Abstracts on pages 2 to 5 Pdf of subjects 2 to 7 can be downloaded from the website

Transcription

1 Société pour l Avancement de l Interprétation des Diagraphies Section française de la SPWLA Society of Petrophysicists and Well Log Analysts The last Technical session of the French S.A.I.D. Chapter with subject : Core, Log and Rock Types «Mesures sur Carottes, Diagraphies et Rock Types» took place on Tuesday, November 29, 2016 from 14:30 to 18:30 in the room Ver Straelen of SGF, 77 Rue Claude Bernard, Maison de la Géologie, PARIS Abstracts on pages 2 to 5 Pdf of subjects 2 to 7 can be downloaded from the website 14:30 - Introduction-HSE par Jacques Delalex, Président de la S.A.I.D 1-14:35 15:00 : Rock-typing as a key tool for the characterization and modeling of conventional and non-conventional reservoirs Raphaël Lalou, RGEPI 2-15:00 15:30 Comparison between Porosities measured in laboratory and Porosities derived from logs Roland Lenormand, CYDAREX, Past-President of SCA, Society of Core Analysts 3-15:30 16:00 Use of NMR for Rock Typing: link with pore size distribution Marc Fleury, IFP-Energies Nouvelles 4-16:00 16:30 An implementation of Purcell method for MICP integration, pore typing and saturation height modeling Philippe Rabiller, Geo Consulting 16:30 17:00 Coffee break 5-17:00 17:30 Log petrophysical inversion at well scale Emmanuel Caroli, TOTAL 6-17:30 18:00 From Cores to 3D model: preparation of a static model using SCAL data Olivier Marché, Schlumberger SIS - MpTC 7-18:00 18:30 Supporting Sedimentological Descriptions in Unconventional : Core Log Analysis JP Leduc et P.Martinet, TOTAL 18:30 Clôture de la session

2 ABSTRACTS : 1- Rock-typing as a key tool for conventional and non-conventional reservoirs characterization and modeling Raphaël Lalou RGEPI The reservoir model is used to simulate the hydrocarbon production profile of a producing field and hence, to predict cash flow evolution. This model is based on a rock-type model, one of the most important elements in a typical reservoir study workflow. This presentation proposes a simplified workflow on Reservoir Characterization and Modeling studies. Specific emphasis will be given to the rock-typing step and the ways to determine Litho, Electro and Petrofacies. The main differences in the workflow between non-conventional and conventional reservoir will be also highlighted. 2 - Comparison between Porosities measured in laboratory and Porosities derived from logs Roland Lenormand, CYDAREX, Past-President of SCA, Society of Core Analysts The comparison between log and core porosities is still a very active debate on many forums on internet. In this short presentation, I will recall the main methods used in laboratory to measure porosity and explain why different methods lead to different results. Especially, I will explain the role of Kelvin condensation for the determination of clay porosity. 3 Use of NMR for Rock Typing: link with pore size distribution Marc Fleury, IFP Energies Nouvelles Relaxation time distributions obtained from Nuclear Magnetic Resonance (NMR) techniques are in principle very well suited for building rock types based on logging information. Under certain measurement conditions, it is sensitive to pore size distribution and can be calibrated in terms of permeability; hence this information is a key for a classification of formations in terms of pore structure or flow units. We will first recall the basic principles underlying the interpretation of relaxation times as a pore size distribution, as well as a permeability indicator. Then we give some examples in shaly sandstone and carbonate formations of NMR laboratory and log data useful for rock typing, as well as some limitations of this technique in specific cases. Finally rock typing in shales is also discussed.

3 4 - An implementation of Purcell method for MICP integration, pore typing and saturation height modeling Philippe Rabiller Geo Consulting As Pore Type controls storage and fluid flow in the downhole pressure and fluid context of production history, characterizing the rocks by their pore type is important for reservoir characterization and modeling. It is also important in the search of stratigraphic traps and to evaluate the sealing efficiency of the capping rocks of any trap ahead of its exploration. The presentation describes a method meant at processing MICP measurements which so far are the most used means to perform pore typing and derive saturation-height curves. The method relies on a regular re-sampling of the Saturation as a function of the Pressure and eliminates the need for manual sorting or use of curve fitting methods such as Thomeer s hyperbola or Gaussian fitting functions. Conformance correction and picking of the Katz & Thompson Threshold and Entry Pressures are automatic and editable. MICP drainage and imbibition curves measured using varied pressure steps are processed, without any user bias, so as to deliver a log which is displayed with other logs in layouts and X-plots views and most importantly is suitable for the application of clustering (definition of Pore Type) and data prediction techniques. The classic permeability modeling methods are embedded in the process. Because PSD is a scalar variable, up-scaling it by means of multiple k-nn prediction and histogram up-scaling method is made straightforward. As a result of MICP integration with other logs, upscaling and prediction of PSD, computing the saturation at any depth increment, for any given height above Free Water Level, is made straightforward. To date, the method proposed here has been successfully field tested well over 3000 MICP curves measured in various complex reservoirs. Its application led to design a way to define a dynamic cut off for the permeability and to derive a simple MICP-Proxy from plug poro-perm measurements. 5 - Log petrophysical inversion at well scale Emmanuel Caroli, TOTAL In a conventional formation evaluation process, the mud filtrate invasion in the near wellbore is considered as a bias which is corrected from logs before any petrophysical evaluation. The developments presented in this paper show that the invasion zone is a valuable source of information to estimate dynamical properties that generally come only from core measurements such as permeability, relative permeabilities, capillary pressure curves and formation factor. In this approach, the invasion process is not explicitly simulated versus time as it would lead to an illposed inverse problem within the time frame of the logging (LWD is generally logged too early and wireline too late to efficiently constrain the dynamics of invasion). But, if the fluids in the invaded zone are close to equilibrium, hence governed at first order by capillary pressures, their radial distribution can be solved and dynamical properties efficiently inverted. However, due to the multimodality of the inverse problem and the uncertainties related to the mud-filtrate parameters, the invasion zone needs to be jointly inverted at field scale for each facies with the vertical capillary equilibrium condition. In the context of this paper, we present vertical wells and consider radial oil base mud invasion. We also assume isotropic petrophysical parameters. The final results are compared to cores for permeabilities, formation factor and capillary pressure curves. The ultimate added value of such an approach is to bridge static and dynamic petrophysical parameters from a single source of data: logs. It provides a reliable first guess of petrophysical and reservoir parameters at an early stage of the well evaluation. It also ensures an overall consistency of the formation model for the whole range of facies and fluid configurations. The technique can even help in the formation heterogeneity characterization and petrophysical upscaling when run in a multiwell configuration. The method can be generalized to any mud systems. In the case of water base mud, it could potentially resolve the relationship between drainage and imbibition which would be of significant interest for field simulation and production forecast.

4 6 - From Cores to 3D model: preparation of a static model using SCAL data Olivier Marché, Schlumberger Capillary pressures experiments and in some extend relative permeability are used in helping determining rock types. Static model preparation is often done by geomodeler using high quality data coming from Petrophysicists. Other times it is done by reservoir engineer, using similar data but without the same focus and grid resolution. How can these 2 similar workflows be reconciled using high quality data for new generation simulator? We will see the 2 approaches for initialization of the static model. The first approach will focus on the petrophysical approach with Saturation Height Modeling which provide users with a saturation function per rock type. The second approach will focus on reservoir engineer approach which starts from the same data, to deliver tables per rock type for the static model. Workflow 1: Workflow 2:

5 7 - Supporting Sedimentological Descriptions in Unconventional: Core Log Analysis JP Leduc et P.Martinet, TOTAL Unconventional reservoirs are also a challenge for sedimentologists: formations previously categorized into undifferentiated Black Shales have today to be split into various sedimentary facies while anticipating their properties (mineralogy, petrophysics, geomechanics) beside the classic geological or paleogeographic considerations, aiming at further 3D prediction of potential sweet spots or well placement. In overall extremely fine grained (micrometer size) sediments, few indices help the sedimentologist: visible fossils, lamination or bedding patterns or local lithological contrasts such as carbonate rich levels. Elsewhere, the rock is made of apparently homogeneous dark matrix, and mineralogy is often misleading in reason of subtle diagenetic processes. For this reasons, specific process was engaged by a multidisciplinary team (sedimentologist, log analyst, geomechanicist) for calibrating the sedimentologist s eye in the perspective of further optimization of the described facies. Continuous core acquisitions (CTscan, XRF elemental profiling) and sample analyses (mineralogical, petrophysical and geomechanical measurements) are combined into a high resolution Core Petrophysical Log. Clustering techniques are applied with objective to simplify information in the frame of facies definition. Combining the sedimentary facies and other core data originated in limited sections together with well log acquisitions, core data is then predicted along the complete reservoir interval while perfectly preserving the consistency between sedimentological interpretation and rock properties.