Perforation drilling for easing spudcan–footprint interaction issues

Hossain, Muhammad Shazzad; Stainforth, R.

doi:10.1016/j.oceaneng.2016.01.002

Cited by 17 publications

(12 citation statements)

References 20 publications

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“…It is worth noting that H and M first increase and then decrease as the depth increases, and their peak values do not occur at the bottom of the footprint, but at a shallower depth. It is also shown that H and M are significantly reduced by the perforation drilling, which is consistent with the conclusions of Hossain and Stainforth [21].…”

Section: Model Validationsupporting

confidence: 91%

“…Although Hossain and Stainforth [21] proved the effectiveness of perforation drilling in easing spudcan-footprint interaction, effects of the borehole diameter, number, depth, and range on the mitigation efficacy are still unclear. To study their effects, five series of numerical simulations were conducted, with the parameters listed in Table 2.…”

Section: Resultsmentioning

confidence: 99%

“…Based on previous researches on footprint geometry, the footprint dimensions are selected as 2D wide and 0.33D deep for clay deposit. Additionally, the footprint has a conical shape with a slope angle θ of 18.5 • , which represents the upper bound of the profiles recorded in previous tests (Hossain and Stainforth [21]). The perforation boreholes are drilled around the footprint with a depth of h hole .…”

Section: Introductionmentioning

confidence: 81%

“…The numerical model is validated against the 1 g test carried out by Hossain and Stainforth [21]. In the test, the perforation drilling holes formed a pattern of four circles which are concentric to the spudcan, with the diameter ranging from 0.9D to 1.2D (see Figure 1).…”

Section: Model Validationmentioning

confidence: 99%

“…For the other category, the "perforation drilling" technique was proposed as a measure of seabed reconstruction, by weakening the bearing capacity of the soil outside the footprint which reduces the eccentricity of the soil under the spudcan. Hossain et al [20] and Hossain and Stainforth [21] conducted preliminary tests on the "perforation drilling" through experiments and verified the effectiveness of the method in mitigating the sliding risk. Although it has not been successfully implemented in engineering practice to reduce sliding risk, its feasibility to mitigate the punch-through risk in layered clays has been verified in the field [22,23].…”

Section: Introductionmentioning

confidence: 99%

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Mitigation Effect of Perforation Drilling on the Sliding Risk during Spudcan Installation Close to Footprints

Gao

Liu

Shi

et al. 2020

JMSE

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Perforation drilling is a promising technique to mitigate the sliding risk of jack-up units installed around footprints. Based on the coupled Eulerian–Lagrangian (CEL) method, a 1/2 finite element model, including a rigid Lagrangian spudcan and a Eulerian soil part, was established, and the contact interface was modelled with the Coulomb friction model. Validated against an indoor perforation test, the model was adopted to investigate the mitigation mechanism and effects of the borehole diameter, number, depth, and the drilling range. The simulations reveal that the mitigation efficiency increases with the borehole diameter, number, and depth. However, it shows little improvement if the borehole depth increases beyond double footprint depth. The semi-drilling at the outer side of the footprint is a little more effective than the full-drilling at both the inner and outer sides of the footprint. The present work emphasizes the effects of perforation drilling parameters on the mitigation efficiency, which are of great significance to guide the engineering practice and guarantee the safe operation of the jack-up reinstallation close to existing footprints.

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Section: Model Validationsupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 81%

Section: Model Validationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Mitigation Effect of Perforation Drilling on the Sliding Risk during Spudcan Installation Close to Footprints

Gao

Liu

Shi

et al. 2020

JMSE

View full text Add to dashboard Cite

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Encyclopedia of Maritime and Offshore Engineering

Talas¹,

Menachof

Harris³

2017

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Spudcan–Seabed Interaction

Bienen

Hossain

2018

Encyclopedia of Maritime and Offshore Engineering

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Most offshore drilling in shallow to moderate water depths is performed from self‐elevating jack‐up rigs due to their proven flexibility, mobility, and cost‐effectiveness. Today's jack‐ups typically consist of a buoyant triangular platform supported by three independent truss legs, each attached to a large 10–20 m diameter spudcan, which are jacked into the seabed. These transfer the loads from the platform to the seabed soil. This article provides an overview of the state of practice of geotechnical design considerations for spudcan–seabed interaction, covering the full life cycle including (i) installation, (ii) operation, and (iii) demobilization.

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Perforation drilling for easing spudcan–footprint interaction issues

Cited by 17 publications

References 20 publications

Mitigation Effect of Perforation Drilling on the Sliding Risk during Spudcan Installation Close to Footprints

Mitigation Effect of Perforation Drilling on the Sliding Risk during Spudcan Installation Close to Footprints

Encyclopedia of Maritime and Offshore Engineering

Spudcan–Seabed Interaction

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