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

Akers, Thomas Jay

doi:10.2118/102378-pa

Cited by 33 publications

(6 citation statements)

References 6 publications

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“…Deepwater mudline's shallow formations typically comprise seabed silt, clay, silt-sand, and sandy mud strata [3]. These poorly lithified formations consist primarily of cohesive and sandy soils of relatively low strength [4,5]. Given the severe conditions in deepwater marine environments, there is an increased need for longer, stiffer surface conductors to bear the augmented volume and weight of the drilling riser and the blowout preventer assembly [6].…”

Section: Introductionmentioning

confidence: 99%

Research on Lateral Load Bearing Characteristics of Deepwater Drilling Conductor Suction Pile

Li,

Yang,

Zhu

et al. 2024

Energies

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The vast reserves of natural gas hydrates in offshore areas present significant challenges to development. Surface well construction technology is crucial for the extraction of deepwater natural gas hydrates. To ensure the safety of the subsea wellhead during the drilling process for deepwater natural gas hydrates, a novel conductor suction pile device has been designed, comprising a combination of suction piles and surface conductors. And research has been conducted to investigate the lateral stability characteristics of the conductor suction pile. Drawing upon the pile foundation load-bearing theory and the equilibrium of the differential element, a theoretical analysis model and corresponding governing equations of the conductor suction pile system are established. A solution for a multi-point boundary value problem by simplifying the conductor suction pile system into a two-end free beam is proposed. The governing equations are then converted into a first-order differential equation system, and the four-stage Lobatto IIIa collocation method program for the multi-point boundary value problem is developed and resolved using MATLAB 2023a. Furthermore, a case study of a well in the South China Sea elucidates the effects of wellhead load and seabed soil properties on the lateral load-bearing capacity of the conductor suction pile system, verifying the collocation method’s validity against the results from the finite difference method. After conducting a comparative analysis of the lateral load-bearing performance between conductor suction piles and traditional surface conductors, it is observed that conductor suction piles exhibit lower horizontal displacement and bending moments compared to surface conductors. Therefore, conductor suction piles demonstrate a substantial safety margin. The research findings provide a theoretical basis for the lateral stability of conductor suction piles during deepwater natural gas hydrate drilling. This offers a safe and efficient method for surface well construction in the extraction of natural gas hydrates.

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Section: Introductionmentioning

confidence: 99%

Research on Lateral Load Bearing Characteristics of Deepwater Drilling Conductor Suction Pile

Li,

Yang,

Zhu

et al. 2024

Energies

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“…This precipitates a pressing inquiry: how can we satiate future energy exigencies while concurrently alleviating our reliance on the finite reservoirs of traditional energy sources? The realm of deepwater drilling emerges as a beacon of hope in grappling with this exigency [1,2]. Deepwater regions enshroud vast, untapped reservoirs of petroleum and natural gas.…”

Section: Introductionmentioning

confidence: 99%

Deepwater PDC Jetting Bit-Drilling Technology Based on Well Structure Slimming

Zhang,

Gao,

Zeng

et al. 2023

Energies

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Growing global energy demand and limited reserves of traditional energy resources are causing a growing energy shortage. In order to meet future energy needs, new energy resources must be continuously explored. Deepwater drilling research has emerged as one of the key ways to address this issue, and well structure slimming is an effective way to increase drilling speed and reduce costs. The hole size of the second section of deepwater wells decreases from a conventional 660.4 mm to 444.5 mm and increases from 500–800 m to 800–1200 m, creating problems where the conventional 660.4 mm cone bit cannot be used, the rate of penetration (ROP) of the cone bit is low, and the service life is short. To solve these problems, a 444.5 mm artificial polycrystalline diamond compact (PDC) was designed for the first time for use at home or abroad, and according to the characteristics and operation requirements of the 914.4 mm conductor jetting process, a unique anti-collision gauge protector was designed, an innovative bypass nozzle was configured, and a hydraulic design to prevent bit balling in shallow soft mudstone was formulated. PDC jetting bit-drilling technology based on well structure slimming was successfully applied to eight deepwater wells in the eastern South China Sea, which successfully jetted a 914 mm conductor and greatly improved the ROP of their second-section holes. When the below-mudline depth of the second-section hole increased by 37.01%, the average ROP increased by 227.84%. These technical achievements have successfully realized deep drilling with seawater, increased speed and efficiency, achieved good application results, and accumulated valuable experiences that can be used for reducing the cost and increasing the efficiency of offshore drilling operations.

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“…At present, many scholars have carried out research on the bearing capacity of the conductor. The static mechanical behavior has been studied to calculate the lateral bearing characteristics in soft clay formation [3][4][5][6][7][8]. With the gradual increase in the water depth, the dynamic load on the drilling riser becomes more and more complex.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation Analysis on the Lateral Dynamic Characteristics of Deepwater Conductor Considering the Pile-Soil Contact Models

Wang

Gao

Meng

2022

JMSE

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It is important to accurately assess the interaction between the conductor and the soil to ensure the stability of the subsea wellheads during deepwater drilling. In this paper, numerical simulations were carried out to study the lateral dynamic bearing capacity of the conductor considering different contact models between the conductor and the soil. In particular, the contact surface model and contact element model were selected to study the dynamic behavior of pile–soil under a transverse periodic load. On this basis, the influence of the bending moment, the wellhead stick-up, the outer diameter (O.D.) of the conductor and the wall thickness (W.T.) of the conductor, as well as the physical parameters of the soil on the dynamic bearing capacity are discussed in detail. Analysis results show that the lateral deformation, deflection angle and von Mises stress calculated by the contact element model are greater than those calculated by the contact surface model. The maximum value of the lateral deformation and bending moment of the conductor decrease with the O.D. and W.T. of the conductor, and the cohesion and internal friction angle of the soil. However, the maximum value of the lateral deformation and bending moment of the conductor increase with the wellhead stick-up. Both the vertical force and the soil density have a negligible effect on the lateral behavior of the conductor. This study has reference value for the design and stability assessment of subsea wellheads.

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

Cited by 33 publications

References 6 publications

Research on Lateral Load Bearing Characteristics of Deepwater Drilling Conductor Suction Pile

Research on Lateral Load Bearing Characteristics of Deepwater Drilling Conductor Suction Pile

Deepwater PDC Jetting Bit-Drilling Technology Based on Well Structure Slimming

Numerical Simulation Analysis on the Lateral Dynamic Characteristics of Deepwater Conductor Considering the Pile-Soil Contact Models

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