BCGS Fall Symposium: Oct 16 & 17, 2014

The BC Geophysical Society, in cooperation with Hudbay, is proud to present a two-day symposium on the discovery of the Lalor Deposit. The amount and variety of geophysical work undertaken, coupled with the geological understanding and insight provided by the owner of this prominent deposit, is sure to make this an extremely interesting session.

Additional details including the full speaker schedule will be available this summer. Registration is scheduled to open August 2014.

Exploration for Deep VMS Ore Bodies: The Hudbay Lalor Case Study

When: October 16 and 17, 2014

Where: BCIT Downtown Campus, Vancouver, BC

Cost: Industry $150 / Students $50

Please see the following link to the symposium abstract for additional details.

Lalor Symposium Abstract – June 11 v2

BCGS Exec

 

KEGS Foundation Scholarship Deadline – April 30, 2014

Every year the BCGS proudly supports the KEGS Foundation Scholarship program by donating revenue from the yearly symposium.

The deadline for the 2014/2015 scholarship program is April 30, 2014. We encourage students (particularly undergraduates) to apply before the upcoming deadline. Please see the attached poster for additional information.

KEGSF14c9.Schol Announcement Poster 2014-2

April Technical Talk

BCGS April Technical Talk – Thursday April 17th, 2014

Speaker: Peter Fullagar, Fullagar Geophysics

Title: 3D magnetic modelling and inversion incorporating self-demagnetisation and interactions

Date/Time: Thursday April 17th, 2014 at 4:30pm.

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

Abstract:

Self-demagnetisation can significantly reduce the amplitude and modify the shape of the response from highly magnetic bodies. The direction of magnetisation rotates in a manner determined by the shape and orientation of the body. Furthermore, when highly magnetic bodies are in close proximity, the magnetisation induced in one body is affected by the magnetisations in all the others. When modelling highly magnetised bodies, it is important to take both self-demagnetisation and interactions into account. Inverting for magnetisation vector has become popular recently. However, this is not a substitute for physically valid magnetic modelling. Magnetisation inversion is highly nonunique, with the result that any particular solution must be interpreted with care. An inverted magnetisation rotated from the ambient field is not necessarily indicative of remanence. Moreover, relating an inverted in situ magnetisation to rock properties is often problematic. In this respect, magnetisation inversion complicates ground truthing. Potential field modelling and inversion software “VPmg” has been upgraded to account for self-demagnetisation within, and interaction between, 3D magnetic bodies. Remanence can be taken into account. The algorithm computes H-field perturbations at the model cell centres in two stages: initialisation and optimisation. During initialisation, a first estimate for the H-field perturbation is derived from the demagnetisation tensor computed for each cell.

During optimisation, the H-field perturbation is refined iteratively via an inversion procedure. The algorithm has been validated for homogeneous spheres, spheroids, slabs, and cylinders. It has also reproduced magnetic interactions between two horizontal cylinders, published by Hjelt (1973). Explicit verification for complex heterogeneous bodies requires a suitable independent algorithm for benchmarking. The application to inversion in highly magnetic environments is illustrated on field data examples.

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

KEGS/BCGS Roundup Breakfast Registration Info

KEGS/BCGS Roundup Breakfast – TUESDAY, JANUARY 28th 2014

Location: White Spot Restaurant, 1616 West Georgia Street, Vancouver, B.C.

Time: 7:30am

Speaker: Peter Kowalczk, P.Geo, CEO & Director , Ocean Floor Geophysics Inc.

Topic: Non-military geophysics, ships and subsea vehicles and the search for minerals in the deep ocean

Registration: Required in advance by January 22nd 2014.  Online at My KEGS or via the registration form (link below) and emailed to: mickiallen@marac.com

 KEGS_2014_BCGS_Breakfast_Form

Abstract:

Exploration for Submarine Massive Sulfide (SMS) deposits has evolved into a regular process of regional ship-borne work followed by more localized mapping and resource evaluation campaigns using autonomous underwater vehicles (AUVs) and Remotely Operated Vehicles (ROVs) over favourable areas.  There is an established body of operating skills that is now moving from specialized niches in the military, salvage and academic environment into routine application on commercial mineral exploration cruises.  Exploration no longer depends upon the opportunistic mapping of deposits found during research cruises but is instead a systematic and cost effective process using a package of established best practices. Robotic geophysical systems are central to the exploration process at all stages. 

The challenge going forward is to rapidly assess the tonnage potential and grade of a deposit   A number of trial mining systems have been built and are presently being tested. 

Ongoing work by national organizations and by private venture mining companies has a relatively low profile, but is ongoing and moving steadily towards the development of operating mines.