An Investigation into Present Sand Control Testing Practices for SAGD Wells

  • Author / Creator
    Kotb, Omar
  • Heavy oils and extra heavy oils in Alberta that are currently extracted through thermal recovery primarily employ Steam Assisted Gravity Drainage (SAGD). Sand control devices (SCDs) such as Slotted Liners (SLs) and Wire Wrap Screens (WWSs) have been used extensively in wells producing from unconsolidated formations such as the McMurray and Clearwater formations. Currently, utilization of sand control testing technology in the laboratory is gaining significant attention from the industry due to its ability to assess the performance and design of SCDs. Since 1938, researchers have been developing sand control testing setups to evaluate the performance and develop design criteria for SCDs for different well conditions. However, it was only in the past decade that sand control testing began being employed for SAGD wells. Generally, researchers have aimed to apply sand control testing technologies in SAGD condition with varying setups and procedures to either evaluate comparatively the performance of different SCDs or investigate the effect of one testing parameter on the SCD performance. However, little focus has been given towards examining how the differences in testing setups and procedures affect the results and thus, the conclusions on SCDs performances. This shortcoming can cause significant difficulties in understanding as to what extent each study is simplifying the SAGD conditions and how their results are comparable to other setups.The focus of this study is to improve the understanding of the current SRT setups and procedures in the literature on the sanding and flow performance results of the SCDs in SAGD and identify their limitations. Subsequently, the appropriate improvements are suggested, tested, and evaluated to overcome these limitations. The improvements should be supported either by superior testing performance or better representation of SAGD well-operating conditions based on developing an understanding of sanding in SAGD through a literature review. Another aim of this study is to characterize SAGD reservoir oil sands and improve established techniques for replicating reservoir oil sands for sand control testing purposes.A new sand control testing facility was developed, capable of conducting multiphase flow tests with multi-slot slotted liner coupons under different axial stress magnitudes. A testing procedure was designed to allow the representation of sanding in SAGD conditions while accommodating varying field conditions. The setup was used to evaluate the testing performance by introducing new procedures and testing parameters compared to previous testing practices in the literature. The sanding performance was assessed based on measuring the cumulative sand produced at the end of the test. The pore and slot plugging were evaluated by comparing the pressure responses of the sand-pack and the near-coupon region.The work starts with the characterization oil-sands samples received from the McMurray Formation in the Long Lake field. The characterization was conducted in terms of PSD, grain shape, and mineral composition. Next, the characterization data was used to replicate the oil sand samples using commercial sands. Sieve analysis was conducted to validate the success of the replication process. SRT testing parameters were gradually changed from a prominent testing approach in the literature developed by Hycal labs to the new procedure. The sanding test results indicate that fluid flow rate is the most influential testing parameter in SRT testing followed by the packing technique, stress magnitude, and brine salinity. Analysis of pressure data revealed that the moist tamping packing technique results in a significant increase in porosity and uniformity of the sand-pack. Besides, the effect of stress was found to be small on pressure drop, for the stress ranges in this testing program. Furthermore, lowering the salinity from 10,000 ppm to 350 ppm was found to significantly increase fines migration and production, which led to higher pressure drops across the sample.

  • Subjects / Keywords
  • Graduation date
    Spring 2019
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
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