Fractal dimension of well logging curves associated with the texture of volcanic rocks

Abstract

Fractal dimension is usually an effective approach that used to describe the nonregular geometry objects in the nature and nonlinear systems. We investigate the fractal characteristics of well logging curves acquired from Liaohe oil field, China. To calculate the fractal dimension of well logging curves, box-counting method was proposed, we study the method systematically, and calculate the fractal dimension of logging curves using neutron logging(CNL), density logging(DEN), acoustic logging(AC)、 resistivity logging(RLLD) and gamma-ray logging(GR) from 108 wells, 1100m sections with a total of 8800 logging data. Then we found the corresponding relation between fractal dimension of well logging curves and the texture of volcanic rocks. It was observed that the fractal dimension of CNL、 DEN and AC have same value, and the fractal dimension of volcanic lava is lower than the fractal dimension of pyroclastic rock. To validate the accuracy of conclusion, we take X-10 well, 2300-2580m sections for example, describe the relationship between the fractal dimension and the texture of volcanic rock in certain depth. Compare the predicting result of texture of volcanic rocks with core data, the accuracy reaches 90%, our studies demonstrated that the fractal dimension of well logging curves can be applied to predict the texture of volcanic rocks. Keywords-Well logging curves; fractal dimension; box- counting; window technique; volcanic rocks