Oil & Gas Training
and Competency Development

Discipline Geophysics
LevelFoundation
Duration5 Days
Delivery Mechanism Classroom
Print Email

Non-Seismic Geophysical Methods

Seismic data has been the main stay of geophysical interpretation. Although within Quantitative Interpretation it became clear that seismic only showed us one aspect of the subsurface, namely changes in acoustic impedance. This was sufficient for structural interpretation but in the oil and gas industry we are mainly interested in the fluid content of the (reservoir) rocks. From the behaviour of the reflection amplitude with source-receiver offset we can in favourable circumstances also get an idea of the pore-fluids. It is clear that additional data are needed. These additional data can traditionally be found in potential field data (gravity and magnetic data) and recently in electromagnetic data (interestingly enough the oldest exploration tool). Especially in Controlled Source (deep) marine Electro-Magnetic methods can we measure the reservoir resistivity directly which is a direct indicator that it could contain hydrocarbons? On land in remote areas the Magneto-Telluric Method is an efficient exploration tool. However, none of these methods will solve all problems, but in combining them we gain more than just the sum of the individual benefits

  • Agenda
  • Topics
  • Audience
  • Prerequisites
  • Agenda

    Day 1

    Gravity

    • Introduction to Geophysical Methods

    • The role of Non-Seismic Methods in the E& P business

    • Gravity Surveying

    • Determination of contour map anomalies

    • Calculation of gravity responses

    • Determination of Gravity resolution of bodies, anticlines and faults

    • Depth estimation methods: Half-width, Gradient-amplitude

    • Exercises on paper and using computer software

    Day 2

    Magnetics and Electrical Methods

    • Introduction to Magnetic and Electrical methods

    • Gravity and Magnetic signatures

    • (Poisson’s) Relationship between Gravity and Magnetic responses

    • Electrical surveying methods

    • Calculations of resistivity profiles, effective resistivity

    • Exercises on paper and using computer software

    Day 3

    Electrical and Electro-Magnetic (EM) methods

    • EM: diffusion or wave-propagation ?

    • Land EM: TEM surveying

    • MT: surveying & modelling

    • Marine EM:CSEM surveying

    • Calculations of E refraction, MT resolution, EM skin depth & velocity

    • Exercises on paper and using computer software

    Day 4

    CSEM Modeling and Inversion

    • EM Terminology

    • Exercises: CSEM Scripps Modelling: 3 layers

    • Exercises: CSEM Scripps Modelling: 5 layers

    • CSEM & MT: Scripps Occam Inversion

    Day 5

    Time-La

    • Time-Lapse Gravity & Electrical Methods

    • Joint Inversion CSEM & MT

    • Joint Inversion TE & TM

    • Joint Inversion TDEM, AMT, MT

     

  • Topics

    Emphasis in the course will be on active participation in discussions and interaction between participants and with the course instructor. Participants will be divided into teams. Each team in turn will give a summary of the main learning points of the day and design and give a quiz to be presented to and discussed with the participants. The participants will quite actively apply the methods in partly paper-based and partly computer-based exercises to enhance the learning. Also videos will be shown illustrating the methods.

  • Audience

    Geo-scientists, who need to plan multi-geophysical-data acquisition and who need to decide on which data should be acquired for exploration, appraisal and interpretation. Interpreters who need to combine the information contained in the various data sets: seismic, potential field (gravity and magnetic) and electrical and electromagnetic data.

  • Prerequisites

    Awareness of the exploration and appraisal phases in the search for hydrocarbons and some knowledge of seismic acquisition, processing and interpretation.

     

  • Prerequisites

NExT Technical Forum:
Continue your in-class discussion and questions in an online community