Well trajectory design is noticeably more efficient when well planners incorporate all relevant subsurface data into their planning process. Integrating data such as geologic and petrophysical models, survey logs, shallow hazards, surface equipment, reservoir grids, and existing wells into a common visualization environment gives well planners the best possible understanding of the subsurface environment and all its complexities. The ability to visualize and evaluate factors that influence well trajectories helps well planners minimize drilling risks and costs, and facilitates maximizing the recovery of oil and gas resources.
Integrated Data Provides a Detailed Understanding of Subsurface Conditions
The wealth of data generated and analyzed by the various disciplines involved in reservoir development and management—geologists, geophysicists, geochemists, and reservoir, completion, production, and drilling engineers—provides insight into specific aspects of reservoir conditions. When these data are combined to create a more integrated understanding of subsurface conditions, well planners can explore data relationships that help determine:
- How stratigraphy will impact drilling strategy and BHA components along the wellbore
- Completion methods—casings, cementing, stimulation, and stages based on seismic and petrophysical data
- Property distributions, such as porosity in a lithology layer originating in a sedimentary environment
- Hazards from nearby wells or hardline and easement constraints
Well trajectory design conducted with access to relevant data supplied by the multiple disciplines responsible for reservoir development increases confidence in making decisions that result in safer and drillable well plans.
Integration and Visualization Maximize the Value of Reservoir Data
Integrated reservoir data achieves its greatest value when visualized in a 3D environment to depict geologic formations, reservoir properties, and existing infrastructure. The ability to explore a reservoir in 3D, from any perspective, allows well planners to assess potential plans with the context of the overall geologic structure as well as focus on a specific area to assess properties that influence subsurface well trajectory design. At the macro and micro levels, data integration and visualization enables drilling engineers to:
- Plan the well trajectory from pad to target by interactively selecting intermediate and target locations in the 3D model and allowing well-planning software to determine (solve) the curve to connect the points.
- Selectively intersect or associate targets when designing the well trajectory.
- Visualize traveling cylinder diagrams in context of existing wells to aid in assessing collision risk.
- Identify fault or horizon intersection angles that could present potential drilling hazards.
- View a cross-section of a stratigraphic or property model to determine drilling requirements and aid in geosteering while drilling.
- Include annotation along the planned trajectory to provide detailed guidance or explanation of conditions.
- Develop and save multiple trajectory designs to evaluate the pros and cons of each plan with respect to drilling cost and long-term wellbore safety.
Integration and visualization of reservoir data also facilitate quick comparison of a proposed well trajectory with existing wells with similar geologic characteristics. Were any problems encountered during drilling? Were sidetracks required to circumvent problems? How accurately did the trajectory reach the target? What completion techniques were employed? What stimulations, if any, were made to optimize recovery? Lessons learned from comparable wells can guide well planners in developing safer and drillable well trajectory designs.
Unique Tools for Well Trajectory Design
Integration and visualization of relevant data allow well planners to develop well trajectory designs for optimizing wellbore placement within a reservoir. Software to easily integrate a wide variety and various formats of reservoir data, visualize them in 3D, and use those data to design well trajectories is available from Dynamic Graphics, Inc. (DGI). DGI, the leader in software solutions designed to solve complex spatial analysis problems for the petroleum industry, offers two software solutions for well trajectory design: WellArchitect, for those who need a full-featured directional well planning and drilling package, and Integrated Well Designer (an option within CoViz 4D), for members of the asset team who want to build their own trajectory design.
WellArchitect is an advanced software for integrated planning and drilling of directional wellpaths, including sidetracks, multi-laterals, and re-entries. WellArchitect can be used in the office as well as at the rig site for increased flexibility to handle everything from planning and survey calculations through data management and collision-risk analysis. The software includes traditional directional wellpath planning tools such as plotting, 3D visualization, anti-collision scanning (to evaluate the risk of collision between the planned path and other nearby wells), and target sizing to evaluate the size of the “driller’s target” (i.e., the geologic target “eroded” by the positional uncertainty of the path). WellArchitect goes beyond traditional tools by incorporating geologic and reservoir models, as well as 2D surfaces into the display while planning and drilling, including evaluating hazard-potential related to identifying intersection angles between the plan and faults or horizons.
WellArchitect goes beyond traditional tools by incorporating geologic and reservoir models, as well as 2D surfaces into the display while planning and drilling, including evaluating hazard-potential related to identifying intersection angles between the plan and faults or horizons.
Integrated Well Designer is available as an optional module in two other software products from DGI. One of the products, CoViz 4D, provides a vendor-neutral quantitative visual environment for reservoir management and seismic analysis. It enables reservoir teams to understand the changing reservoir response over time and optimize development and production decisions. Another product, EarthVision, provides the ability to create accurate and reliable 3D geologic models to facilitate improved reservoir characterization and environmental analysis, and enable more precise well positioning.
Integrated Well Designer allows non-expert well planners to interactively design wellpaths in 3D space using geologic, geophysical, and reservoir data. Geologic models can be queried at fault or horizon intersections to evaluate potential wellbore hazards. Well trajectories are created from simple building blocks using a spreadsheet-like application. Ellipsoids of uncertainty are displayed along with the wellpath. Traveling cylinder diagrams that interact with the 3D display indicate the relative location of offset wellpaths near or intersecting a planned path.
Integrate, Visualize, and Evaluate
Software tools that simplify the task of integrating different types of reservoir data, and provide a collaborative visualization environment as well as comprehensive planning tools, enable well planners to develop, evaluate, and recommend safer and drillable trajectory designs in context of subsurface conditions.