Gamma-gamma density measurements

The basic response of a gamma-gamma density logging tool and the environmental corrections to that response have been determined. This has been accomplished through the use of test formation data and Monte Carlo modeling. The basic response has been determined for formation densities of 1.6 g/cc to 3.1 g/cc. Environmental corrections have been obtained for a full range of borehole conditions. Mudcake corrections in light mud, barite mud, and hematite mud have been obtained for simulated mudcake thicknesses of up to 0.75 inches. Borehole size corrections have been obtained for mudcake thicknesses of up to 0.75 inches. Borehole size corrections have been obtained for air filled, water filled, and mud filled boreholes with diameters ranging from 6 to 14 inches. The response and corrections have been verified downhole through extensive comparisons with core and gravinometer data.