Due to the complexity of the flow regimes encountered in highly deviated and horizontal wells it is not possible to use conventional tools to obtain the production profile.
More complex multiprobe or array tools are used with distributed measurements around the cross section of the pipe.
Emeraude includes specific treatment for the Schlumberger PFCS, GHOST and FSI, the GE Sondex MAPS suite (CAT, RAT, GAT and SAT), OpenField FAST, Baker Hughes PAI, Hunter-Probe (AFC, AFR, AFV and AGH) and Spartek probe tools.
Moreover, Emeraude allows the definition of any arbitrary multiprobe tool geometry and measurement type, in case the tool to be analysed is not included in the built-in library.
Templates for facilitating the QA/QC of measurements are available for all the tools.
Image views are created and cross sections displayed at any depth, and for any combination of passes.
A regression process fits the discrete measurements with the relevant 2D models, contingent on user-defined constraints on segregation, phase presence or other tools.
Average values of phase holdups, mixture velocity, and phase rates are produced and serve as inputs to the final interpretation.
Selective inflow performance (SIP)
In a multirate PLT, the well is logged at different surface rates. For each choke setting, the contribution of the zones and corresponding bottom hole pressures will change. Plotting the bottom hole flowing pressure versus the contributions for each zone, it is possible to obtain an IPR curve for each producing layer, and therefore quantify important reservoir parameters, such as reservoir pressure, productivity index and absolute open flow.
In Emeraude, an SIP analysis can be made with a few clicks. Pseudopressures can be 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 L.I.T. 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.
Increasingly, wells are completed with fibre optic distributed temperature sensors (DTS).
Even in a conventional PL job, the spinner may fail or give an erroneous response under certain circumstances (counter current, high viscosity etc).
If the thermal properties of the fluids, completion and formation are known it is possible to perform quantitative production or injection profiling.
Coupling energy and mass balance equations, Emeraude offers methods for production and injection profiling and annular leak detection.
Also, Emeraude incorporates specific formulations for Water Injection Fall-off (warmback) and steam injection.
A simplified Thermal/DTS workflow is available.
Visit the Thermal page to learn more about thermal solutions in Emeraude and Rubis.
Apparent permeability (APERM)
Estimation of effective permeability at reservoir scale is fundamental for an accurate reservoir model. In carbonates, the permeability in vuggy or fractured intervals can be dramatically different from the matrix permeability measured in core plugs. The apparent permeability based on PLT data may be the solution for a field-scale characterization.
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.
Once the well has been completed, it is not possible to use the typical open hole resistivity logs for the determination of formation water saturation.
Pulsed neutron logging techniques, based on the decay of the population of thermal neutrons, is the most common way to obtain the water saturation behind casing.
Since the capture cross section of the chlorine is much higher than the other elements found in the formation, the saturation of saline water may be determined.
Emeraude incorporates a specific workflow for analysing Pulsed Neutron logs in Sigma (capture) mode.
Models for clean, shaly and dual water formations are available.
A number of crossplot techniques facilitate the determination of the different component’s sigma values needed for determining the formation water saturation.
Once obtained it is possible to display the evolution with time.