Equity Determinations

Netherland, Sewell & Associates, Inc. (NSAI) has conducted reserves certifications, technical studies, economic evaluations, and advisory work for both onshore and offshore fields throughout the world. We use an integrated technical evaluation approach encompassing reservoir engineering, geological, geophysical, petrophysical, and operational engineering disciplines. Our reports and the underlying evaluations are highly respected by the industry and financial community. The unmatched resources, experience, and reputation of NSAI make us uniquely qualified to resolve equity disputes.

Our clients expect quality and integrity. We demand it.

We have accumulated extensive experience with equity determinations in recent years. This work typically consists of an entirely independent evaluation of original oil- and gas-in-place and recoverable reserves from within and across lease boundaries to determine equity ownership of current and produced volumes. Our preliminary reports, rebuttal documents, and final reports typically consist of extensive text and exhibits describing our methodologies, technical procedures, interpretations, and resolutions. All interpreted geological, petrophysical, and engineering data can be provided to the equity interest owners in digital format.

To talk to one of our experts regarding an Equity Determination please call Scott Frost or Dan Walker in our Dallas office at 214-969-5401, or click here for an on-line option.

Listed below are a few projects to illustrate our experience:
  • Performed third-party expert resolution of referred matters of disagreement for the second equity redetermination of Snorre Field on behalf of a consortium of 9 companies. Snorre Field is located offshore Norway on the western margin of the North Viking Graben and produces undersaturated oil from Upper Triassic to Lower Jurassic aged fluvial sandstones. The field is a complex of tilted fault blocks truncated angularly below the Base Cretaceous Unconformity. Our analysis included a completely independent seismic interpretation, multiple models and sensitivities to depth conversion, stratigraphic interpretation, construction of an independent 3-D reservoir model, and multiple, independent adjustments/refinements of the reservoir simulation models.
  • Performed third-party resolution of the second equity redetermination for Markham Field, North Sea, on behalf of a consortium of 10 companies, the Kingdom of the Netherlands, and the United Kingdom of Great Britain and Northern Ireland. Matters referred for expert resolution included fault interpretations, seismic time-to-depth conversions, reservoir mapping, formation evaluation, deviated well corrections, and resolving distributions of oil-water contacts. Our analysis included seismic interpretation, seismic ray tracing and structural analysis, depth conversion, stratigraphic modeling, and reservoir mapping. Assessed the regional and field level stratigraphy, depositional and tectonic history, and petrophysical characteristics of the Rotliegendes and Silverpit Formations.
  • Performed equity finalization studies for the Department of Energy and Chevron U.S.A. Production Company on all zones (4 separate equity determinations) in the Naval Petroleum Reserve No. 1 (Elk Hills Field), Kern County, California. Elk Hills Field comprises over 3,000 wells in 4 major intervals that include 64 producing horizons. Depositional environments range from distal and proximal turbidites to fluvial deltaic clastic reservoirs. The database of well logs and production history ranged in age from early 1900s to recent time. The analysis included independent interpretation of structure, stratigraphy, and petrophysics. Reservoir drainage models included reservoir simulation and production history matching.
  • Served as third-party expert for equity resolution of the Maui Field recoverable gas reserves located offshore New Zealand. This work was conducted on behalf of the gas seller and gas buyer consortiums. Analysis included alternative interpretations to the shallow marine Eocene-aged reservoir layers, 3-D seismic interpretation of faults and horizons, multi-layer seismic ray tracing and depth conversions, petrophysical modeling, probabilistic reservoir property modeling, investigation of capital costs associated with drilling and completion opportunities, and generating an economic model incorporating estimates of recovery efficiency, product flowstreams, project timing, capital and operating costs, product pricing, and contract terms.
  • Performed a geophysical, geological, and engineering study in conjunction with serving as a third party expert for Shell, BP, Exxon, and Conoco in an equity determination of the Ursa project, deepwater Gulf of Mexico. The field produces from multiple Miocene to Pliocene turbidite sand intervals deposited within a mini-salt basin. We evaluated 15 reservoir zones by use of seismic tuning curves and seismic amplitudes calibrated with well log data. Reservoir maps for each interval were constructed to determine volumes and equity shares.
  • Completed an equity determination for the Block CI-11 Contract Area offshore Cote d’Ivoire, including the Lion and Panther Fields, on behalf of Ocean Energy, International Finance Corporation, and Petroci. Reservoirs consist of Albian- to Santonian-age turbidite sands with reservoir traps consisting of rotated fault blocks and stratigraphic pinchouts. The work consisted of an independent assessment of in-place and recoverable oil and gas. We conducted an integrated study incorporating 3-D seismic, petrophysical analysis, fluid property simulation, material balance, reservoir mapping and volumetrics, and decline curve analysis.
  • Conducted technical analysis of 22 onshore gas fields in Germany and testified as a technical expert before an arbitration panel in a confidential dispute involving several major oil companies. This work involved conducting several development scenarios under various economic models to determine historic and future EUR. Procedures were not highly prescribed; production and field data were supplied from which we produced our independent analysis. This work was conducted on behalf of two major oil companies and resulted in a favorable ruling on their behalf.