Production of hydrocarbons from tight reservoirs has a long history and traces itself back to the end of 19th – beginning of 20th century, when the natural gas production came from low-pressured fractured shales in Appalachian Basin. However, the lack of technology during that time did not allow operators to produce it with the adequate flow rates. It took almost 60 years for the industry to take a second look at these types of reservoirs, when Mitchell Energy & Development Corporation showed an interest in exploration of Barnett shales for gas production.
This interest was a foundation of “shale gas revolution”, which was unfolded 20 years later and brought the tremendous economic success in the development of the unconventional shale plays in the United States.
Initial successful development of unconventional shale plays was due to two major breakthroughs in engineering technology – hydraulic fracture stimulation and horizontal drilling along with advances in a shale gas logging services suite and formation evaluation workflow specifically designed for evaluation of unconventional reservoirs. Since, the unconventional plays are usually the formations, where the source rock, reservoir and trap are continuous and well-defined, the role of geophysics had a more secondary, supportive role in early stages.
However, for continuing success, there is a need to have more technology to be applied to the process. The decade of exploration & development in the unconventional plays showed that there are large variances in the reservoir, both laterally and horizontally, which have a huge impact on production, decline rates and ultimate recoveries. This indicates that a successful drilling campaign in an unconventional shale play should include all pieces of geological, petrophysical, and geophysical information to build a realistic and accurate model of the subsurface.
Application of seismic data information into the evaluation to identify sweet spots in the play makes the development much more successful since the targeted drilling of these sweet spots makes the production more profitable and helps to avoid drilling uneconomical wells.
This case study, targeting Haynesville shale, outlines an integrated approach of petrophysical wellbore formation evaluations with seismic inversion applications to successfully identify and map the sweet spots based on 3-D seismic datasets.
About the Author
Said D. Sadykhov, Geoscience Advisor, Baker Hughes Inc. After graduation in 1993 from Azerbaijan State Oil Academy with MS degree in Geophysics with specialty in seismic exploration, joined SOCAR’s (State Oil Company of the Azerbaijan Republic) Caspian Sea Geophysical Exploration Trust.
In 1995 was nominated to participate in a joint study of hydrocarbon potential of the southern portion of the Caspian Sea, spearheaded by Chevron Overseas Petroleum Inc. (COPI), in San Ramon, CA.
In 1996 joined ExxonMobil Exploration Company in Houston, TX and worked for Caspian project, Russian Regional Evaluation project, and deepwater Nigeria/Gulf of Guinea Regional project.
In 2006 joined Baker Hughes’ Geoscience group where was managing a multi-disciplinary team to support offshore/onshore drilling activities and covering advanced acoustic data processing & interpretation, borehole image data analysis & interpretation, and integration with conventional petrophysical, core data for enhanced reservoir description. Since 2013 is a Geoscience Advisor with the special attention to unconventional plays in North America & worldwide.