Geophysical Studies
DeGolyer and MacNaughton deploys the industry’s most sophisticated technology to assist its clients with their exploration and development needs. Its geoscientists are familiar with virtually every oil producing basin in the world, including unconventional reservoirs, both onshore and offshore. This knowledge enables D&M to provide clients with informed and relevant advice and study results. Our co-founder, Everette DeGolyer, was one of the early pioneers in the use of applied geophysics for exploration and development, and D&M has enriched that legacy with its ongoing work in this discipline.
D&M has geophysical experience in virtually every type of depositional and structural setting, including settings where many of the largest recent discoveries have been made, such as deepwater environments worldwide, subsalt reservoirs in Brazil and West Africa, and domestic and international unconventional reservoirs. The firm’s capabilities include:
- Two-Dimensional(2D) and Three-Dimensional(3D) studies
- Seismic reservoir characterization
- Basin evaluation
- Direct hydrocarbon indicator evaluation
- Seismic attribute analysis
- AVO/AVA analysis
- Post-stack and pre-stack inversion
- Rock physics
- Vertical seismic profile (VSP) analysis
- Velocity model building
- Data processing workflow design and QC
- Acquisition design
- Seismic workstation data management
D&M uses a multi-disciplinary approach in serving clients. Its geophysicists work closely with the firm’s other petroleum experts in the fields of geology, petrophysics and engineering to ensure a fully integrated review.
Field Studies
A North African client recently acquired a very large 3D-data set that covered one of the largest gas fields in the world. The client engaged D&M to perform a joint full field seismic interpretation study with the client’s staff that could be used as the structural model for the geologic and dynamic model of the field. This field had several decades of production and hundreds of wells. The close collaboration with the client was invaluable to the study and resulted in an improved product.
The joint geophysical interpretation included:
- Verification of well locations using satellite photos
- Geophysical database organization and project creation
- Seismic-to-well calibration
- Horizon interpretation of seven different reflectors
- Generation and analysis of horizon attributes
- Generation and analysis of geometric volume attributes, such as maximum curvature and dip of maximum similarity
- Analysis and integration of seismic processing velocity information into a full-field depth conversion
- Generation of post-stack seismic inversion volume
The resulting depth structure maps and seismic inversion cube were incorporated into a full-field geological model that was used to create a full field dynamic model. This model will be the basis for future development of this world-class gas field.
Reserves and Resources Reports
An international client approached D&M to provide a reserves report on a trend of deepwater discoveries off the coast of Africa. The client needed a report for an internal appraisal of the discoveries. The report would be used for financing purposes. Because the client was not the operator of the fields, it engaged D&M in order to obtain an independent view of the operator’s technical work.
The evaluation of these fields was highly dependent on interpretations of the 3D-seismic data covering the accumulations. The fields covered a large area and generally had only one or two wells in each individual accumulation.
The 3D-data set, attribute volumes, time-depth information, well information and the operator’s interpretations were provided to D&M’s geophysicists. Using this information, D&M:
- Evaluated the operator interpretation, adjusting it where warranted
- Evaluated the ability of horizon attributes, such as amplitude, to predict fluid type and lithology
- Evaluated the operator’s historical predictions of net pay and depth to reservoir prior to drilling
- Examined the data to identify any potential breaks in reservoir continuity due to faulting or changes in stratigraphy
D&M’s evaluation clarified where the uncertainties were and formed the basis of classifying the contingent resources into areas of low, medium and high confidence. These areal classifications were then integrated with the petrophysical analysis, geologic interpretations and engineering analysis to estimate 1C, 2C and 3C contingent resources using SPE-PRMS guidelines.