Emeraude is the industry standard software platform for production log interpretation, shared between all major service companies, most operating companies and many independent contractors worldwide.

Emeraude v2.60 offers a choice of zoned and continuous processing, with a two-step global regression that matches the log data at all points. The handling of multi-probe tools (MPT), such as Schlumberger FSI and Sondex MAPS, produces an open, streamlined workflow with an unparalleled range of tools for displaying, editing and handling data.

An ‘energy’ temperature model was also added to simulate reservoir thermal behavior to interpret steam injection tests and DTS data. Additional options include multi-rate PL and SIP, water saturation (PNL) monitoring, permeability correction and formation test QA/QC.

Emeraude is currently a stand-alone application that will migrate to the Ecrin environment under Generation 5. The Ecrin well performance analysis module Amethyste is now offered as an add-on for any license of Emeraude under active maintenance and under the current pricelist.

Recent years have seen a step change in the complexity of wells with multiple zones, phases and deviation ranging from vertical to horizontal. This has led to the development of esoteric logging tools with multiple arrays attempting to describe the complex and constantly varying flow regimes. Masses of data are created that needs visualization, QA/QC and analysis. It is not a straightforward process. It is easy to succumb to the temptation of a ‘black box’ that will do some clever statistical stuff and generate what looks like a perfectly acceptable analysis when presented in PowerPoint™. Looks pretty but it could lead to fantastically expensive errors when misguided well interventions are made. Production log interpretation is not rate measurement. The key to the process is in the name: Interpretation. Engineers interpret, machines do not. The engineer must control the software not the other way around.

Emeraude can load logs and stationary data from LIS, LAS, and ASCII files. Automatic tracks are built to give an instant view of the log data while customized views can be created. A well sketch can be built by completion component drag-and-drop. All display settings can be customized and templates created.

The hierarchical Emeraude documents contain an unlimited number of surveys and interpretations. The Emeraude browser contains a wide range of editing options: lateral average, depth stretch, shift, data cut and fill, merging, splicing, derivative, sampling, userformula module, additional functions through external DLL’s. Stations can be displayed vs. time.

Multiple spinners can be handled simultaneously, in particular for multi-probe tools. Various calibrations and editing may be performed on user defined spinner calibration zones. Apparent velocity channels are then calculated for each pass and each spinner.

Emeraude black-oil PVT offers a wide choice of correlations which can be viewed and matched to user-defined measurements. Tables may also be loaded. If the PVT is zoned, properties are redefined for each inflow zone. A steam-water model is available to analyze steam injection wells.

Rate calculation is treated as an optimization problem using nonlinear regression, with full flexibility in the type and number of input measurements, as long as they are in sufficient number: apparent velocity, density, pressure gradient, capacitance, phase holdup, phase velocity, phase rate, temperature, etc. Calculations may be zoned or continuous. The zoned calculation focuses on user defined intervals. The continuous method seeks agreement everywhere on the logs, and the holdups are treated as variables, allowing a possible deviation from the slip model. The zoned method works well most of the time and it is very fast. The continuous method may provide a better answer in complex cases and when attempting to match the temperature. The user has the choice.

The local regression in the zoned method calculates cumulative rates on selected intervals. This may also be the starting point for the continuous method, where a global regression solves for the contributions of the inflow intervals. Such a global regression solves for the entire well at once using user-defined constraints such as the contribution sense, surface rates, etc. It is also possible to fix any particular contribution to a fixed or null value.

Emeraude offers a complete range of flow models from single to 3-phase. Specific models are provided to handle flow re-circulation and standing water columns. Three and two-phase liquid-liquid stratified models for horizontal and highly deviated wells are available. It is possible to connect user models through an external DLL interface.

Emeraude includes a specific treatment for the Schlumberger PFCS, GHOST, and FSI, and the Sondex MAPS suite: the CAT, SAT and RAT tools. Image views are created and cross sections displayed at any depth and for any combination of passes. A process fits the discrete measurements with relevant 2D models, contingent to user-defined constraints on segregation, phase presence or other tools. The output can be presented for QA/QC, and results compared with the raw data. Average values of phase holdups, mixture velocity, and phase rates are produced and serve as input to the interpretation.

Clean formation and shaly single / dual water models are available. Channels may be estimated from correlations or loaded from other openhole interpretations. Classical crossplots can be created to obtain or correct estimates. Time-lapse presentation can be generated.

SIP can be made with a few clicks. Pseudopressures are used for gas. An unlimited number of SIP’s can be created and compared. Each zone can be assigned a different model: straight line, c&n, or Jones. The SIP can use the total rate, a phase rate, or the total liquid rate. Data may be downhole or from surface. Pressure datum correction and composite IPR’s are available.

Emeraude offers a segmented model and an energy model. The analytical segmented model accounts for enthalpy balance in front of inflow zones, and conduction / convection in-between. Joule-Thomson effects are calculated from a user estimated pressure drop. The numerical energy model solves the full energy equation in the wellbore and the reservoir, accounting explicitly for the thermal effects within the reservoir. Both models can be used for the analysis of DTS data, standalone temperature logs, or to replace a faulty or blinded spinner.

Tool responses can be modeled for any particular flow scenario. The simulated channels take into account the tool specific response, its resolution and the noise. Packer leaks and steam injection can be simulated.

Reservoir pressure, permeability and mobility may be loaded. Quality indicators can be added at any depth. Lines can be calculated or drawn, gradients and fluid contacts can be calculated.

This method corrects, with the PL interpretation, the open-hole effective permeability. It uses an IPR relationship where the relevant reservoir or perforation parameters are defined zone by zone. The method is implemented for single-phase liquid, liquid mixture, or for gas using pseudopressures.

This special analysis uses a dedicated 2-phase steamwater PVT for the design of steam-injection tests. The temperature, pressure, holdup, and velocity profiles are calculated from surface, to come up with the property of the injected fluid in each zone. Relevant slip models are considered.

Emeraude log channels can be exported in LIS, LAS, or ASCII format. Log tracks and X-Y plots can be copied to the clipboard as a bitmap or a Windows Metafile. Fonts, scales and grid lines can be modified. API logs can be produced. A built-in report can be printed and previewed that includes predefined sections. It is possible to produce a report in MS-Word™ using the OLE™ interface of Emeraude. A template MS-Word™ report is installed and can be customized as required. All reporting and exporting features are accessible with the free Emeraude reader.