The initial development phase of conventional oil and gas plays often delivers less than 50% of recoverable hydrocarbons. The majority of today’s oil and gas production comes from mature wells. Current oil prices do not encourage the exploration and development of new fields.
These factors motivate operators to look for economic means to extend the field’s productive life. Improvements in oilfield technology, the increasing variety and volumes of data acquired throughout the life of an oilfield, and data integration and visualization software are helping reservoir teams better assess oil and gas reservoirs and guide mature oil field secondary and tertiary recovery.
Evaluating Mature Oil Field Conditions
Ultimately, mature oil field redevelopment is an economic decision that is best made with extensive reliance on data. Reservoir simulation models updated with the latest production, petrophysical, and geologic data can provide a current estimate of remaining oil and gas.
Historical production data from individual wells, as well as aggregate reservoir analysis, visualized in the context of the latest seismic survey, can point to reasons for production decline. Did a well water-out faster than expected? Was a well produced too fast? Is coning the source of the decline? Did certain regions experience faster decline than others or are all wells underperforming? Accurate answers to these questions often require access to a wide range of data sources.
Data Integration and Visualization: Critical for Mature Oil Field Redevelopment
The ability to integrate, visualize, and analyze all relevant reservoir data—seismic, geophysical, petrophysical, reservoir simulations, well logs, completions, production—helps reservoir teams collaboratively assess conditions, diagnose problems, identify bypassed oil, and begin to explore and evaluate mature oil field stimulation options by:
- combining historical production data with structural, stratigraphic, and seismic mapping to identify well sites with the greatest potential
- evaluating geophysical properties, formation pressures, and in-situ stresses to develop drilling strategies to access untapped zones in depleted, multilayered reservoirs
- reviewing development and production history of nearby fields to learn which strategies and techniques positively impacted mature oil field redevelopment
Reservoir teams gain additional insight when these data are integrated and visualized to depict the oil field development over time (4D). Animation shows how production and decline in an oil field evolved as new wells were drilled and production volumes, (gas, oil, water) varied in response to new wells.
Animating data across time (4D) shows how development and operational decisions have impacted well production. Green = oil, blue = water, orange = injector well.
A 2D graph plots only a few data variables. A 3D snapshot better depicts subsurface conditions. A 4D analysis enables individual members of a reservoir team to review reservoir development and performance in a compressed time period to see how past development and operational decisions have affected reservoir production. This temporal analysis can generate insights that may otherwise go unnoticed, and guide reservoir engineers in making mature oil field redevelopment decisions that maximize production and recovery.
Data Visualization and Analysis Drive Mature Oil Field Redevelopment Decisions
With a collaborative, interdisciplinary analysis of a mature oil field facilitated by 3D and 4D
visualization, reservoir engineers are far better prepared to determine the appropriate EOR strategies and techniques. Reviewing production history, evaluating property averages and attributes in seismic space and cellular space, or updating reservoir models via a 4D seismic history matching workflow can reveal previously unrecognized recovery opportunities, that may include:
- Temporarily idle a well to increase production from nearby wells.
- Identify a new injection site to enhance the current waterflood strategy and boost production.
- Locate areas where infill drilling presents the best method to enhance recovery.
- Apply previously unused EOR recovery techniques such as gas, iWAG displacement, chemical (polymer, dilute surfactant, or micellar), or thermal injection wells.
- Initiate proppant-intensive fracture treatments for existing wells or new wells.
Mature oil field redevelopment offers an economically-feasible, relatively low-risk route for improving production when investments are constrained. However, to maximize recovery reservoir teams need to take advantage of the wealth of oil field data available.
To maximize recovery reservoir teams need to take advantage of the wealth of oil field data available.
Software Is Critical
Software solutions developed for the petroleum industry play a critical role in integrating the diversity of discipline-specific data sources associated with oil field development and production. Once integrated, those data can then be visualized and analyzed to diagnose declining production problems, determine appropriate EOR methods, as well as identify previously unrecognized areas for potential development. Data integration and visualization tools significantly enhance a reservoir team’s ability to analyze the complex factors affecting oil field decline and collaboratively develop cost-effective strategies to extend the production life of an oil field.