Integration of borehole geophysical data in 2D and 3D to develop a hazard index

Abstract

A borehole hazard index is the integration of interpreted risk indexes with an existing geological and structural 3D mine or exploration model. Individual risk indexes are produced and combined with the purpose of providing a clear visual and quantitative method for determining varying degrees of risk associated with development through a particular geological rock volume. Disparate data sets are used to characterize separate risk indexes established from user defined criteria. Input data sets include geological and structural logs and mine layouts, complemented by a borehole geophysical suite including borehole radar, optical & acoustic televiewers, density, neutron, flowmeter and full wave form sonic. The user defined criteria are established for individual project requirements and can include factors such as the intersection of structures, the presence of water ingress, proximity to structures with specific orientations and the presence of lithological units prone to failure. The requirements of the integration environment vary; certain criteria can be adequately assessed in a 2D environment while other hazard indexes require data to exist in a true topological 3D environment where spatial queries can be performed. The applications of a borehole hazard index include shaft site evaluations, and shaft sinking development planning. Additionally a hazard index can serve as a mine production tool, evaluating hazards in front of the face which will affect both safety and production rates. Successful deployment requires regular and timely update of the local structural model which can be achieved by automating the hazard index generation once the starting model has been defined.