Well placed precisely within a target zone while avoiding offset wells in yellow. Cross sections through two different attributes in a geologic model are shown along with the 3D seismic in the background. Data courtesy of Rocky Mountain Oilfield Technology Center and USDOE.
In commercial oil and gas production, a shale reservoir is often preferred for its abundant recovery potential. But the recovery on this unconventional reservoir does not come without its own set of challenges. While many factors come into play during the drilling, completion, and production phase, one that highly influences the production is optimal well placement. For drilling and completion engineers, precise knowledge of well placement location in relation to the reservoir and adjacent wells assists in key decision-making regarding drilling risk reduction and maximizing economic potential.
Technologies such as 3D modeling and visualization have immensely simplified the way these well paths are monitored, allowing for precise planning and design for an effective transition to the next phase of the project.
Visualizing the Well Path in a Shale Reservoir
Comprehensive knowledge of reservoir characteristics is the initial step in designing an optimal well path. Given the complex lithology of shale reservoirs—which often contain micro-scale sub-facies of clay particles, carbonates, and silty sands among the mostly homogeneous shale—the analysis can be at risk of misinterpretation. Accurate 3D geological modeling minimizes this risk with the integration of lithological, geological, and petrophysical properties of the subsurface. These data obtained through well logging and seismic techniques provide information such as porosity, permeability, facies distribution, mineral composition, and location of faults and fractures. Representation of these subsurface data on the geological model allows well planners to make an optimized decision for well placement in a shale reservoir.
For new and existing oil fields, advanced well planning technology allows planners to successfully:
- Determine optimal target through the integration and analysis of well logs and seismic interpretation data if available.
- Understand the stratigraphy along the planned well path.
- Generate a traveling cylinder diagram to assess the proximity of the planned trajectory to the existing offset wells.
- Perform collision-risk analysis for single as well as multi-lateral well plans.
- Visualize a well path for optimal wellbore drilling and placement.
- Perform collision scans with real-time drilling assessment.
- Perform proximity monitoring along faults and fractures during drilling.
- Estimate positional uncertainties to understand the need for relief wells in case of collision between wells.
- Reduce potential drilling issues, like stuck pipe, by minimizing dogleg severity.
The ability to locate the optimal well placement zone for maximum recovery in the new oil field, as well as establish the well locations in mature fields, CoViz 4D enables teams to make informed decisions to improve the economic viability of the project.
Effective Visualization for Minimizing Risks
For well planners, designers, and engineers, advanced software like CoViz 4D and WellArchitect allow the integration and 3D visualization of subsurface data. This provides the ability to correlate and analyze the data to understand the challenges of various trajectory options. Precise 3D location of wells during drilling and completion provides asset teams with the ability to:
- Minimize the chances of wellbore collision with real-time visualization to make accurate steering decisions in case of close proximity with an offset well.
- Minimize the chance of drilling out-of-zone that could result in an expensive re-tracking process.
- Maximize recovery in new and mature oil fields by accurate well positioning in optimal pay zones.
- Reduce drilling risk, maximize recovery potential and ultimately increase the economic viability of a shale reservoir.
The real-time monitoring with visualization of a well’s location provides the ability to analyze the current plan, evaluate the options, and make changes in the spot if necessary. This facilitates optimal well placement in shale reservoirs.
WellArchitect and CoViz 4D for Visualizing Well Placement in Shale Reservoir
Dynamic Graphics Inc.’s WellArchitect works along with CoViz 4D to develop a high degree of visualized 3D precision in the location of wells. CoViz 4D integrates different geological models with well and reservoir subsurface data into a single geospatial volume. WellArchitect monitors the drilling progress in real-time in relation to the existing plan and provides an actual picture of the wellpath. The ability to visualize the path, analyze the risks, evaluate the options, and alert in case of potential risk allows drilling and completion engineers to reduce time and capital expended in the development of an asset.