SURFACE CASING DESIGN CONSIDERATIONS WITH EMPHASIS ON THE BASS BASIN

1987 ◽  
Vol 27 (1) ◽  
pp. 363
Author(s):  
P.H. Winchester
Keyword(s):  
Pore Pressure ◽  
Fracture Propagation ◽  
Propagation Theory ◽  
Pressure Testing ◽  
Design Considerations ◽  
Worked Example ◽  
Blowout Preventer ◽  
Casing Pressure ◽  
Volume Estimates ◽  
Effective Design

The main purpose of surface casing and the associated blowout preventer (BOP) system is to contain any well pressure that may be encountered while drilling to total depth or the next casing depth. Not only does this mean that the casing and BOP should be sufficient to withstand the pressure exerted upon them, but also the depth of the casing shoe should be such that the formation will not break down under the influence of this pressure. The latter condition could lead to an internal blowout and subsequent cratering to surface.Design consideration for surface casing must encompass fracture propagation theory, pore pressure and kick volume estimates, and associated casing pressure calculations. A worked example from the Bass Basin gives a safe and effective design when these are applied.These design considerations also have an impact on the procedures for pressure testing casing, BOP, and formation which are valid when compared with the existing statutory requirements of Australia, Norway and the USA.Although the operator is responsible for correct casing design, the various statutory bodies have a role to technically challenge and modify drilling and casing programs, and the procedures outlined give the foundations on which to build an acceptable casing scheme.

Geomechanical Controls on Frac-Hits

2022 ◽  
Author(s):  
Dharmendra Kumar ◽  
Ahmad Ghassemi
Keyword(s):  
Pore Pressure ◽  
Fracture Propagation ◽  
Horizontal Wells ◽  
Operational Parameters ◽  
Modeling And Analysis ◽  
Matrix Deformation ◽  
In Situ Conditions ◽  
Fracture Fluid ◽  
Poroelastic Model ◽  
Element Method

Abstract The communication among the horizontal wells or "frac-hits" issue have been reported in several field observations. These observations show that the "infill" well fractures could have a tendency to propagate towards the "parent" well depending on reservoir in-situ conditions and operational parameters. Drilling the horizontal wells in a "staggered" layout with both horizontal and vertical offset could be a mitigation strategy to prevent the "frac-hits" issue. In this study, we present a detailed geomechanical modeling and analysis of the proposed solution. For numerical modeling, we used our state-of-the-art fully coupled poroelastic model "GeoFrac-3D" which is based on the boundary element method for the rock matrix deformation/fracture propagation and the finite element method for the fracture fluid flow. The "GeoFrac-3D" simulator fully couples pore pressure to stresses and allows for dynamic modeling of production/injection and fracture propagation. The simulation results demonstrate that production from a "parent’ well causes a non-uniform reduction of the reservoir pore pressure around the production fractures, resulting in an anisotropic decrease of the reservoir total stresses, which could affect fracture propagation from the "infill" wells. We examine the optimal orientation and position of the "infill" well based on the numerical analysis to reduce the "frac-hits" issue in the horizontal well refracturing. The posibility of "frac-hits" can be reduced by optimizing the direction and locations of the "infill" wells, as well as re-pressurizing the "parent" well. The results suggest that arranging the horizontal wells in a "staggered" or "wine rack" arrangement decreases direct well interference and could increase the drainage volume.

Jumping on the Digitalization Bandwagon for BOP Pressure Testing

2021 ◽  
Author(s):  
Looi Lai Kheng ◽  
Martin Provan ◽  
Malik Faisal Abdullah ◽  
Eric Hoak ◽  
Gabe Hoke
Keyword(s):  
Operating Cost ◽  
Testing System ◽  
Process Safety ◽  
Offshore Drilling ◽  
Time Saving ◽  
Pressure Testing ◽  
Digital Pressure ◽  
Pressure Tests ◽  
Blowout Preventer ◽  
Drilling Rigs

Abstract Blowout Preventer (BOP) is mainly used to control well pressure by quick well shut in the event of overflow and well kick to prevent blowout on the rigs during drilling, completion, workover, and plug and abandonment phases of well operations. Regulators, Operators and Drilling contractors have put in place the requirement to test BOP systems as a method of inspection and assurance in this process safety critical steps. During well operations regular BOP pressure testing will need to be conducted to ensure its integrity and functionality as per testing requirement. In most cases BOP pressure testing is conducted online using rig time although it can also be conducted offline in some circumstances. BOP Pressure testing is considered flat time during well operations and the operators’ goal is to minimize flat times for rig time saving thus operating cost reduction. Flat time reduction can be achieved by reducing BOP pressure testing period and improving the efficiency in the entire testing process. As such a digital pressure testing system was deployed to multiple offshore drilling rigs in Malaysia beginning in September 2019 as innovative technological solutions. This paper represents the digital pressure testing system deployment study on both subsea and surface BOP drilling rigs for direct comparison with the process in use of the analog circular charter recorders (CCR) for BOP Pressure Testing. The study has shown an average 22% reduction in test times, improved safety, improved efficiency in recognizing failed tests faster, improved data reliability and repeatability of BOP pressure tests.

scholarly journals Using Cohesive Zone Model to Simulate the Hydraulic Fracture Interaction with Natural Fracture in Poro-Viscoelastic Formation

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1254 ◽  
Author(s):  
Yu Suo ◽  
Zhixi Chen ◽  
Hao Yan ◽  
Daobing Wang ◽  
Yun Zhang
Keyword(s):  
Numerical Model ◽  
Pore Pressure ◽  
Hydraulic Fracture ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Fracture Propagation ◽  
Natural Fracture ◽  
Zone Model ◽  
Fluid Viscosity ◽  
Fluid Diffusion

Hydraulic fracturing is a widely used production stimulation technology for conventional and unconventional reservoirs. The cohesive element is used to explain the tip fracture process. In this paper, the cohesive zone model was used to simulate hydraulic fracture initiation and propagation at the same time rock deformation and fluid exchange. A numerical model for fracture propagation in poro-viscoelastic formation is considered. In this numerical model, we incorporate the pore-pressure effect by coupling fluid diffusion with shale matrix viscoelasticity. The numerical procedure for hydraulically driven fracture propagation uses a poro-viscoelasticity theory to describe the fluid diffusion and matrix creep in the solid skeleton, in conjunction with pore-pressure cohesive zone model and ABAQUS was used as a platform for the numerical simulation. The simulation results are compared with the available solutions in the literature. The higher the approaching angle, the higher the differential stress, tensile stress difference, injection rate, and injection fluid viscosity, and it will be easier for hydraulic fracture crossing natural fracture. These results could provide theoretical guidance for predicting the generation of fracture network and gain a better understanding of deformational behavior of shale when fracturing.

scholarly journals GROUND IMPROVEMENT AS ALTERNATIVE TO PILING – EFFECTIVE DESIGN SOLUTIONS FOR HEAVILY LOADED STRUCTURES

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Sondermann Wolfgang
Keyword(s):  
Ground Improvement ◽  
Soil Conditions ◽  
Design Criteria ◽  
Optimal Solutions ◽  
Construction Costs ◽  
Construction Time ◽  
Design Considerations ◽  
Wide Range ◽  
Heavy Loads ◽  
Effective Design

Well-designed ground improvement options without compromising on stringent design criteria may effectively replace conventional foundation solutions for a wide range of applications involving heavy loads and structures sensitive to settlement. Case studies illustrate the application of different ground improvement methods used in different projects and soil conditions by adopting of advanced design considerations to achieve optimal solutions for the project and customer benefit. Beneficial returns in terms of lowering construction costs and shortening construction time with consistency in quality are discussed where applicable in relation to the required capabilities and experiences of an organisation to deliver the alternatives. Opportunity management gives the chance to achieve the project scopes for the client by optimizing cost, time and quality and recommendations are summarised to foster the chance to identify optimal geotechnical solutions.

Inherently safer sustained casing pressure testing for well integrity evaluation

2014 ◽  
Vol 29 ◽  
pp. 209-215 ◽  
Author(s):  
Tony Rocha-Valadez ◽  
Ray A. Mentzer ◽  
A. Rashid Hasan ◽  
M. Sam Mannan
Keyword(s):  
Pressure Testing ◽  
Well Integrity ◽  
Sustained Casing Pressure ◽  
Casing Pressure
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