Wellbore Trajectory Planning For Complex Stress States
Conventional wellbore trajectory planning is commonly based on an Andersonian state of stress [SoS]. Based on various failure criteria the optimum well azimuth and inclination for a specific depth can be determined using stereographic projections of the safe mud weight window. For more complex geologic scenarios where the vertical and horizontal stresses are not principal stresses conventional wellbore trajectory planning has limitations. For an arbitrary non-Andersonian SoS safe trajectory orientations calculated for only a few locations along a well path will not be sufficient when determining an optimal trajectory for the entire well. In this paper a new methodology using the full stress tensor is developed to determine optimal well trajectories for complex in-situ stress scenarios. This study uses a 3D finite element analysis to simulate the SoS based on an integrated 3D MEM. The model yields the complete stress tensor at every location for a planned future well path. Using standard equations to determine the wellbore SoS for inclined wellbores the safe operational pressure window can be determined. This procedure is applied to multiple well trajectories of varying combinations of azimuth and inclination targeting a specific reservoir section.
N. Himmelberg and A. Eckert, "Wellbore Trajectory Planning For Complex Stress States," Proceedings of the 47th US Rock Mechanics / Geomechanics Symposium (2013, San Francisco, CA), vol. 1, pp. 750-759, Elsevier B.V., Jun 2013.
47th US Rock Mechanics / Geomechanics Symposium (2013: Jun. 23-26, San Francisco, CA)
Geosciences and Geological and Petroleum Engineering
Keywords and Phrases
3D-Finite Element Analysis; Complex Stress State; Horizontal Stress; Mud Weight Windows; Optimal Trajectories; Stereographic Projection; Trajectory Orientations; Wellbore Trajectory; Geomechanics; Oil Field Equipment; Optimization; Rock Mechanics; Systems Engineering; Tensors; Trajectories
International Standard Book Number (ISBN)
Article - Conference proceedings
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