With a detailed understanding of the completion and production zones, completion engineers can collaborate with geologists, geophysicists, and drilling engineers to develop the initial perforation plan specifying plug offset, cluster spacing, stages, stage spacing, clusters per stage, and perforations per cluster.
A bad completion can ruin a well and waste millions of development dollars. Petroleum engineers who know how to exploit the inherent value of subsurface geologic and wellbore data are better prepared to design, drill, and complete wells to safely deliver maximum oil recovery.
Every stage of the development process yields additional data that can inform the management team of the evolving subsurface conditions. In the oil well completion phase, these data realize their greatest value when they can be visualized and analyzed in an environment that facilitates well-informed, collaborative decision-making for completion planning.
Wellbore Data: A Wealth of Detail to Guide Completion Strategy
In addition to seismic surveys that characterize hydrocarbon resources, wellbore data such as logs, gamma ray, and core analyses give engineers a detailed understanding of geology in the completion zone. Combining relevant wellbore data with subsurface data and visualizing it in 3D enables engineers to design the overall completion process by:
- determining how accurately the wellbore has reached and penetrated its target
- locating the production zone in relation to the overall reservoir structure to calculate the ideal number of perforation stages
- understanding the formation rock, its lithology, permeability, and porosity to determine if stimulation treatments are needed
- using data from nearby wells to see how those completions have historically affected oil production
- planning the types, number, and quantities of required production resources such as tubing, fluids, sand, chemicals, pumps, and safety valves
Having conducted this initial analysis, completion engineers can then explore and analyze the unique geologic factors at a more granular level. The ability to visualize the interplay of variables associated with the completion zone allows engineers to fine-tune the plan to ensure selection and placement of components that maximize both production and safety.
Evaluating and Planning the Completion Zone
The ability to isolate downhole zones, review well logs in context of surrounding geology and nearby wells, and visualize the pros and cons of alternative completion strategies enables completion engineers to make well-informed decisions regarding oil well completions. With a detailed understanding of the completion and production zones—facilitated by the ability to combine, visualize, and analyze the various datasets—completion engineers can collaborate with geologists, geophysicists, and drilling engineers to:
- Specify the appropriate casing or liner characteristics.
- Use well logs to select casing shoe location, specify any extra supports required to ensure casing reliability and safety, and ensure proper placement and cementing in place.
- Determine the maximum completable length, accounting for factors like hardlines, buffers, production top, and dogleg severity.
- Develop the initial perforation plan specifying plug offset, cluster spacing, stages, stage spacing, clusters per stage, and perforations per cluster.
- Fine-tune the perforation design using wireline data, including lithology, gamma ray, and gas content.
- Schedule the stage-by-stage perforation and fracking sequence.
- Recommend any required stimulations for low permeability—acidizing, fracturing, nitrogen circulation; specify appropriate proppants.
- Proactively plan mitigations for potential restrictions such as formation damage, clays, and solids that impede fluid flows.
A visualization and analytic environment leverages the experience and insight of all members of the reservoir management team to evaluate relevant data in 3D and filter, correlate, and explore data variables with the goal of developing completion plans that maximize recovery.
Leverage Historical Insight From Nearby Wells
A completion plan can benefit greatly from information on how a reservoir changes over time. By incorporating historical data sets—both geologic and operational—that depict reservoir evolution performance, and visualizing the changes across time (the 4th dimension), engineers can gain a sense of how existing wells in the area have performed. By comparing the completion plans and performance of similar wells, engineers can apply methods that have enhanced production and avoid methods shown to impede production.
A completion plan can benefit greatly from information on how a reservoir changes over time.
Data Drives Better Oil Well Completions
The rich visualization and analytic capabilities of CoViz 4D, an integrated visualization and analysis software solution, allow drilling and completion engineers to cross-correlate existing data—geologic and reservoir models, petrophysical and log data, cuttings and core data, and seismic with newly-generated borehole data—logs, mud logs, cuttings, drill rate, and hydrocarbon shows. Through collaborative analysis and visual exploration of feasible alternatives for each aspect of the completion, process engineers can leverage CoViz 4D to quickly develop and fine-tune the completion plan—casing, perforations, liners, frac design, and pumps to maximize oil well production in the safest possible manner.
