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Theme 2: Reservoir characterisation to improve volumetric sweep

Theme 2 works with the integration of field data such as pressure, temperature, seismic data, tracer data, geophysical data, and geological data into a field scale simulation model.

Publisert: Endret:

In Theme 2 we focus our research towards integrating all types of information/data available to improve and enhance decision-making in petroleum production. A main driver when conducting our research is to deliver new results and new methodology that will be applied by the industry.

Primary objective of Theme 2

The aim is to develop new and improved methodology that will support the evaluation and decision making with regards to IOR/EOR pilots at the Norwegian Continental Shelf (NCS). This addresses the potential of producing the resources in un-swept areas as well as mobilizing the trapped resources in swept areas. The research is focusing on challenges for the entire NCS while demonstrating the improved methodology on real field cases.

Secondary objectives of Theme 2

  • Further development of tracer technology
  • Improvement of reservoir simulation tools with regards to IOR/EOR processes
  • Robust production optimization
  • Better history matching through improved data assimilation tools
  • Inclusion of 4D seismic data in ensemble based history matching
  • Evaluation of economic potential
  • Investigation of the connection between the reservoir complexity and recovery factor potential 

These are the tasks in Theme 2

Task 5: Tracer Technology

Task leader: Tor Bjørnstad, Special Advisor, IFE (tor.bjornstad@ife.no)

The main objective of this task is to devise methods and procedures to map volumetric distribution of residual oil saturation in a reservoir after secondary production.  Such knowledge is the basis for evaluating the need for infill wells and enhanced recovery methods (EOR). Our approaches are based on improvement on existing and develop new tracer technology for interwell and near-well applications. The methods are based on the simultaneous use of passive water tracers and phase-partitioning (oil/water) tracer compounds. A secondary objective is to develop technology for improved description of high-permeability flow fields (fractures) between wells. This is based on the simultaneous application of molecular passive water tracers that will probe all available waterflow-contactable porosity in the formation and on nanoparticle tracers that will move preferentially in the fracture volumes.

The need for infill wells, EOR operations and conformance control are the most important targeted information. Main deliverables are “methodologies for evaluation of IOR potential” and “recommended practices” for these technologies.

Task 5 have, over time, consisted of two main subject parts: 1. interwell tracing divided between development of SOR measurement technology for flooded volumes and improved fracture/fissure description by application of nanoparticles and 2. near-well SOR determination divided between the development of new on-line analysable fluorescent molecular esters and their hydrolysis products for push-and-pull operation, and the development of an innovative concept of using nanoparticles as carriers (nanocarriers) for simultaneous transport of passive and partitioning tracers some distance into the reservoir before simultaneous release and back-production.

The laboratory-based experimental work on phase-partitioning tracers for SOR determination in flooded volumes between wells (sub-project 2.5.6.) has been finalized with good results. This technology is now ready for reservoir piloting. A dr-dissertation has recently been completed and accepted (Mario Silva). All results are given and discussed in detail in the corresponding comprehensive Thesis.

Previously,  continued work on particle tracers (carbon quantum dots or C-dots) for fracture detection  was merged with the program for development of nanoparticle carriers (sub-project 2.5.4) for the dr-student Arun Kumar Panneer Selvam (started in March 2019). Recently, one has decided to stop further experimental work on C-dots due to too severe inconsistencies in results between our own laboratories and foreign laboratories (mainly from Cornell and Saudi Aramco) which cannot be resolved within the remaining budget of the program. A state-of-the-art report will be produced during the fall of 2021. The remaining time for the dr.-student should be concentrated on nanocarrier development. This program, which has a considerable potential if completed successfully, has been allocated extra economic and manpower resources, and will be the main focus for the rest of 2021.

The sub-program for experimental development of lanthanide-based fluorescent hydrolyzing esters for near-well SOR measurement (sub-project 2.5.5.) was experimentally finalized in 2020. Topics like molecular synthesis and lanthanide complexation, instrumental analysis by UPLC/MS/MS, measurement of hydrolysis rate and flooding properties in porous media have been successfully completed. However, the required water/oil partitioning appeared to be non-satisfactory. Thus, the ultimate goal was not reached within the frames of this project. A technical report summarizing the most important experiments, results and recommendation for further work is now under production and will be published during the fall of 2021.

Task 6: Reservoir Simulation Tools

Task leader: Ove Sævareid, Senior Scientist, NORCE (ovsa@norceresearch.no

Improved modeling methodology and simulation capabilities for IOR are important to perform reliable pilot and full field simulations. In this project, we contribute towards the OPM (www.opm-project.com) simulation framework. This is an open-source code able of handling industrial relevant models, which provides a platform for testing innovative reservoir simulation developments in general. The project addresses improved simulation tools, which are important for simulation of any IOR processes. In particular, the complex physical and chemical IOR processes are in crucial need of improved simulation tools that allow for resolution of fronts and mixing zones. We anticipate that the resulting improvements will lead to better decision making and, hence, improve oil recovery on the Norwegian Continental Shelf. In collaboration with the Tasks in the Centre, and its focus on different scales, it is important to provide a simulator that is capable to simulate the physical processes in the reservoir with satisfying fidelity to generate the measured data. 

During first half of 2021 three Postdoc have been affiliated with Task 6.  PostDoc Runar Berge is working to enable discrete fractures in the field scale simulator OPM Flow for simulating flow in fractured reservoirs. PostDoc Birane Kane is working on implementation of a state-of-the-art solver for in-compressible Navier-Stokes equations modeling non-Newtonian fluid flow. In a joint effort between Task 1 and Task 6 in the center, PostDoc Oddjørn Nødland (UiS) is working to incorporate improved polymer flow models in OPM. 

Task 7: Field scale evaluation and history matching  

Task leader: Geir Nævdal, Chief Scientist, NORCE (gena@norceresearch.no)  

The economic feasibility of implementing new IOR methods on a field needs to be evaluated, preferably taking the uncertainty in the reservoir description into account. While optimizing future production, environmental constraints need to be considered. The evaluation will be based on history matched reservoir models. An important focus in this task is to develop better methods for full field history matching using 4-D seismic data. The history matching is done using ensemble-based methods, but we consider use of different types of seismic data for inversion. Some focus is on compacting reservoirs. Here we both study how to improve the interpretation of 4D seismic data for the location of water and pressure fronts and investigate the coupling between fluid flow and geomechanics linking 4D seismic observations to stress exchange in the reservoir and surrounding rock. A substantial part of the work involving 4D seismic is using real data, an open data set for the Norne field and data from Ekofisk that has been made available for selected studies within the IOR Centre.  

The paper “On the Robust Value Quantification of Polymer EOR Injection Strategies for Better Decision Making” by M. Oguntola and R. J. Lorentzen will be presented at the ECMOR conference held online in September 2020. This paper shows the integration of several tools developed at the IOR center. The authors find the optimal well controls for polymer flooding using ensemble-based optimization. The polymer flooding results are compared with conventional optimized continuous water flooding for three different synthetic fields. The reservoir fluid flow is simulated using the Open Porous Media (OPM) simulator. However, it is worth noting that the optimization method is independent of the reservoir simulator used. Important findings of this study are the feasible control strategies for polymer EOR methods leading to an increased NPV, and comparison of the economic values for optimized polymer and traditional water flooding for the examples considered. Some of the simulation results obtained during the study is also planned for use in the evaluation of the environmental effects of polymer flooding. 

One new PhD student arrived in the spring of 2020, Hoang Nguyen. His PhD project has the working title “Integrated geological, geophysical, reservoir, and decision analysis of the Edvard Grieg Field, Utsira High, North Sea”. After his arrival there are six PhD students working on Task 7. The other ones are Karen Ohm, working on elastic full waveform inversion, André Luís Morosov, who is working on the value of data and data analytics for IOR operations, Micheal Babatunde Oguntola, working on robust reservoir optimization and model evaluation for IOR decision making, William Chalub Cruz, working on data assimilation using 4D seismic and tracer data, and Nisar Ahmed who is working on frequency-dependent AVO inversion.