SUPERLOG and LOGFUSION
Petrophysical Software For Larger Projects

INTRODUCTION
During the last few years, we have developed an intelligent log analysis system designed specifically for larger projects. Projects of 300 to 6000 wells have been run successfully with the SUPERLOG and LOGFUSION programs. Database building and computation run times are significantly faster than with any other commercially available program. Costs on real jobs have been as much as 70% lower than conventional analysis methods. Economic benefits can begin when the well count is as low as 50.

Results include the usual petrophysical parameters, such as shale volume, porosity, water saturation, permeability, and hydrocarbon type, as well as quality assessment of each result based on the data sources available. Sums and averages of reservoir properties are generated in both table and map formats. Since many projects also had coal bed methane potential, a separate coal thickness and coal quality count is kept.

Clients may access this software through our consulting service. A client may wish to make use of the SUPERLOG database preparation module by itself, or both the SUPERLOG plus LOGFUSION modules. Our geological, petrophysical, software, and technical staff will work together to see that your data is handled in the most efficient manner possible. You may choose to do the stratigraphic correlations yourself, or let us do it for you.

This software is not yet a commercial product and is not available for sale or license. It is subject to ongoing development. Current effort is being made to extend the petrophysical model to include laminated shaly sands and other difficult or unconventional reservoirs.

SUPERLOG Database
The intelligent database generator is the key to speed and efficiency. Digital TVD log data is loaded from LAS files and scanned for the required log curves. A large alias table permits the program to select the 4 to 10 required curves, re-scale them if needed, and rename them to common internal curve names. Curve names that are not in the alias table are identified and allocated their correct place and priority. If more than one suitable curve is available, the last one found with the highest priority rating is selected as the working curve.

All curves are scanned for valid ranges, nulls, and units conversion problems. A series of units conversion transforms are applied automatically when needed. Wells that do not have sufficient curves for an adequate analysis are rejected. The final selected curves are stored in a searchable Oracle database, called the SUPERLOG file, for use by the LOGFUSION analytical program and the STRATMANAGER stratigraphy program.

LOGFUSION Petrophysical Analysis
This phase occurs in five logical steps that integrates all available data.

1. First, a series of key wells are chosen to cover the project area, usually including all cored wells and others if needed. Only wells with a good suite of logs qualify as key wells. These wells are analyzed individually by an expert petrophysicist in our proprietary META/LOG program. All required mathematical models and parameters are selected and optimized spatially at this time. All log to core calibration is performed in this step. If test or production data is available, log results are also compared to this data. The LOGFUSION parameter set is then tuned to reflect the knowledge gained in this step.

2. Next, the SUPERLOG file is used to make key well and infill cross sections. Here, qualified geologists pick stratigraphic or simulation layers, which are loaded into the STRATMANAGER database. The top and base of a consistent and widespread shale bed must be included as one of the stratigraphic picks, as the LOGFUSION analysis program chooses shale properties for the math models in this zone. This normalizes the logs to obtain reasonable estimates of effective porosity.

3. At the same time, bad log curves, null curves in essential intervals, depth problems (bad KB or non-TVD wells), and spatial gaps are identified from observation of the cross sections and repaired where possible, or removed from the dataset. The cross sections are the key quality control step for the SUPERLOG database.

4. The LOGFUSION program is run against the SUPERLOG database, with results being generated for each of the stratigraphic intervals in the STRATMANAGER file. Net thickness and average porosity maps are generated as a quality control assessment of results. Corrections are made to the STRATMANAGER file or the SUPERLOG file as determined by the geological and petrophysical teams. This step is iterated until a rational set of final maps is obtained. Cutoffs can be varied at this stage to test sensitivity. Results for the key wells are compared to the individual META/LOG results to prove that the LOGFUSION program honours all models and parameters.

5. Selected net pay, net reservoir, or net sand properties, with their associated quality indicator, are then posted for hand contouring, or computer contoured if desired. Result tables are exported for input to volumetric or simulator programs. Depth plots of some or all wells are generated on paper or in PDF format.

INTEGRATION – The Ultimate Goal
This integrated approach to database preparation, reservoir layering, and petrophysical analysis reduces labour enormously, thus reducing elapsed time and total project cost. Since both petrophysicists and geologists are working side by side on the same dataset, cross-discipline communications are enhanced.

Reservoir engineering and simulation benefit from this integration by using a more robust reservoir model, thus reducing the effort required for history matching.