Aims and Objectives
An initial meeting should be held to discuss the aims and objectives of the client and the workflows/techniques that the client would like to use on the project. The client should specify the number of wells and area of seismic that they would like to use in the study as well as any comments or concerns about data quality.
During this meeting, it would be useful to receive some background information about the prospect/field such as source rock, reservoir, cap rock, trapping structure, migration pathways and history of the field as this will help Falcongeo to understand a general picture of the area. The discussion about the project should also involve timing of the work, duration of the work, project deadlines, cost of the study and whether the work will be carried out in phases or one time period.
Well Log Data
For each well,Falcon geo will require a LAS file containing the following raw logs (Vp, Vs, RHOB, Gamma Ray, Caliper) and the following Petrophysical curves (Volume, Porosity and Saturation). If Petrophysics is not available for the study wells then Falcongeo can offer this service.
Falcongeo require a deviation survey (ASCII file), a check-shot survey (ASCII file) and formation tops at every well. If there is a composite log, final well report, drilling parameters and PVT report then these would also be useful to Falcongeo for understanding data quality and parameters affecting the well.
If Petrophysics is required in the project then core data (Excel file), mud log data (Tiff file), individual logging runs (Tiff file) and the digital wireline/LWD log data (LAS file) will also be required. The digital wireline/LWD log data can be supplied merged or unmerged.
The following curves are required for the Petrophysics analysis; sonic (compressional and shear), density, gamma ray, caliper, neutron, SP, PEF and resistivity (laterolog/induction).
Definition of Viable Reservoir Intervals
Falcongeo need to understand the criteria that the client uses to consider to be a viable reservoir interval and the reservoir intervals that are of most interest to the client. The client needs to specify the key reservoir intervals and the cut-offs used to define viable reservoir intervals.
For example, in a sandstone reservoir, a default cut-off of PHIE > 0.08 and Vol_Sand > 0.6 may be used to ensure low porosity sand points and shale points are not included in the Gassmann Fluid Substitution process. A minimum reservoir thickness may also be applied to rule out thin sandstone intervals away from the main reservoir working interval.
For each viable reservoir interval in each well,Falcongeo will require formation temperature, formation pressure, salinity, Oil API, GOR and gas gravity data to calculate fluid sets and define the elastic properties of the reservoir fluids.
Fluid Modelling Cases
The default cases for fluid substitution modelling (Gassmann) are the INSITU, 100% Brine, 80% Oil/20% Brine and 90%Gas/10% Brine fluid cases. These fluid cases can be changed or expanded as per the client’s specifications. It is also possible to consider fluid modelling with a variation in oil API properties if relevant to the client – for instance; a heavy oil vs light oil scenario.
For each volume, Falcongeo will require a SEGY file. The volumes expected are:
- Full Stack with EBCDIC headers
- Angle Stacks for at least Near, Mid, and Far
- Migration Velocity if gathers not converted to angles stacks
- Processing Report or at least the processing sequence applied to the data
Horizons and Tops
Falcongeo will require tops (markers) and TWT horizons in ASCII format files.