Seismic Interpretation: Fundamental for Prospect Generation
Seismic data provide us with a response from the subsurface, rather than a model of the subsurface. The challenge for the seismic interpreter is to understand this response, manipulate it in accurate and creative ways in order to model the geology that gave rise to it, and in the process identify drilling targets. This course is designed to help geoscientists meet that challenge by assisting them to: • understand the basics of seismic acquisition and processing, • gain familiarity with qualitative and quantitative aspects of the seismic interpretation process, • utilize various interpretation techniques and tools, • identify and avoid obstacles that limit the reliability of an interpretation, • approach interpretation problems with creativity and perseverance, • apply sound geological reasoning, • build an understanding of how the ingredients can be integrated to constitute a reliable interpretation, • evaluate the risk of exploration success, • journey through the interpretation process to the choice of a drilling location. The course utilizes a comprehensive 2D interpretation exercise based on an actual exploration scenario. This exercise is tackled in different stages throughout the course, helping participants to progressively incorporate the many aspects of the interpretation process, from the early stages of understanding the geological setting and making the stratigraphic correlations, followed by fault interpretation and horizon mapping, through to depth conversion and geological modeling. Additional exercises and case histories complement the classroom instruction, helping participants develop an open and creative mindset to broader exploration objectives as well as to the detail required for prospect generation. This mindset is one that looks for value in contributions from outside the strictly geophysical arena and also incorporates the geological risking process as a means of injecting rigor into the interpretation process. Reinforcing the lessons gained from the major interpretation exercise, the concluding case history provides a further illustration of the integration of the available geotechnical data to achieve a successful outcome.
This is not a survey design course. Survey design is discussed but not covered in detail. After attending this course, the participant will: • Recognize the limitations imposed on a seismic dataset by acquisition and processing specifications; • Identify key mapping horizons and play types in a seismic dataset; • Translate the seismic image into a realistic geological model; • Generate credible hydrocarbon prospects.
Day 1 • The background: Basic geophysics • The preparation: Understanding the geology > Exercise stage 1 • The kick-off: Early observations > Exercise stage 2 • The map: Structural interpretation > Exercise stage 3 Day 2 • The model: Seismic stratigraphy • The detail: Quantitative interpretation > Exercise stage 4 • The risk: Prospect evaluation > Exercise stage 5 • The background: Basic geophysics
All those interested in seismic imagery. The acquisition geophysicist may discover an unfamiliar presentation of familiar concepts. The processing geophysicist may discover the causes of some types of perturbations in seismic images. Likewise, the interpreter may gain understanding of the limitations in seismic images. Those in charge of financing these images may understand better why they are so expensive.
The course is designed especially for early-career geophysicists and geologists as well as students in geoscience disciplines. It will also benefit other professionals involved in oil and gas exploration, particularly engineers and managers who wish to gain a better understanding of the role of seismic data in identifying drilling targets and to make a more informed assessment of the risk associated the decision to drill an exploration well.
About the Instructor
Dean Powell acquired a Bachelor Degree in Applied Science from the Queensland University of Technology at the end of the 1960s. He then began his geophysical career with a Chevron affiliate in West Australia, gaining extensive experience in the acquisition, processing and interpretation of seismic data. Subsequently, he worked as a Perth-based geophysical consultant for many years, providing project management as well as technical services on exploration and development projects in Vietnam, New Zealand and in many of Australia’s sedimentary basins. During the first decade of this century Dean was employed as a Principal Geophysicist with Origin Energy. In this capacity he supervised 2D and 3D seismic acquisition and processing projects, although his main responsibility was the interpretation and mapping of seismic data. Dean provided regional and prospect-scale mapping for exploration in many onshore and offshore regions in Western Australia and other parts of Australia, as well as in Indonesia, Malaysia, New Zealand and Vietnam. In 2013 Dean resumed his consultancy role, and has been engaged in the provision of seismic acquisition, processing and interpretation services relating to conventional and unconventional prospect generation as well as field development in a number of Australian basins and in the Timor Sea. Much of Dean’s experience has been in poorer data quality areas, enabling Dean to develop particular expertise in the interpretation of poor quality datasets. Over the years, drilling on the basis of Dean’s prospect mapping has, to date, resulted in more than a dozen commercially successful wildcat and near-field oil and gas discoveries.