The SPWLA Permian Basin Chapter

Technical Lunch and Learn
Tuesday, February 27, 2024 at 11:30 - 1:00 PM CST
Bush Convention Center
Downstairs Meeting Rooms

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“Flow or no Flow: How Geological Influences Effect Wellbore Designs in Over-Pressured Injection Intervals
By: Kelsey Call and Dylan Wiemer

The San Andres and Glorieta formations are prolific injection intervals in the Midland Basin. Recent horizontal wells experience flows within the San Andres/Glorieta in varying degrees due to offset saltwater disposal injection. The overpressure results in casing design changes from 3-string to 4-string, increasing capital expenditure. Depositional characteristics, porosity, permeability of the injection interval as well as injection volumes/perforated intervals and spatial relationships impact the amount of overpressure. This study describes extents of overpressure within the San Andres/Glorieta through integration of well logs, injection/perforation data, core, and 3D seismic to provide geologically constrained deliverables informing operations of flow risk and suggested casing design, predicting future capital expenditure more accurately.

San Andres/Glorieta petrophysical properties were defined by well log and core analysis. Core was used to derive relationships between porosity/permeability from different depositional facies. Stratigraphy was defined in conjunction with log correlation and seismic interpretation, better defining complex geomorphology and depositional environments. Colored Inversion and Similarity seismic attributes were generated assisting stratigraphic interpretation. Pressure plots were generated using water-flood pressure calculations in conjunction with the defined depositional environment. Initial reservoir pressures were determined from recent Step-Rate tests from salt-water disposal wells in the area. Injection volumes, rates and timing were obtained from publicly reported data and averaged by month. Pressure plots were further refined and mapped by utilizing net-to-gross ratios of the injection intervals. A qualitative review of mapped pressure intervals was performed using step-rate tests and recently drilled Diamondback wells in the study area.

The reflux dolomitization was depositional fabric retentive, so depositional facies control porosity and permeability development within the San Andres while cleanest Glorieta intervals are defined by channels. Integrating logging suites and seismic data best defines the San Andres and Glorieta depositional environments. Lower pore pressure from injection wells correspond to San Andres ramp crest as defined by seismic. Combined pressure and geologic maps offer a simple deliverable to suggest casing design requirements to drilling and provide ~450k in capital savings on a per well basis when a 3-string design can be implemented.

Speakers Biographies:
Kelsey Call is a Senior Geologist with Diamondback Energy. She received her B.Sc. in Geological Engineering from Colorado school of Mines and an M. Sc. In Geology from the University of Okahoma.

Dylan Wiemer is a Senior Geophysicist with Diamondback Energy. He received a B.Sc. in Geology from Western Washington University in 2015 and an M.Sc. in Geophysics from the University of Houston in 2018.


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Permian Basin Chapter of the SPWLA

Next Meeting: 
March 26, 2024

Monthly Meetings: 4th Tuesday of Most Months

More Information:
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President: Veronica Montoya 
Vice President of Technology: Chris Smith
Communications: Kate La Fleur
Jennifer Reeves
Sebastian Ramiro-Ramirez