UK Onshore Field Studies

Petrophysical Analysis of Each Well

NuTech has performed its proprietary NULOOK analytical services over the data to the total logged depth of the well in order to identify the key reservoir parameters, and to qualify and quantify prospective opportunities for both conventional and unconventional plays. Where possible, and the available curve data permits, the analytical services incorporate all aspects of the NULOOK technical analysis. Thus each well will be analysed using:

• NULOOK Textural Vision™
• NULOOK Shale Vision™
• NULOOK Fracture Intensity Vision™
• NUSTIM® GeoTextural Log

The analysis first reviews the total logged intervals for the wells using the NULOOK Textural Vision™ service, which determines the lithology, porosity, permeability and fluid content of each well, identifying hydrocarbon potential in the conventional reservoirs. Further analysis is then undertaken of the unconventional potential in each well using NULOOK Shale Vision™ to assess the hydrocarbon bearing potential of the source rock and NULOOK Fracture Intensity Vision™ to identify the existence of naturally occurring fractures that could aid permeability.

The NULOOK petrophysical analysis has conventional and unconventional parameters for key reservoir criteria modelled on core and cuttings analysis. NuTech has conducted its own independent assessment of samples from core and cuttings over the various shale sequences in each of the basins, which we have used in the establishment and calibration of the key reservoir parameters in the unconventional sequences of each well. The Intellectual Property Rights (IPR) to this analysis belongs to NuTech.

Where existing core or cuttings analysis data as provided by Customers is considered usable, and where this data is used for well calibration in the UK Regional Field Study, the source of the data will not be referenced and it will not be identified by tie points in the outputs.

Field Study & 2D Property Modelling

The project has then taken the results of the petrophysical analysis produced for each well and used our NUVIEW® Field Study 2D & 3D Property Modelling to compare and contrast each well in respect of thickness (see Figure 1) of the prospective unconventional sections, together with mapped reservoir parameters showing clay, TOC, effective porosity, permeability, SW, and STOIP, etc.

The wells are analysed to determine both the areas of greatest productive potential, and those areas that are either not so well-charged in terms of hydrocarbon volume, porosity or permeability, or which are outside the shale play region altogether, and so determine the “hot spots” and reserve potential within the shale play.

Completions Design Modelling

The second build phase of the project utilises our NUSTIM Pro Quick Look methodology to apply play-specific models derived from the NULOOK Textural Vision petrophysical analysis and the NUSTIM® GeoTextural Logs and match these against successful completion scenarios from comparable analogue wells taken from our large archive of historic projects in proven shale play fields.

Reserves and EUR Analysis

The second build phase of the UK Regional Field Study also applies our NUSTIM Pro EUR Analysis to calculate Expected Ultimate Recovery for each of the wells. A Cumulative Probability for EUR with Recovery Factors derived from historical producing US oil shale plays will be used to provide a comparative analysis on recovery, and so deduce economic viability. Results from the EUR analysis for all wells in the shales will then be mapped to show the variability of the play and to highlight sweet spots or areas of higher producibility. This can be combined with the output from the NUVIEW® Field Study 2D Property Model to further enhance the understanding of variability of the shale play potential and aid the identification of the sweet spots.