Multi-Well Real-Time 3D Structural Modeling and Horizontal Well Placement: An Innovative Workflow for Shale Gas Reservoirs

摘要

Horizontal well performance in shale gas plays is highly dependent on placing the well in the preferred target zone of thereservoir interval. Some operators who drill in shale plays do not have seismic data and depth structural maps. They plantheir horizontal wells with only offset well data. Sometimes, their wells land outside of the preferred target because theyblindly place horizontal wells by using only non-directional gamma ray (GR) log data. For optimal well planning andplacement for optimized production, it is important to minimize uncertainty about reservoir structure and placement.Usually, operators create a depth map from identified markers such as well tops correlated across available wells in thefield.The generated map is limited and often leads to landing laterals outside the target zone, especially when well control isnot ideal. The aim of this paper is to illustrate a method of building structural maps and 3D geologic models for drilling inshale gas reservoirs.This methodology lends itself particularly well (but not exclusively) to the pad drilling approachcommon in shale gas development. The use of logging-while-drilling (LWD) technology can be strategically planned frompad to pad to help mitigate structural uncertainty.Data from 42 horizontal and 6 vertical wells in the project area allowed real-time density image and azimuthal logs to becoupled with vertical offset well information to model the structure along the drilled horizontal well trajectory. The modelintegrated all the well tops and real-time bedding dip information to produce modeled surfaces.The structural model generated during this study can be used for new well landing-point planning with limited true verticaldepth uncertainty and for other fieldwide reservoir characterization. If structure information becomes available from seismicdata, this technique also can be used to update the structural model derived from seismic interpretation, thereby deliveringenhanced structural control of the field.