Abstract
Advanced Hydrocarbon Stratigraphy (AHS) has been active in the STACK and the SCOOP since 2013 through long term partnerships with companies like Ovinitv and Fairway Resources to help clients better drill and complete their wells while providing unique insights into the petroleum system by analyzing the volatile subsurface fluids entrained in cuttings and core samples though Rock Volatiles Stratigraphy (RVS). Beginning in 2016 with Fairway Resource and then Ovintiv extensive work was done to understand the petroleum system across the Anadarko basin; this was especially important in the NW STACK where the Woodford is immature and long distance migration was need to charge the targeted Mississippian limes of the Meramec and the Osage. Identifying these migration pathways along faults crossed by laterals was not only important in terms of understanding the petroleum system, but also which fault blocks were charged and had better quality reservoir since the emplaced oil had halted diagenesis – this information helped drive completions and acreage utilization decisions. Moving south and deeper into the more mature Woodford the HCs present increase, the water content decreases, and the HC composition changes in ways that can be attributed to continuing maturation. The Miss. limes above these increasingly mature Woodford source rocks show evidence of charging by vertical migration with compositions that suggest charging occurred before induration. After a certain depth the HC trends are lost with only heaviest HC liquids measured still showing the effects of increasing maturity – several portions of the deeper productive Woodford in the Anadarko basin are regions with significant faulting and fracturing and show evidence of past loss of significant quantities of gases and light HCs. That these faults and fracture networks can serve as migration pathways has been observed in laterals where the effects of such features can be better profiled and can be an issue for the productivity of laterals.
Beyond understanding these aspects of the petroleum system, other applications have ranged from examining the prospectivity of the Caney relative to the Woodford and evaluating the effects of offset legacy vertical production on new laterals. We look forward to the opportunity to share these experience and learnings with the Oklahoma City Geological Society this February.
AHS was founded in 1995 by Dr. Michael Smith right up the road in Tulsa, OK. AHS’ previous generation of technology, fluid inclusion volatiles, was sold to ExxonMobil in 1999 and continues to be extensively used in house by XOM. Mike also built, developed, and patented the technology behind fluid inclusion stratigraphy while working at the Amoco Research office in Tulsa in the 1980s. RVS represents a significant advancement on these prior technologies as PDC bit cutters have made modern drill cuttings typically unsuitable to fluid inclusion work – rather RVS works by extracting entrained volatile subsurface fluids preserved in tight poor spaces and unexposed rock surfaces.
RVS uses a gentle vacuum extraction cryo-trap mass spectrometry system where volatile subsurface fluids entrained in rock samples are gently extracted by vacuum (no heat or solvent used) and collected on a liquid nitrogen cooled cryo-trap. After the extraction and collection of the volatiles is completed the cryo-trap is slowly warmed and the released volatiles are then passed to a mass spectrometer as they release sequentially by sublimation point. This process enables the separation, identification, and quantification of the subsurface fluids extracted from the rock samples and is known as Rock Volatiles Stratigraphy (RVS). Direct measurements of 40+ different compounds including the C1-10 HCs, water, CO2, biological by-products, noble gases, stimulation chemicals, sulfides, and several others are made using this technique while the process is repeated on the same rock sample under increasingly strong vacuum conditions providing information on ease of release that can be related back to rock properties.
About the Speaker
Christopher Smith (PhD)
Senior Chemist
Advanced Hydrocarbon Stratigraphy
Christopher Smith has been a Senior Chemist with Advanced Hydrocarbon Stratigraphy (AHS) since January 2019 and moved to Midland in 2022 working on data analysis, instrumentation, client engagements, and business development. Most of his analysis work focuses on the Permian, the Anadarko and Arkoma basins in Oklahoma, the North Slope in Alaska, and the Marcellus. Since 2020 a significant portion of Christopher’s work has been geared toward expanding the uses of AHS’s unique patented technologies into non-traditional fields for AHS beyond oil and gas – these include successful engagements and projects with academia, government, and operators on subsurface studies in carbon capture and sequestration, helium exploration, and geothermal power. Additionally, he has pushed AHS to be involved in scientific studies on permafrost in the Artic and the paleo environment before, during, and after the Chicxulub impact. Prior to working for AHS, he received his PhD in analytical chemistry from the University of Arizona with focuses on instrumentation, data analysis programing, spectroscopy, electrophysiology, surfactants, and surface modification chemistries. He also completed a MA in history at the University of Tulsa as a Henneke Research Fellow in 2012. He completed his undergraduate work cum laude in 2011 with degrees in chemistry, history, and biochemistry also from the University of Tulsa.
Tulsa Geological Society