (98%) with heating value of 38.21 MJ/m³ (1026 Btu/ft³). The coal is under-pressured and reported to be dry, with possibly free gas in the cleat/fracture system and absence of discrete mineralization. In-seam horizontal drilling prior to longwall mining has resulted in the significant reduction of in-situ gas contents and in an increase of mined coal production per shift. The Sabinas sub-basin coals are suitable for a full-scale coal bed methane (CBM) development using in-seam single horizontal and multi-lateral horizontal drilling. Similarities, but also differences, exist between the Sabinas coals in Mexico and the same coals in the Maverick Basin, Texas.