Seismic Reflection Data: Acquisition and Processing

Undergraduate course

Course description

Objectives and Content

Objectives:
The seismic reflection method is one of the main tools used by geophysicists to probe the Earth¿s crust and uppermost mantle. The goal of this course is to provide students with an overview of how seismic reflection data are collected and processed to form high-resolution images of the subsurface. Upon completing the course, students will be able to understand the entire process that goes into generating the seismic sections they may come across during their career, either in the industry or in academic research. They will have acquired a critical understanding of the strengths and limitations of these images, and will be able to use this knowledge to guide their interpretation of seismic sections.

Content:
The course is divided into two parts. Part I introduces a theoretical basis in signal processing and seismic wave propagation. It then builds on this knowledge to describe the common processing steps used to transform raw seismic data into 2-D images and to estimate seismic velocities of the subsurface. Part II is concerned with the acquisition of seismic data. It provides an overview of the seismic instrumentation used in both marine and land surveys, and describes how these instruments (both sources and receivers) can be arranged optimally to ensure the collection of high-quality data.

Learning Outcomes

On completion of the course the student should have the following learning outcomes defined in terms of knowledge, skills and general competence:

Knowledge
The student can

  • explain key concepts of time series analysis and digital signal processing: frequency, phase, amplitude, Fourier series, Fourier transform, aliasing, filtering
  • explain basic concepts of seismic wave propagation: P-waves, S-waves, elastic constants, reflection, refraction, attenuation
  • explain the processing sequence that leads to the generation of 2-D seismic sections: trace gathers, NMO stacking, velocity analysis, migration
  • describe the various types of instruments used for seismic data acquisition and explain how these instruments work
  • explain key concepts associated with seismic survey design and data quality: bubble pulse, ghost, directivity, and signal-to-noise ratio (SNR)

Skills
The student

  • can carry out basic operation in time series analysis and digital signal processing: compute frequency, phase and time shift of a sinusoid; convolve and correlate two time signals; apply the sampling theorem
  • can compute ray paths, travel times and amplitudes of seismic waves propagating in simple layered media, and assess the resolving power of these waves as a function of their dominant frequency
  • can carry out velocity analysis on simple CMP gathers
  • is able to plan simple and efficient surveys combining various seismic techniques

General competence
The student

  • has acquired general working knowledge of time series analysis and digital signal processing that is applicable to other scientific disciplines
  • has acquired a critical understanding of the importance of selecting the right instruments and designing surveys optimally to ensure the collection of the highest possible quality data
  • can critically evaluate the strengths and weaknesses of seismic profiles based on how the data are collected and processed
  • has acquired basic knowledge in Health, Safety and Environment (HSE) issues relevant for seismic data acquisition
  • has demonstrated competence in scientific ethics and the ability to work independently and as part of a team

Semester of Instruction

Autumn
Access to the Course
Access to the course requires admission to a program of study at The Faculty of Mathematics and Natural Sciences.
Teaching and learning methods

Part I: data processing (6 weeks)

Lectures, 4 hours/week

Supervised exercises, 2 hours/week

Part II: data acquisition (6 weeks)

Lectures and e-modules, 4 hours/week

Compulsory Assignments and Attendance
The students must complete and hand in two problem sets (one for each part of the course) in order to be allowed to take the final exam. These problem sets are only valid for the semester when the course is taught and the following semester.
Forms of Assessment
The forms of assessment are:
  • Problem sets, 40% of total grade.
  • Written examination (4 hours), 60% of total grade.
  • A passing grade ( > F ) in both the problem sets and the exam is required to pass the course.
Grading Scale
The grading scale used is A to F. Grade A is the highest passing grade in the grading scale, grade F is a fail.
Assessment Semester
Examination both spring semester and autumn semester. In semesters without teaching the examination will be arranged at the beginning of the semester.
Reading List
The reading list will be available within June 1st for the autumn semester and Deecember 1st for the spring semester.
Course Evaluation
The course will be evaluated by the students in accordance with the quality assurance system at UiB and the department.
Examination Support Material
Non-programmable calculator, according to the faculty regulations.
Programme Committee
The Programme Committee is responsible for the content, structure and quality of the study programme and courses.
Course Coordinator
The course coordinator and administrative contact person can be found on Mitt UiB, or you may contact studierettleiar@geo.uib.no
Course Administrator
The Faculty for Mathematics and Natural Sciences, Department of Earth Science has the administrative responsibility for the course and program.