AAPG kicks off 100-year anniversary celebration at ACE 2017 in Houston
HOUSTON -- AAPG President-elect Charles Sternbach opened the society’s Annual Convention & Exhibition in Houston on Monday morning, in the Discovery Thinking session, saying that “geology is a science” but “exploration is a business.” In 1917, the AAPG was originally conceived as a “technology transfer” society, with learnings captured in the field translated to paper media and distributed to the geological community for application in analogous situations. Mr. Sternbach said that geology, and the use of geological sciences, still play a vital role in our business, in spite of engineering advances in drilling and hydraulic fracturing. The application of petroleum geology has contributed significantly to the discovery of the 1,000 known super-giant fields (500 Bbbl) around the world, most of which are onshore.
The Discovery Thinking session was launched in 2007, in the spirt of the original AAPG concept, to outline high-level exploration strategies and share successful methodologies. Previous vignettes were highlighted to recognize the accomplishments of more than 100 people, who have participated in these forums. The omage served to acknowledge these successes and recall key lessons learned. One notable item was the Wolfcamp Geology of the Midland and Delaware basins by Jim Henry. This geological study of this Permian formation was a major factor enabling exploration companies to reinvigorate drilling in this mature area and significantly enhance oil production from known hydrocarbon-bearing structures.
Geologic modeling discovers giant gas field. Next, Total geologist Phillippe Mallard presented details on an Andes foothills gas play. Geophysicists determined that the area’s seismic data were poor and would provide little help in delineating the subsurface. However, surface geology was good, and outcrops were used to help develop new structural models.
The new cross-sections showed a thrust-faulted situation, similar to other fields in South America. The section in question was the crested Devonian reservoir at the heart of the anticline under significant faulted overburden. The study also included new Devonian bio-zone definitions. Three models were rendered/devised and superimposed to outline the degree of variance between each hypothesis. The best-fit model was selected, and a directional well was drilled that discovered the giant Incahuasi gas field.
Utica shale update. Two Range Resources geo-scientists (Bill Zagorski and Taylor McClain) gave a tag-team presentation, detailing how commercial production was established in the Utica shale. The pair presented an interesting historical perspective, followed by an in-depth look at how applying a combination of geological sciences defined the Utica’s sweet spot by mapping the lithology of the overburden. According to the team, the tight overlaying formation serves to effectively seal in hydrocarbons and pressure in the Utica. The company used this information to update its production model, which has identified an oil leg on the western edge of the fairway, with the more profitable dry-gas portion (with greater areal extent) on the eastern side of the play.
The modeling and updated mapping techniques led to the completion of two high-flowing Utica gas wells, in Washington County, Pa. The first is estimated to have 15 Bcf EUR, or 2.8 Bcf/1,000 ft of lateral. The second Utica well, brought online with choke management at 13 MMcfd, is projected to have higher EUR than the first well.
During the historical review, it was noted that gas shows were present in the Utica shale in the early 1900s in the general area. But only the use of horizontal drilling techniques and fracing was able to coax commercial volumes of natural gas from the Utica. Although the formation extends north into New York and beyond, the company’s Utica activity is now focused on dry gas production in southwestern Pennsylvania.
Denver basin overview. John Forster, exploration advisor for Whiting Petroleum, gave a brilliant explanation, with detailed mapping of the strategy/results, that defined Redtail Field, A Thermal Anomaly on the Eastern Extension of the Colorado Mineral Belt, Denver Basin, Colorado. The presentation showed how Mr. Forster’s team used a combination of mapping methodologies, that included temperature and resistivity data, to chase production in the Niobrara formation to a successful conclusion.
An example of optimizing horizontal spacing units also was given, called “wine-racking,” by taking a traditional surface-type staggered pattern, then turning it 90° to ensure efficient drainage for all laterals by formation and depth. Finally, in addition to finding/increasing production, the geo-team also contributed to reducing drilling days from 23-30/well, down to just 3.88 days.
Value added. Although AAPG offers many technical sessions, Discovery Thinking forums fill an important gap in how technical and professional skills combine to turn prospects into discoveries. Speakers share personal stories and experiences to bring forward appropriate technical data, and to address questions from the audience.
