Workflow of Fracture Prediction Using Curvature-Related Attributes and a Case Study

Fracture is a kind of important reservoir in petroleum exploration, which usually exist in the carbonate rock or igneous rock. However, it is always difficult to predict the fracture with the seismic data. In this paper, based on curvature attributes, we develop a workflow for the prediction of fractured zone, fracture orientation, and open fractures. We begin with curvature calculation to predict fractured reservoirs and then calculate rose diagrams using curvature data. Fracture orientation is established by comparing the rose diagrams from imaging logs and the analogues from curvature data. We identify two principal orientations and calculate the azimuth intensity in these two directions using the curvature data. As per the crossplots of azimuth intensity in two directions and productivity, the azimuth with good correlation is the open azimuth of fractures. We apply this method to a Kazakhstan oilfield K and predict fractured-vuggy reservoirs in the eastern field and fractured reservoirs in the western field. In accordance with the prediction, there are two groups of fractures, one in a northeast direction and the other in a northwest direction. NE fractures are open in the northern field, and NW fractures are open in the southern field. We suggest two sites for well drilling, which obtain economic oil flow.