Well Interaction Detection

Challenge

• In oil sands, on adjacent wells, there is potential for materials to move between wells (“well interaction”)
• Goal is to detect and take action on well communication when it is:
  • Highly desirable – CO2 Enhanced Oil Recovery (EOR), Steam-Assisted, Gravity Driven (SAGD) in oil sands
  • Or undesirable – introducing frack material or stimulant into production wells, or water from poor performing wells to others
• Needed on hundreds of pads, and 1000s of wells

Solution

• Detect: sharp changes in pressure, temperature, conductivity
• Seeq calculation engine used for regression, and signal time offsets
• Using Seeq’s Matlab SDK, systematically search across hundreds of well pairs to find correlations
• Asset structure includes assignment of “neighbor wells”

Benefits

• Identify “offender” wells with undesirable well communication in a SAGD field
• Product quality improvement and reduced processing costs
• Reduce damage SAGD well liners due to steam infiltration
• Energy and material savings (Steam, CO2, chemicals)
• Offset costly consulting services

Data Sources

• Process Data Historian: OSIsoft PI
• Asset Structure: OSIsoft Asset Framework

An AF structure linking “neighbor” wells is developed for systematic detection of relationships between process conditions in wells and their neighbors.

Data Cleansing

• Signals are shifted in time to account for delay and residence time of material migration from “perpetrator” to “victim” wells

Calculations and Capsules

• Relationships between neighbor wells are identified with OLS1 regression analysis of steam injection in “perpetrator” wells and temperature in “victim” wells
• To account for migration delays, signals are shifted in time to identify the true relationship of migration
• Leveraging the Matlab SDK, temperature signals in “victim” wells are systematically shifted 4 hours to 4 days and correlated with steam injection rate of the “perpetrator” wells (Correlation coefficients indicate relevance and rank of importance for review prioritization)

Summarizing Results

• Migration time between “perpetrator” and “victim” wells identified as typically averaging 8 hours, where present
• Well interaction consistently identified when R2 of steam injection/victim well temp (shifted 8 hours) was 0.2 or higher
• Identification of EOR2 material migration can be systematically affiliated with other process occurrences, such as liner degradation or well productivity anomaly data that is overlaid