Study of the effectiveness of well logging data in the identification of hydraulic fracturing cracks

Abstract

© 2020 International Multidisciplinary Scientific Geoconference. All rights reserved. Geophysical surveys of wells represent a wide range of methods, the rational integration of which make it easier the solution of geological problems. In this article, the authors investigate the issue of identifying the parameters of hydraulic fractures. This method is one of the frequently used methods for increasing well productivity. Modifications of nuclear logging and the possibility of acoustic logging are considered on the example of data before and after hydraulic fracturing in carbonate and sandstone deposits. The use of proppant marked with gadolinium (Gd) allows using neutron methods to register only cracks with a marking substance. As a result of borehole hydraulic fracturing, small secondary cracks form around the well that are not filled with proppant. According to acoustic logging data, fractures near the wellbore can cause significant attenuation of sound signals received after fracturing. Comparison of logging data during the interval of stimulation of inflow before and after fracturing allows determining the productivity of the work and evaluating the length of the fracture along the wellbore, or determining the intervals of proppant penetration. Conclusions about the capabilities of nuclear geophysical methods and acoustic logging to identify cracks resulting from hydraulic fracturing are obtained. The authors noted the weak and strong sides of each of the presented methods. Based on the results obtained, it is possible to draw conclusions about the use of a particular method, depending on the tasks set.