Formation Breakdown Prediction for the Implementation of Hydraulic Fracturing on a HPHT Tight Gas Reservoir in Oman

摘要

The increased global demand for new hydrocarbon resources leads to the exploration in more challenging environments such as shale gas, tight gas and coalbed methane, where hydraulic fracturing is the key technology to unlock the development of these unconventional resources. In Oman, the challenges imposed by HPHT tight gas formations takes the implementation of hydraulic fracturing to the limits imposed not only by the available fracture technology but by the integrity of the completion components. These challenges increase when stress regime variations are strongly influenced by tectonics. Understanding and predicting the breakdown pressure profile (BDP), and its variability across the target zone, is fundamental for the successful implementation of hydraulic fracturing on tight gas formations. This paper presents the comprehensive work performed for the integration of log derived data with laboratory rock characterization and field observations, leading to the definition of a BDP prediction methodology for tectonically stressed tight gas formations. Key aspects used as integral part of the methodology of the data acquisition and integration are discussed in detail, including the correlations defined between the BDP, formation injectivity variations and tectonics. It also discusses how understanding the variations of BDP across selected intervals provides essential information to assess the identification of fracture initiation zones, perforations and hydraulic fracture strategies as well as completion design requirements, leading this to support the successful implementation of hydraulic fractures and further field development.