Speaker: Andrew Lewis, Vice President of Geoscience at Fairfield Geotechnologies
Subject: A Case Study on the Emergence of the Barnett Shale in the Midland Basin, Ector County, Texas
Abstract: This study focuses on technological applications and results of a Barnett shale drilling program in Ector County, TX. The emergence of significant hydrocarbon production from the Barnett shale is occurring along the transition from the Central Basin Platform into the Midland Basin primarily in Andrews and Ector counties and extending eastward. This study looks back on five wells drilled and completed in the Barnett formation in Ector County, Texas between September 2021 and November 2023 with the utilization of seismic and its integration with limited geologic control. High trace density (HTD) 3D seismic data measured while drilling (MWD) gamma ray logs and mud logs are used in conjunction with production data to evaluate well performance.
Each well in this drilling program utilized HTD 3D seismic data. However, while these wells were being planned and drilled, post-stack time migration (PoSTM) data and eventually pre-stack time migration (PSTM) data were the only available imaged datasets. This study looks back at each well in this program using a pre-stack depth migration (PSDM) image of the same data that benefits from a detailed velocity model produced using time-lag full waveform inversion (FWI). This velocity model and a pseudo-density model generated from it are used as the background trend for a post-stack simultaneous inversion to acoustic impedance. Available MWDs and mud logs are overlaid on these data to assess well planning and reservoir quality in these Lower Barnett Shale wells.
An example of the observations in this study is derived from the first well in this program, the Sweet Melissa. Upon analysis of the PoSTM seismic data, this well was repositioned about 800 ft to the southwest to mitigate the lateral’s traverse across a potentially faulted structure. As a result, this well managed to be drilled longer than planned with a total lateral section of 10,155 ft. The first 12 months of production resulted in 220,155 BOE with an 80% oil cut. The estimated ultimate recovery for this well is 1.2M barrels of oil and 1.8 BCF of gas. The lateral wellbore tracks the Barnett structure seen in the PSDM image to the degree that this well stayed within a 25 ft thick target zone despite encountering over 500 ft vertical drop midway through the lateral over a 1-mile distance.
This case study illustrates the impact that HTD 3D seismic data has on an ongoing drilling program in the Barnett shale. The ability to plan for and respond to rapid structural changes of a relatively thin target zone when there are not many corollary wells in proximity impacts the positive economics of this asset development. High quality data acquisition, processing, and geologic characterization of HTD 3D seismic data are significant factors in the emergence and economic success of the Barnett shale in the Midland Basin.
Bio: Andrew has 16 years of experience as an energy industry professional. He graduated with an M.Sc. in Geophysics from the University of Houston in 2012 and with an Executive MBA from Texas A&M’s Mays School of Business in 2020. As Vice President of Geoscience at Fairfield Geotechnologies, Andrew works with his customers, team, and vendors to create fit for purpose products. He is responsible for the products that comprise Fairfield’s multi-client seismic data library. He leverages this library along with technical partnerships to showcase the value of seismic data. His business acumen and integrated technical background in energy geoscience enable him to conceptualize, develop, and commercialize solutions that result in data-driven decisions for Fairfield’s customers. He is passionate about creating a sustainable future for energy, and continuously works towards developing solutions that are both environmentally friendly and socially responsible.