Accurate characterization of the geology of oil and gas fields is an essential aspect of successful field development. Identifying and avoiding or mitigating risks as early as possible reduces development costs. With the wealth of geologic and other subsurface data and efficient analytic software tools, geoscientists can be better informed than ever before regarding the geology of oil and gas fields and its influence on field development. In this blog, we focus primarily on identifying and mitigating geologic risks.
Proactively Identify and Mitigate Geologic Risks
- Over time, active faults and salt domes can threaten wellbore stability, shear casings, and bring production to a halt. Is the problem local, or is it characteristic of the entire field? Should the well be abandoned or is sidetracking a feasible alternative? Once an active fault is identified, future wells can be planned to avoid the active fault.
- Shallow wells pose the threat of subsidence. At what point in field development might subsidence become a problem? How extensive would it be? What mitigation strategies would be most effective, based on knowledge of fields with similar formations?
- Fissures, fractures, and cavities can induce lost circulation during drilling. What well planning strategies would minimize the risk of lost circulation during drilling or cementing?
Integrate and Visualize Data to Understand the Geology Of Oil and Gas Fields
- Integrate seismic interpretations with depth models via geo-model-driven velocity and time-to-depth conversion algorithms.
- Create intermediate horizons using true vertical thickness (TVT) or true stratigraphic thickness (TST).
- Employ geometric reconstructive techniques to represent strata depositional history in faulted reservoirs.
- Show any or all wellbore and outcrop data used in generating a faulted 3D geologic model.
- Comparing and validating various fault and horizon interpretations.
- Displaying individual fault blocks to explore fault structure in greater detail.
- Determining which geologic model layers to display (or hide) so that fault offsets of particular areas can be analyzed.
- Creating cross-sections (perpendicular to the x, y, or z axes) through 3D models and seismic volumes.
- Annotating cross-sections with data from geophysical logs and property distributions within fault blocks.
Visualization facilitates a more detailed understanding of major fault gaps, normal and reverse faults, fault-wedge contours, overthrusts, salt diapirs, stratigraphic discontinuities, and other complex tectonic structures.