Identification and investigating of faults and fractures have a vital role in the exploration and development of oilfields. Faults and fractures can make high permeable and porous zones that have a main role in fluid flowing in reservoir rocks. Therefore it is necessary to gain information about geometry and nature of faults in the reservoir. Detection of some faults with a vertical displacement of less than half a seismic wavelength, are very difficult in seismic sections. These type of faults is called small faults or sub-resolution faults. In this study, some geometrical attributes including Curvature, similarity and Thinned Fault Likelihood (TFL) have been introduced to recognize small faults. In order to enhance fault detection, a filter entitled Fault Enhancement Filter (FEF) was used. The proposed methodology have been applied successfully in a case study of the North Sea Field.