March Technical Talk

BCGS March Technical Talk – Tuesday March 18th, 2014

Speaker: Sarah Devriese, PhD Student, UBC

Title: Using Electromagnetic Methods to Image SAGD Steam Chambers

Date/Time: Tuesday March 18th, 2014 at 4:30pm.

Location: Room 451, 409 Granville St (UK Building at Granville and Hastings), Vancouver

Abstract:

Steam Assisted Gravity Drainage (SAGD) is an enhanced oil recovery method, used to produce bitumen from oil sands. The success of this technique is dependent upon the propagation of steam throughout the bitumen layer. However, heterogeneity in the reservoir rock can cause the steam to not always propagate as desired. Monitoring the location and growth of steam chambers provides vital information about the production efforts and has traditionally been done using 4D seismic. While successful in many cases, it may be limited by low sensitivity to changes in fluid content, saturation, and porosity. Alternatively, electrical conductivity is significantly affected by the injection of steam into a bitumen layer. Thus electromagnetic (EM) surveys have greater potential in imaging the steam floods while providing higher resolution compared to traditional 2D DC resistivity surveys. The design of an EM survey for monitoring SAGD is crucial in achieving the highest possible resolution at a minimal cost. This talk will introduce a practical methodology for survey design that addresses location and geometry of electromagnetic transmitters. The technique is applied to a synthetic model that emulates the Athabasca oil sands environment and the results are compared to inversions of 2D ERT data. Two-dimensional inversions of the ERT data produce a low quality image with artifacts but the image is improved by carrying out a 3D inversion. However, a superior image is obtained by working with a modest number of transmitters and inverting multiple-frequency EM data in 3D. The results provide optimism for the potential of using 3D EM for imaging subsurface steam chambers.

POST-TALK: Attendees are encouraged to grab refreshments together at Moose’s Downunder afterwards

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