Wellbore Integrity
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Simulation within a wellbore and surrounding cement of thermal expansion causing radial cracks. Developed by Lawrence Livermore National Laboratory (FEW0191).
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The Wellbore Integrity key technology comprises efforts to improve wellbore construction materials and ensure safe and reliable injection operations as well as long-term containment of CO2 in subsurface reservoirs.

Description

Wellbore Integrity is a key technology area that addresses the need to assess and construct wellbores to ensure safe and reliable injection operations as well as long-term containment of CO2 in the targeted reservoir.

Research Agenda and Challenges

Wellbore materials must be resistant to chemical corrosion from injected fluids, must be sufficiently strong to withstand mechanical stresses associated with injection, and must have good cement bonds to ensure containment.

Specific research pathways for wellbore improvements are:

  • By 2020: Develop new wellbore integrity technologies for early storage formations and CO2 resistant construction materials. Research includes use of wellbore deformation measurements as a diagnostic tool; post-mortem studies of older wellbores; and testing of materials suitable for casing, linings, and cements.

  • By 2030: Develop (1) advanced tools to ensure wellbore integrity in complex formations, such as sub-salt, low strength, and over-pressured conditions as encountered in broad deployment projects; and (2) novel well completion techniques to increase reservoir injectivity without compromising containment.
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GSRA Wellbore Integrity Research Timeline
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NETL-Supported Wellbore Integrity Research

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  Results from a subset of a study are in Michigan and Ohio in which cement bond logs were used to evaluate cement condition around well casing. Developed Battelle Memorial Institute DE-¬≠FE0009367.
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NETL supports projects that are addressing research challenges within the Wellbore Integrity key technology area. Examples of projects supporting this key technology area include: (1) development of a fundamental understanding of how well construction, in situ and applied stresses, and CO2/water interactions enhance or degrade the integrity of hydrodynamic seals with a focus on the behavior of interfaces in the wellbore system (casing/cement, cement/cement, and cement/caprock) that are critical to understanding the long-term performance of wellbore systems; (2) development of improved understanding of the impact of CO2 on the integrity of the cement/rock bond in wellbores to allow project developers to confidently ensure that the CO2 is permanently stored and to contribute to better storage technology through improved stability of the bond between the cement used and the caprock; (3) development of miniaturized muon tracking detectors, capable of fitting in standard boreholes, to map temporal and spatial subsurface density variations; and (4) development of a novel application of a pH-triggered polymer gelant to seal leakage pathways associated with existing wellbores, which are difficult to treat with existing technologies.

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Project workflow and a visual depiction of the algorithm development process to predict long-term leakage risks for CO2-exposed wells. Developed by the University of Louisiana at Lafayette project DE-FE0009284.

The GSRA webpage offers links to detailed information on projects performing research in this area.