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Finding drinking-water reservoirs, mainly located between depths of 800 m to 2000 m, is important in reducing the current deficit supply of drinking water to Mexico City. The acquisition of reflection seismic, the reprocessing of old 2D lines, the reprocessing of well-log data, and the use of gravity data allowed the creation of an earth model of the studied area, consistent with all available geophysical and geologic information, and defined 10 drilling prospects. In addition, based on data-integration results, a deep regional fault named Texcoco-Iztapalapa fault was identified. The seismic-reflection method, combined with interpretation techniques developed and commonly used for oil and gas exploration, can be adapted to drinking-water prospecting.

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Lately, the United States of America has experienced tremendous growth in shale plays development. To date, more than 5,000 wells have been drilled and completed in more than 20 fields. Worldwide, exploration and development of shale plays has also increased. Currently, due to low gas prices, operating companies are shifting resources to explore and develop condensate or oil producing shale plays. In 2010, exploration of gas-rich and possible liquid-rich shale reservoirs began in northern Mexico. The main challenges were to demonstrate the availability of reserves and set the foundation for future development of these plays, with the information gathered in a few exploratory wells. Wells were aimed at the upper cretaceous Eagle Ford formation and at the Jurassic Pimienta formation. As of July 2012, six horizontal exploratory wells were drilled and completed, implementing in four of them a two stage integrated workflow to achieve the objectives set. The drilling stage used a petrophysical and geomechanical static model to identify the most prospective interval in the reservoir, define the best drilling azimuth direction and landing point, and reduce drilling risk. Real-time geosteering was implemented to achieve the targeted navigation window. In the completion stage, a reservoir-centric completion and stimulation software, which integrates petrophysical and geomechanical data, was used to optimize the completion and stimulation design. Results were evaluated using various techniques, including micro seismic monitoring, production history matching, production logging and well testing. This study presents the details of the workflow implemented and the lessons learned in each well. The main lessons learned were: 1. Proper well landing was key to achieving predicted production and booking of reserves; 2. Anisotropic geomechanical models were the most appropriate for simulating hydraulic fracturing treatments; 3. Conventional hydraulic fracturing models do not always represent the behavior of fractures in the unconventional formations evaluated; 4. Production rates along the lateral of the well can vary significantly with single stages producing up to 20% of the total well production. The conclusions and lessons learned in this study have formed the bases and will be important to the subsequent development of the different shale plays in Mexico-and around the world.