Subsurface Data Analysis and Visualization: Exploring Spatial and Temporal Diversity

Hydrocarbon reservoirs are by their very existence dynamic entities. As extraction commences the pressures and fluid relationship begin to change. Subsurface pressures gradually decrease over time as production occurs. Enhanced extraction techniques boost pressures by injecting fluids to arrest the declining pressures. We can see that the reservoir is in a state of flux as pressure changes cause the fluid contacts in the reservoir to shift continuously as injected fluids pushes the lighter oil towards infill wells locations. The reservoir simulation model is one attempt to capture the dynamic nature of the reservoir. It models the change of saturations and pressures over time, but it is a model and as such can deviate away from reality. In order to validate the assumptions made in our models we have to incorporate additional data, 4D seismic, production data, DAS/DTS, SAR, etc. In order to validate the model’s changes over time, the additional data must also be available in a temporal sense. CoViz 4D offers the ability to display multi-discipline data in various forms in a temporal environment. Data can be observed both in a spatial and temporal sense to elicit a greater understanding of the mechanics of the reservoir through subsurface data analysis.

Fields that elicit a strong 4D signal from the reserve are best served by investing in repeat seismic surveys. The additional cost is insignificant compared with the ability to look into the reservoir and take a snapshot of the internal fluid distributions. Comparison of the actual (4D seismic) and the simulation allows the simulation model to be corrected, providing a more accurate representation of the reservoir conditions. Such a visual comparison would be impossible without the ability to equally represent the seismic snapshot and the reservoir simulation at the same point in time. CoViz 4D offers the user the ability to assign date and times to events such as 4D Seismic volumes so that visual comparisons in a multidisciplinary environment can be obtained.

Production data is the remit of the production engineer, volumes of oil, water, gas produced or injected are consigned to spreadsheets and reports. This invaluable data type is often neglected in the 3D spatial sense when assessing the state of the reservoir. The simulation is history matched to the simulation as a means to determine the configuration of rock properties that represent reality. To incorporate this time varying data into a multi-dataverse application like CoViz 4D allows a greater spatial awareness of rising/failing production based on well location. The ease of mapping the progression of the waterflood by mapping the increasing amount of formation water appearing in the production volumes and its comparison to the simulated water saturations allow for better understanding of the reservoir when having to make decisions regarding the overall operation of the field.

Distributed acoustic sensing (DAS) and distributed temperature sensing (DTS) are increasingly being used to assess the integrity of the wells following the Macondo oil spill. This datatype is continuously sampled over time and therefore requires a temporal environment to be analyzed. Viewed on it’s own it has limited benefits but in the company of ancillary data like for example well status ( periods when the well is producing, injecting, shut in, cementing, reworking, fracking, slugging, etc), the additional data adds context to the events seen in the DAS/DTS data stream. Only by the integration of multidisciplinary data can we build a more robust picture of the subsurface.

Surface deformations are an indication of the ever changing volumes of fluids present in the reservoirs. SAR (Synthetic Aperture Radar) measures very accurately the ground distortions. Regular overflights provide information that is only valid at the time of measurement. Using the date and time of the event allows the event to be aligned with other criteria, like 4D Geomechanics models that use the reservoir properties to displacements. Correcting the cell model to agree with the measured surface deformations provides a more accurate subsurface representation. One that will allow better, more informed decisions regarding the management of the asset.

Displaying various data in a multi-dataverse application like CoViz 4D has its own challenges – each set of data has to be displayed so the information contained can be relayed to the user in the most efficient display. The data will initially reside in various external applications. As a consequence the data will have to be read and understood and translated into a form ready for user interaction within the integrated environment. Temporal data is a measurement at a set time. That time element has to be tagged to the data.

Given all these challengers, the end product is an integrated environment that enables spatial analysis to be enhanced with temporal events.  Relationships between very different data types will be able to be viewed and understood using integrated analytical tools. CoViz 4D is unique in offering such a solution.

Integrated data visualization can foster a cohesive team environment by accommodating multidisciplinary data into a single package, enhancing workflows while buffering a creative environment that solves challenges. Workplace efficiency leads to sound management decisions that streamline campaigns and maximize hydrocarbon extraction.

CoViz 4D enhances subsurface data analysis by allowing users to focus key pieces of information that can lead to better management decisions. With CoViz 4D you can explore from small-scale to large-scale features seamlessly. CoViz 4D enhances subsurface data analysis by allowing users to link temporal events together. In this way ‘cause and effect’ studies enable a more complete understanding of the complexities of the sub-surface environment.