The fracture network model of Shen 229 block buried hill: A case study from Liaohe Basin, China

Abstract

High oil production from the Proterozoic formation of Shen 229 block in Damingtun Depression, Liaohe Basin, China, indicates the presence of natural fractured reservoir whose production potential is dominated by the structural fracture. A consistent structural model and good knowledge of the fracture systems are therefore of key importance in reducing risk in the development strategies. So data from cores and image logs have been collected to account for the basic characteristics of fracture, and then the analyzed results were integrated with the structural model in order to restrict the fracture network development during the structural evolvement. The structural evolution of the Proterozoic reservoir with time forms the basis for understanding the development of the 3D fracture system. Seismic interpretation and formation correlation were used to build a 3D geological model. The fault blocks that compose the Proterozoic formation reservoir were subsequently restored to their pre-deformation. From here, the structures were kinematically modeled to simulate the structural evolution of the reservoirs. At each time step, the dilatational and cumulative strain was calculated throughout the modelling history. The total strain which records the total spatial variation in the reservoir due to its structural history, together with core data, well data and the lithology distribution, was used to simulate geologically realistic discrete fracture networks. The benefit of this technique over traditional curvature analysis is that the structural evolution is taken into account, a factor that mostly dominates fracture formation.