Abstract

Produced water management has become one of the biggest costs and risks of upstream energy production, revealing the void of complete, accurate models that map and characterize formations for saltwater disposal and their spatial relationship to geologic faults, which together may be associated with induced seismicity risks. Operators usually rely on permitted intervals and formations to make saltwater disposal well (SWD) design and planning decisions. But these permit data are inherently inaccurate, as permit filers seek to maximize approved intervals for disposal that they rarely use in practice. Operators also rarely have insight into the designs and activities of their vendors' and neighbors' SWDs, which are important for assessing induced seismicity risks, causes and liabilities. The industry needs better data to manage the safety, reliability and cost of saltwater disposal design, investment, and operations.

To solve this problem across the entire Permian Basin region, we built a data modeling system that identifies exactly which formations every SWD in the Permian Basin is injecting fluids into, further integrating current and historical injection volumes, pressures, geologic faults, hydraulic fracturing activities, and seismic events.

True stratigraphic horizons are used to estimate disposal plumes and subsurface pressure capacities. True producing formations can be used in calculating the impact of lateral length, adjacency, formation, and time on production and on parent-child relationships. Land parcel ownership, wellbore architecture, permits, faults, and geologic formations were compiled and interpreted for geographic and geologic targets. Geologic formation was interpreted by intersecting wellbore architecture with gridded stratigraphic horizons and isopach maps. Over 800,000 well-based formation records were used to create a 3D subsurface model of 42 formations and 1,537 faults in the Permian. Formation records were normalized to match custom stratigraphic columns designed for operators. Stratigraphy, structure, and geographic boundaries were reinforced and corrected by integrating regulatory databases and digitizing peer-reviewed maps. Faults were interpreted and added to a database featuring 13 different resources. Each fault was identified for its formation of occurrence, strike, dip, and age.

Geologic summaries, formation properties, structural surface images, and boundary maps are featured with wellbore injection and production locations and histories and seismic events in a 3D geospatial visualization platform. RRC seismic review guidelines are applied to generate seismic review flags.

1) Operators can assess their risk and liability for induced seismicity from third-party vendor SWDs. These may be operated at different standard than the operator's own wells or might be out of compliance.

2) SWD owners can assess potential risk for induced seismicity from all disposal assets as well as frac operations in a region to identify possible sources of seismic events, thereby mitigating claims against their own assets and operations.

3) Companies planning new disposal wells can evaluate performance, cost, and risk tradeoffs for any set of injection formations in any geography of interest, thereby making better well design and permitting decisions.

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