Objective
The aim of the project is to validate, by implementation in an interactive and ready-to-use environment, the integration of several complementary, yet up to now incompatible, velocity estimation and depth imaging techniques such as : reflexion seismic tomography, pre-stack depth migration associated to focusing analysis and velocity determination by coherency analysis.
The resulting software shall provide on a unified hardware and software platform, a comprehensive set of processing and analysis tools dedicated to the estimation of the accurate and detailed structural image of the subsurface required for cost efficient oil exploration.
Several case studies showed that Kirchhof Pre-Stack Migration was in general superior to Finite Difference Migration. High frequencies as well as steeply dipping reflectors better imaged. Kirchhoff focusing analyses were also easier to pick than their finite-difference counterparts.
Iso-X panels and migration velocity scans (Coherency Analysis) proved to be extremely useful to assess the validity of the velocity macro-model.
The project is divided in 5 phases :
PHASE 1- Software Requirement Specifications (SRS)
The SRS will be formalized the following documents :
- a preliminary version of the User Manual providing a comprehensive description of the data input to and output from each module, a precise definition of the operations performed by each module or module component, a concise description of the algorithms used and a complete description of the interaction between the program and the user.
- a preliminary version of the "main" routine of each module. This routine reads, interprets and checks parameters, performs memory allocation and opens data files.
- a complete description of the data and environment files manipulated or created by the program.
PHASE 2 - Design
It shall benefit from the know-how accumulated by the partners in the past three years spent implementing and maintaining a portable, optimized and ready-to-use version of the SG Pre Stack Depth Migration program developed by TOTAL.
For each computational algorithm, whether implemented in an interactive or batch module, the design phase shall generate :
- the explicit description of each component of the algorithm as Fortran subroutines or functions
- the definition of the data structure most appropriate to the effective inplementation of the algorithm.
PHASE 3 - Implementation
The result of the implementation phase is a prototype of each module which provides in a normal production environment the main functions as described in the SRS. Some non-critical options may not be available at that stage. Such a prototype shall be used for test, validation or demonstration purposes.
PHASE 4 - Validation and tests
The main output of this phase is the final version of the code resulting from :
- checking the correctness of the implementation and the validity of the outputs by running a wide variety of tests using synthetic data sets
- implementation of options ignored in the previous phase
- improvements of the user-interface according to the experience gained when using the software in a production environment
- implementation of features absent from the initial specifications but requested by a majority of the users. Properly documented test runs are also part of the output of this phase. At any time after completion of this phase, it should be possible to rerun any of these tests in order to validate a new version of the software.
PHASE 5 - CASE STUDIES
Case studies are a special form of validation where two new conditions are met :
- the data sets are relevant to actual exploration in complex geological areas and enough geological information is available to evaluate quantitatively the new technology in terms of accuracy and reliability.
- most modules and utilities of the SIRIUS package are operational so as to offer a complete range of different
methods as well as the possibility to combine them.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
92500 Rueil Malmaison
France