WorldWide Drilling Resource

17 WorldWide Drilling Resource ® SEPTEMBER 2014 Revival in the San Juan Basin Adapted from an Article by Louise S. Durham Appearing in The American Association of Petroleum Geologists’ Explorer As the saying goes, “Everything old is new again.” These days, this phrase is certainly true in the oil patch. Producing zones thought to be long- dead are coming back to life with the assistance of advanced technologies like horizontal drilling and new seismic techniques. The Permian Basin in west Texas is one of the best-known “new again” regions; however, a low profile revival is taking place in the San Juan Basin in the Four Corners area straddling the borders of New Mexico, Colorado, Arizona, and Utah. WPx Energy has been working in the basin for many years. Sophie Berglund, a senior geologist at WPx Energy said the renewed action there is the result of completions in uncon- ventional reservoirs in the Mancos Shale and Gallup Sandstone Formations. For decades, legacy drilling and completion operations targeted conven- tional reservoirs in these formations. Though vertical drilling achieved highly successful production in the basin, pro- gressive technology is now being applied to pay zones which were previously bypassed, and this has made all the difference. “The San Juan is a big area, and there are some interesting changes in how the reservoir changes and the maturity of the source rock changes to make distinct plays,” said Berglund. “Serendipitously, Mancos source rock changes phase from volatile oil to dry gas coincident to changes in the nature of the reservoir.” According to Ron Broadhead, sen- ior petroleum geologist at the New Mexico Bureau of Geology and Mineral Resources, the Manco has historically been viewed as a source rock of oil and natural gas, and as a seal for con- ventional reservoirs. In 2010, WPx Energy made a con- siderable natural gas discovery in the Mancos, but dry gas was of little inter- est at the time. The company decided to explore the wet gas/condensate and oil windows in the central and southern parts of the San Juan Basin instead, referred to as the Gallup Sandstone. After drilling four vertical explorato- ry wells, a major oil discovery was con- firmed by the company. Since then, WPx Energy has drilled an additional 12 wells, and has 29 more planned for this year. For current and future wells, horizontal drilling and hydraulic fractur- ing have become the technologies of choice for continued success in the Gallup. Avivamiento en la Cuenca de San Juan Adaptado de un artículo de Louise S. Durham que forma parte de la Asociación Americana de Geólogos Exploradores Petroleros Como dice el refrán, “Todo lo viejo es nuevo otra vez.” En estos días, esta frase es muy cierta en el ambiente petrolero. Zonas productoras que se creían muertas hace mucho tiempo, están volviendo a la vida con la ayuda de tec- nologías avanzadas, como la perforación horizontal y nuevas técnicas sísmicas. La cuenca Pérmica, en el oeste de Texas es una de las regiones mas cono- cidas como “nueva otra vez”; Sin embar- go, un avivamiento de bajo perfil se está llevando a cabo en la cuenca de San Juan en la zona de las Cuatro Esquinas entre las fronteras de Nuevo México, Colorado, Arizona y Utah. WPx Energy ha estado trabajando en la cuenca durante muchos años. Sophie Berglund, una geóloga experta de WPx Energy dijo que la acción re- novada es el resultado de terminaciones en yacimientos no convencionales en la pizarra de Mancos y Formaciones de piedra arenisca de Gallup. Por décadas, los legados de las operaciones de perforación y termi- nación se enfocaron en los depósitos convencionales en estas formaciones. Aunque la perforación vertical logró un gran éxito de producción en la cuenca, la tecnología progresiva está siendo aplicada a pagar zonas que fueron evi- tadas anteriormente, y eso es lo que ha hecho la diferencia. “San Juan es una área grande, y hay algunos cambios interesantes en la manera como cambia el depósito y la madurez de los cambios en las rocas de origen para hacer maniobras distin- tas,” dijo Berglund. “Casualmente, la roca original de Mancos cambia de fase Sunrise in the San Juan Basin. Photo courtesy of WPX Energy. Hector Leos Translator Revival trans cont’d on page 18.