Jetting of Structural Casing in Deepwater Environments: Job Design and
Operational Practices

Akers, Thomas Jay

doi:10.2523/102378-ms

Cited by 4 publications

(4 citation statements)

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“…In subsea wells, structural casing must also support the subsea christmas tree and blowout preventer (BOP) stack. Structural casing is jetted in place using practices described by Akers 1 . An inner string and bent housing motor mounted in the shoe assist the jetting operation by removing the majority of the sediment beneath the casing as it is washed down.…”

Section: Riserless Drilling Practicesmentioning

confidence: 99%

Improving Hole Quality and Casing-Running Performance in Riserless Topholes—Deepwater Angola

Akers

2008

IADC/SPE Drilling Conference

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The operator and co-venturers are developing several Angola Block 15 fields in water depths of up to 1400m. To date, 83 development wells and 33 exploration / appraisal wells have been drilled in the Block. Most have experienced hole quality issues in the riserless interval that manifests themselves as tight hole while tripping the BHA and abnormal/excessive drag running casing. In a few cases, casing could not be run to total depth (TD) and in one unfortunate case, the casing buckled in open water.There has been uncertainty as to the root cause of the hole quality issues which have been attributable to various factors since drilling was initiated. A review of available literature revealed very little published information on riserless drilling and casing running practices. The operator undertook a study of its riserless drilling and casing running practices in order to look for trends that may suggest certain sources as the root cause and to allow a re-examination of long-accepted practices. The study, combined with some new perspectives on directional drilling mechanics, has identified potential root causes not previously considered. Changes to drilling practices have resulted in improved riserless hole quality and smoother casing running operations.

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Section: Riserless Drilling Practicesmentioning

confidence: 99%

Improving Hole Quality and Casing-Running Performance in Riserless Topholes—Deepwater Angola

Akers

2008

IADC/SPE Drilling Conference

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“…75 m in diameter, 25 mm thick) for 55 wells in the GoM in water depths ranging between 38 and 131 m (Minton, 1967). In the 1970s, development of tools such as the positive displacement mud motor and the wellhead housing running tool allowed the jetting technique to evolve (Akers, 2008). Today, jetting is successfully performed in water depths well in excess of 1500 m (Evans et al, 2002;Jeanjean, 2002).…”

Section: Well Design and Jetting Operationmentioning

confidence: 99%

“…All the field data indicate the axial capacity of a jetted conductor increases with time during the first 10 days after the installation (Jeanjean, 2002;Akers, 2008), but there is little publicly available information on design, installation records and long-term performance of jetted piles. In general, increases in the axial resistance of a pile after installation have been attributed to the following four factors (Karlsrud, 2012) (a) dissipation of excess pore pressures and gain in horizontal (radial) effective stress (consolidation) (b) thixotropy effects (c) aging effects (d ) multiple unloading and reloading of a pile to near its capacity.…”

Section: Well Design and Jetting Operationmentioning

confidence: 99%

“…The objective is to achieve an acceptable penetration rate while minimising damage to the foundation soils that could significantly affect the set-up and to prevent the conductor from broaching or plugging during the operation. Broaching is caused by a restriction inside the conductor such as pack-off around the jetting BHA or plugging of the exit ports in the wellhead and running tool (Akers, 2008). If broaching occurs inside the conductor, the water makes an alternative path and flows outside the conductor towards the mudline (i.e.…”

Section: Well Design and Jetting Operationmentioning

confidence: 99%

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Long-term axial capacity of deepwater jetted piles

Zakeri¹,

Liedtke²,

Clukey³

et al. 2014

Géotechnique

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Jetting is a technique commonly used to install well conductors, which is faster than the conventional drill and cement method. Conductors are designed to support the buoyed weight of the first string of casings (typically, 3-5 days after jetting) and later to provide the lateral stability for the well system against cyclic loading from environmental elements. The axial bearing capacity of a jetted conductor increases with time due to consolidation and thixotropy effects; however, the field data for set-up only extend to about 10 days. Installation of jetted conductors as piles and anchors may be an economic solution for offshore developments. The long-term axial capacity of jetted conductors was investigated through a series of centrifuge modelling and laboratory thixotropy testing. The centrifuge tests simulated jetting installation of four model conductors and measured capacities at set-up times ranging between 10 and 1000 days in a kaolin clay seabed with an undrained shear strength profile similar to that encountered in deepwater Gulf of Mexico. The centrifuge test results were compared to the field data in the Gulf of Mexico. The implications of the centrifuge test results for deepwater Gulf of Mexico conditions are discussed. A method is presented for estimating the long-term axial capacity of jetted conductors in Gulf of Mexico seabed conditions with recommendations for additional studies.

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Calculation of side friction resistance between the formation and conductor during the jetting process in deepwater drilling

Yang

Xiang

et al. 2018

Marine Georesources & Geotechnology

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Jetting of Structural Casing in Deepwater Environments: Job Design and Operational Practices

Cited by 4 publications

References 0 publications

Improving Hole Quality and Casing-Running Performance in Riserless Topholes—Deepwater Angola

Improving Hole Quality and Casing-Running Performance in Riserless Topholes—Deepwater Angola

Long-term axial capacity of deepwater jetted piles

Calculation of side friction resistance between the formation and conductor during the jetting process in deepwater drilling

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