Abstract
The development well drilling for the deep carbonate reservoir in Shunbei field, located in Tarim Baisn in Northwest of China, has been challenging because of the great depth, complex lithology, highly fractured reservoirs and the stress condition of the field. Although vertical wells could mostly be drilled to over 7,000 m deep by continuous reaming, deviated well drilling turned out to be extremely challenging. These wells are associated with frequent hole instability related issues such as stuck pipe and pack off, which results in sidetracks. To help understand the different drilling behaviors in different parts of the Shunbei field, a pilot area was selected to construct a 3D geomechanical model to understand the lateral variations in stress and rock properties by integrating the spatial structural and lithology changes. A 3D geomechanical model is built using the well-based models as foundation and integrating the surface seismic interpreted surfaces, attributes and velocity volumes. Based on detailed well-centric geomechanical modeling, an understanding of the three principal stresses, pore pressure and rock mechanical properties and parameters of the formations was previously developed at the offset wells locations in Shunbei field. Rock mechanical properties, pore pressure and stresses were populated in 3D space using inverted seismic volumes and relationships developed in the well-centric models, honoring the 3D static geological and structural models. 3D geomechanical modeling is an effective method to capture the lateral variations away from the offset wells and helps to diagnose and understand the drilling problem in the complex deep carbonate reservoir.
