James Autry (Weatherford)

This presentation is based on the SPWLA paper originally presented during the SPWLA 47th Annual Logging Symposium held in Veracruz,, Mexico, June 4-7, 2006. “Cased Hole Formation Density Logging With A Compact Open Hole Tool, and Implications For Gas Zone Evaluation”  Authors: PAS Elkington, J.R. Samworth, and C.A. Pereira,-Weatherford.

With efficiency being one of the largest drivers in the industry today the need to develop novel techniques of using our current measurements is becoming more critical.  With this in mind the combination of through-casing density and casing-corrected neutron porosity has been applied to the evaluation of by-passed pay and shallow gas, and to the evaluation of wells where open hole acquisition has not been feasible for hole quality, logistical or economic reasons. The tool-specific neutron porosity excavation effect has been characterized for gas-bearing sands.

Case history and model results suggest accurate formation densities are achievable for casing thicknesses up to about 0.35 inches if cement is less than about 1 inch thick, albeit with loss of precision relative to open hole. Formation sensitivity declines with increased cement thickness until practically all is lost for casing standoffs in excess of 1.5 inches. For modest thicknesses, however, cased hole density neutron gas evaluation has advantages relative to the neutron-dipole sonic method; in particular it does not rely on good cement bond, it has generally superior spatial resolution, and (optionally) data can be acquired in memory mode on slickline in operating environments that do not favor conventional wireline units.

James Autry is the Asia Pacific Technical Sales and Support Manager for Weatherford Wireline Services, based in Kuala Lumpur, Malaysia.  He provides Technical, Marketing, and Operational Support for Clients and Field Operations.  He started in the Wireline Industry in 1999 as a field engineer.  Since then he has been involved in various Technical, Sales, and Management Positions. He did his undergraduate studies in Chemistry at The University of Texas at El Paso and graduate work in Chemical Engineering at New Mexico State University.