Geomechanical software for multi-well injection optimisation of complex fields

Modern methods for defining injection rates to maintain correct reservoir pressure are based on Large-Scale Models of subsurface geology. Computational grids with 10 to 100 million cells are built from seismic data and rock properties available from bore samples. However, the accuracy of the models is highly dependent on the quality of the input parameters, and the models do not give well-specific information or knowledge about well interdependencies. They require labour intensive manual calculations and pose a serious computational challenge to numerical simulators. The high complexity of the models means that they require significant time and resources to be activated, and are therefore only used for injection planning of new IOR-campaigns and periodical updates of existing campaigns. Geomec proposes a completely new approach to obtain information about reservoir response to well-specific changes in injection parameters in real-time. Instead of focusing on a high spatial resolution of the reservoir that gives a single image in time of the reservoir, we reduce the spatial resolution in order to obtain a continuously updated image (movie) of the changing reservoir response. Geomec's solution offers conversion and analysis of continuously extracted data from existing well sensors, e.g. downhole pressure and volume flow rates in producing wells, and surface pressure and volume flow rates in injection wells. There is no need to install new sensors or hardware. In this project, we will in collaboration with our partners Premier Oil, Lundin and OMV demonstrate and customise the software for injection optimisation across multiple water injection wells and production wells. Three different operators with five different oil fields are chosen in order to gain new knowledge about functionality on different types of bedrock, and to gain experience from different operating procedures. Since the project started in June, we have conducted a full-scale test following a patent pending methodology on a single injection well in the Barents Sea in cooperation with OMV. We have shown that the entire process from planning, to concept implementation and after-work has worked as intended. The GeoTool-inject software has been synchronized with operators' software, correct protocols have been developed and critical bottlenecks have been identified. The test has been very successful and has shown that safe injection in the Barents Sea is possible. The experiences from this test on a single well will form the basis for the development and planning of future tests on multiple wells. In 2018 we analyzed the first two wells on the Edvard Grieg field. The analysis confirmed that the data available at the PDO stage were insufficient to predict their thermo-mechanical behaviour - i.e. an error factor of 2 to 3. Combined with the results obtained during the specially designed well injection test on OMV's Wisting appraisal well, the project has convincingly demonstrated that a novel approach was possible compared with the currently used Best Available Technology for design water injection in future fields. In turn, this new approach is now field-proven. In second half of 2018 Premier Oil's Solan field has been connected to GeoTool-Inject and analysed. A number of features have been added to GeoTool-Inject to increase the amount of information extractable from injection data. The feasibility of coding the multi-well interaction has been demonstrated. The coding of the model has started but it will take a significant amount of time. The use of pattern recognition is being investigated to improve the analysis of the shut-in periods when they are short or when the formation has poor petrophysics characteristics (low permeability). In 2019, connection was established for wells in Vår Energi's Goliat (new), Premier's Catcher in UK (new) and a new well in Lundin?s Edvard Grieg. Spirit Energy Norway joined the project with Oda. The fields studied in the project were at various levels of maturity from appraisal (Wisting), past DG3 (Fenja), pre-start-up (Oda) and past production start (Catcher, Edvard Grieg, Goliat and Solan). All possible well configuations were tested in terms of metering, wellhead accessibility, completion type, reservoir type, operatorship/partner, etc. The total number of wells analysed during the project - i.e. twenty two - offers a very serious database from which to draw experience, statistics and design of improved Best Available Technology (BAT). Three main innovations were sucessfully demonstrated. - A new type of well test for appraisal well was implemented and broke records on the NCS - A systematic start-up procedure for water injectors was tested on multiple wells, leading to greatly improved information gathering. - GeoTool-Inject can provide the results of a permanent virtual logging tool suite at a fraction of the cost of running physical logging tools.

Through real-time analysis and systematic extraction of information from big data, GeoTool-Inject can: - Reduce the probability of out-of-zone and reservoir leakages from more than 25% to less than 5%. - Ensure and optimise connectivity between injection wells and production wells and thus improve the ultimate recovery rate by 5 - 10% compared with current best practices. - Reduce the time to detect reservoir leakages from months/weeks to hours. - Reduce investments and operational costs and ensure manpower efficiency.