Saphir was first developed over twenty years ago by two engineers who needed a tool for their own interpretation work. It was fast, interactive and robust and it remains so but much has changed. Saphir has grown to a dominant position in the Industry with over 2400 commercial licenses used as standard by nearly all the Major IOC’s and NOC’s and other clients across operators, service companies and consultants on all continents.

The Saphir methodology has always been based on the Bourdet derivative as the main diagnostic tool; matching the measured data to the model taking into account the detailed production history.

The ever-increasing processing power of PCs has enabled KAPPA to aggressively expand the technical capability of Saphir. This has resulted in the development of extensive and fast numerical modeling, extension to nonlinear problems in Saphir NL, multiple deconvolution methods and now integration with other modules in the Ecrin suite.

In v4.12, as module interconnectivity develops, sectors of a full-field Rubis model can now be extracted and simulated in Saphir. Layer rates from PLT’s in Emeraude for multilayer analysis can be imported and, with the concurrent release of the Amethyste WPA module, wellbore models and IPR / AOF can be exchanged on a single click. A new numerical fractured horizontal well model is now available and Saphir NL can now model desorption for shale gas and coalbed methane. A new deconvolution method has also been added.

Generally the most tedious and time consuming part of PTA, is to input the known parameters, load rate and pressure data, quality check, edit where needed, then extract the period of interest, generally shut-ins, in order to start the interesting part; the loglog and specialized analyses. So, although this is not the most riveting of subjects, Saphir can load an unlimited number of gauges, rates, pressure and other data in almost any format including ASCII, ExcelTM, PAS and databases of all kinds via OLEDB & ODBC. Data may be input as points (time, value) or as steps (duration, value). Saphir has real time links with various acquisition systems, and data drag-and-drop from other Ecrin modules and Diamant Master. It is possible to start a build-up analysis from the direct selection of a shutin phase in Diamant Master. In the case of a multi-layer test, layer rates may be extracted to discriminate the layer contributions from the PL module Emeraude.

There is a comprehensive range of interactive edit and QA/QC tools including trends, tidal correction, gradient analysis, and the possibility to compare various gauges to detect gauge drift and wellbore effects between sensors.

Saphir can define a Vertical Lift Profile (VLP) or import a well intake model. In v4.12 and with the release of the Amethyste WPA module, it now possible to generate the VLP in Amethyste and drag-drop this into Saphir. The VLP is used in conjunction with the analytical or numerical model to simulate the pressure at gauge depth, in particular at surface. Alternatively the VLP can be used to correct pressure data a priori to reservoir depth.

All Saphir analytical and numerical models may be used to generate a virtual gauge on which a complete analysis may be simulated. Simulation options taking into account gauge resolution, accuracy and potential drift can be the basis for selecting the appropriate tools or to check if the test objectives can be achieved in practice.

Once data are ready the loglog and specialized plots can be extracted. Alternatively, the Saphir deconvolution option can be used to create an equivalent, extended drawdown response from several successive build-ups. There are caveats, and the assumptions behind these developments, limitations and suggested usage are developed in the free KAPPA Dynamic Flow Analysis book. Saphir was the first commercial product to make these techniques available to its users, and in this third release of the Deconvolution it is the only program to offer four different methods: (1) a single deconvolution to match multiple build-ups with a variable initial pressure (2) one deconvolution per build-up with a single fixed value of initial pressure (3) single deconvolution to match multiple build-ups with the ability to ignore the early time of all but one period to deal with inconsistent early times, and in v4.12 (4) a hybrid; method (3) followed by method (2) in the same automated loop.

Additional specialized analysis plots can be created with options tailored to specific flow regimes. These include very short term tests or FasTestTM for Perforation Inflow Testing and predefined types such as MDH, Horner, square root and tandem root. The user creates straight lines, by regression or interactively, and Saphir calculates the relevant parameters.

Saphir offers a comprehensive built-in analytical catalog allowing combinations of the traditional well, reservoir and boundary models. Additional specific external models are available and listed on the Technical references page. Interactive ‘pick options’ are offered for most parameters for a first estimate by selecting a characteristic feature of the model on the Bourdet derivative plot. If the user gets stuck there is the option to use the AI package ‘KIWI’ as a guide. Additional capabilities include rate dependent (non-Darcy) Skin, changing wellbore storage, interference from other wells, gas material balance correction for closed systems, well model changing in time (e.g. pre and post frac, or changing Skin), horizontal and vertical anisotropies and layered (commingled) formations.

Since v3.0, numerical models have been used to generate complex geometries with physical parameters beyond the scope of analytical models. This is predominantly 2D but with 3D refinement where needed. The mechanics for building such models are described on the Analysis of Dynamic Data page. In v4.12 the most complex numerical model to date has been added to solve the problem of fractured horizontal wells.

Saphir NL (NonLinear), uniquely in the industry, handles various types of nonlinearities: the slightly compressible fluid assumption and pseudopressures are replaced by the exact diffusion equations solving for real gas diffusion, non-Darcy flow, pressure related physical properties, multiphase flow, water injectors and water drives. In v4.12 gas desorption based on the Langmuir isotherm, for shale gas (single phase, combined with the fractured horizontal well) and coalbed methane (2-phase water-gas) have been added.

A sector of a Rubis full field 3D reservoir model can be imported and used in Saphir. In essence it enables Saphir to go beyond the current Saphir NL limitations and to use the Rubis sector analyses as a tool that can simulate complex three-phase flow processes with gravity. The key element of this new integration step between the Ecrin modules is that the model is not simplified upon its transfer from the full-scale simulator model in Rubis to the PTA module Saphir. The full-scale simulation model is simply stored in Saphir and re-simulated from there. This approach is possible because the full-scale Rubis model contains, by design, the ability to simulate, accurately and precisely, transient flow responses due to the well upscaling feature.

Saphir integrates a comprehensive multilayer analytical and numerical option with an unlimited number of commingled (analytical and numerical) or connected (numerical) layers. Each commingled layer has its own initial pressure. For the analytical models, for each layer the engineer may select any standard or external model. Individual stabilized and/or transient rates can be loaded and associated to any combination of contributing layers. Rates may be loaded directly from the Emeraude PL analysis module. The model simulates the pressure response and the combination of layer rates that were loaded with simultaneous optimization on both pressures and layer contributions.

After model generation, nonlinear regression is used to optimize the model parameters. This may be automatic or the user may control the list of variable parameters and their acceptable range, as well as the weight assigned to different data sections. Optimization may be performed on the loglog plot or on the whole production history. Confidence intervals may be displayed at the end of the regression process. Sensitivity analysis may be performed by running the same model for different ranges of parameters. Multiple analyses may be overlaid and compared on all plots.

Saphir performs AOF / IPR analyses, available for vertical, horizontal and fractured wells. The IPR can be used for flow after flow, isochronal, or modified isochronal tests. It includes options to display extended, stabilized, and transient IPR. Shape factors for IPR, and average pressure calculations are available for closed as well as constant pressure systems.

The result of the IPR study can be drag-dropped into Amethyste. Alternatively, Saphir can send the test data to, and retrieve the IPR study from, Amethyste.

This temporary Saphir addendum is provided for users who wish to have a simultaneous match of source and observation pressures. The v4.12 FT module permits the interpretation of any number of probes, active and interference, to discriminate vertical permeability. Models for packer-probe and probe-probe interference are included with the latter considering storage and Skin. An inbuilt preprocessor handles LAS format files and there is an option to calculate rates from pump volumes.

Saphir has an extensive range of comparison, reporting, exporting and printing capabilities. The free and unprotected Saphir Reader allows files to be read, printed and exported without the requirement for an active license. In v4.12 a new ‘slide presentation format’ has been added to use Saphir ‘live’ on a LCD projector or to copy/paste plots into PowerpointTM.