Publications

The importance of landing a well in the right position is crucial for the planning and optimum placement of the horizontal section. The challenges in relation to this when landing the well are, but not solely related to: uncertainties due to seismic resolution and to geological variations within the area. The industry common practice to successfully land a well in such challenging areas, is to drill a pilot hole in order to reduce risks and geological uncertainty. This is not only costly but also carries associated risks and is of limited value in geologically complex areas (i.e. no lateral continuity of the reservoir, change in formations thickness, unconformities, etc.). The jobs performed in Australia to date, presented several challenges, such as seismic uncertainty (+/- 20m TVD), a lack of geological markers above the reservoir as well as limited or remote offsets well(s) with respect to the landing point. Additional challenges were: a) requirement to stop 3m TVD above reservoir, without intersecting it due to environmental issues and completion challenges, b) ascertain the reservoir thickness, fluid contacts and formations properties before making a decision on whether to complete the section just dilled and then proceed with the reservoir section. A new generation of LWD Deep Directional Resistivity (DDR) tool with a radial depth of investigation (DOI) in excess of 30m has been in Field Test in Australia since 2012. This unique DOI combined with a multi-layer inversion capability enabled the mapping of reservoirs geometry in terms of formation resistivity, allowing advanced detection and characterization of them, including fluid contacts, before entering the zone of interest. DDR technology has proven its necessity for landing in such environments with the way forward being to eliminate pilot holes meeting the Clients requirements in complex geological environments.