Easily compare oil-gas-water ratios among several wells. Data used with permission of owner.
The water/oil ratio (WOR) is one of the more important metrics in calculating the economic value of a producing well. Reservoir engineers calculate water cut to update reserve and ultimate oil recovery estimates and refine the decline curve over the life of a well. With a WOR trending toward 100%, production engineers, reservoir engineers, and even financial analysts need to pool their skills and experience to analyze well performance and determine the well’s economic future. The barrel price of oil, utilities, maintenance, water remediation and disposal, land, and other expenses factor into the profitability equation.
No reservoir team wants to shut a well without exploring viable options to mitigate high water cut oil production. Reservoir teams gain a more detailed understanding of the factors that affect WOR by integrating and visualizing production data with data that characterize developing reservoir conditions. With this insight, engineers can more readily identify the factors or causes of increasing WOR and determine effective mitigation strategies.
Compare High Water Cut in Oil Production With Other Wells
The ability to create 2D plots of fluid production for a well to compare with nearby well production is a highly useful step in determining high water cut. However, that doesn’t give the full picture of water cut in a reservoir. Geologic data, completion information, petrophysical logs, as well as secondary or tertiary recovery techniques for similar wells provide additional guidance regarding reservoir characteristics that assist in the water cut comparisons. Furthermore, comparing fluid production amongst nearby wells in a 3D spatial context allows for possible identification of trends or patterns that aren’t noticeable looking at production curves.
Without the right tools, comparing a wide range of well data can be time-consuming. Comparisons are made far more efficiently when well data is integrated and evaluated visually in 2D graphs and 3D animations over time. Shared access to all relevant well data and a collaborative visualization environment enables well-by-well or section-by-section comparison, assessment of the complete well program, e.g., injectors and producers, or even evaluation of the entire oil field. With these capabilities, reservoir teams gain a far better understanding of fluid migration in the reservoir as well as have a great overview of where to begin any possible mitigation efforts.
Identify Factors Influencing High Water Cut in Oil Production
Visualization of reservoir conditions and monitoring production data also makes it easier to identify factors that are likely to influence high water cut. Production data reported on a spreadsheet is not as meaningful as production data visualized in context of the local geology and offset wells. Gradual or sudden changes in water cut are more easily diagnosed when production data is analyzed along with detailed, relevant data that document, drilling, completion, and historical production of all wells.
Easy access to this level of detail, allows reservoir engineers to more readily and confidently identify problems, such as those listed below:
Problem
Casing leak caused by sucker rod abrasion
Incomplete plug closure in depleted zone
Water zone not completely isolated from pay zone
Coning in vertical wells
Identified By
3D visualization of the wellbore shows a severe dogleg at the water zone level
Earth model shows where tracers added to the injection well are migrating to the production well
Latest seismic survey and review of 3D geologic model reveals additional faults and fractures
Visualizing oil-water contacts across all the wells in the field reveal uneven heights amongst the closest wells
That’s certainly not a complete list of the problems that lead to high water cut in oil production, but it does illustrate how access to relevant well and subsurface data—and the ability to visualize it—help isolate the source of water, identify the problem, and propose appropriate solutions.
CoViz 4D to Identify High Water Cut in Oil Production
Reservoir engineers contending with high water cut in oil production can benefit from the capabilities of CoViz 4D, a versatile data integration and visualization software developed for the petroleum industry. CoViz 4D easily integrates and visualizes a wide range of data types that reservoir and production engineers, geologists, and petrophysicists rely on. By combining these data to provide a detailed 3D visualization of subsurface environments, petroleum professionals gain a more detailed understanding of the interplay of reservoir characteristics and development decisions that affect well performance.
CoViz 4D is exceptional in enabling reservoir engineers to visualize changing reservoir conditions and their impact on production. The ability to analyze trends in WOR over time, in a single well or in comparison to nearby wells, and review the effectiveness of previous mitigation techniques, gives reservoir engineers greater confidence. With CoViz 4D, reservoir engineers gain insight into how to avoid potential water cut issues when planning future wells, monitor developing water cut metrics, identify problem sources, and devise appropriate mitigation strategies for high water cut in oil production.
CoViz 4D, a data visualization analytics software from Dynamic Graphics, Inc., gives oil and gas professionals the ability to easily access and combine all relevant data associated with petroleum assets. Powerful visualization capabilities enable you to explore data relationships, calculate and show inferred data, and analyze how data changes over time, allowing your team to confidently make decisions on the field that positively impact profit and reduce operational risk. To learn more about CoViz 4D contact our team.
