Search results for " drilling"

Adaptive PI Control of Bottom Hole Pressure during Oil Well Drilling

2018

Abstract In this paper, we studied the bottom hole pressure (BHP) control in an oil well during drilling. Today marginal wells with narrow pressure windows are frequently being drilled. This requires accurate and precise control to balance the bottom hole pressure between the pore and fracture pressure of the reservoir. This paper presents three control schemes to stabilize the BHP prole, including proportional-integral(PI) control, PI with feed-forward control and adaptive PI with feed-forward control. The proposed schemes are carried out through simulations on a high-fidelity hydraulic drilling simulator for flow rate changes and BHP set-point changes. In fast set-point changes and flow r…

Measurement of residual stresses by the hole-drilling method: General stress-strain relationship and its solution

1990

Hydraulic vs. Electric: A Review of Actuation Systems in Offshore Drilling Equipment

2016

This article presents a survey on actuation systems encountered in offshore drilling applications. Specifically, it focuses on giving a comparison of hydraulic and electric drivetrains along with detailed explanations of their advantages and drawbacks. A significant number of industrial case studies is examined in addition to the collection of academic publications, in order to accurately describe the current market situation. Some key directions of research and development required to satisfy increasing demands on powertrains operating offshore are identified. The impact of the literature and application surveys is further strengthened by benchmarking two designs of a full-scale pipe handl…

Dependence between aging treatments and residual stresses on composite laminate

2006

International audience; The objective of this paper is to study the influence of residual stresses due to fabrication conditions on the thermomechanical behavior of carbon/epoxy laminate structures (cross ply). These studied laminates have undergone various cycles of thermal aging. The addition of a post-cure cycle after the end of the initial cycle makes it possible to reduce the residual stresses level. The incremental hole-drilling method is used to measure the residual strain in the laminates. These measured strains and the numerical calibration coefficients obtained by the finite element method allow to calculating the residual stress distribution in composite depth. The obtained resul…

Load Torque Estimation Method to Design Electric Drivetrains for Offshore Pipe Handling Equipment

2016

One of the main design objectives for electric drivetrains operating in offshore drilling equipment is to keep them as small, yet as effective, as possible, to minimize space they occupy on drill floor and maximize their performance. However, practical experience shows that typically choices made by design engineers are too conservative due to the lack of enough data characterizing load conditions. This results in too costly and too heavy selected components. Therefore, in the current paper we present a method to estimate required full-scale motor torque using a scaled down experimental setup and its computational model. A gripper arm of an offshore vertical pipe handling machine is selecte…

Review of Some Development of the Hole Drilling Method

1990

This paper contains a survey of some developments of the hole drilling method. It is mainly based on the research work carried out at the University of Palermo in the years from 1978 to 1989. The paper considers the relationship between the relaxed strain and the residual stresses for a rosette with an off-centre hole, the influence of hole eccentricity on the determination of residual stresses and of rosette calibration constants, the sensitivity of strain relaxation.

A new calculation procedure for non-uniform residual stress analysis by the hole-drilling method

1998

The hole-drilling method is one of the most used semi-destructive techniques for residual stress analysis in mechanical parts. In the presence of non-uniform residual stress, the stress field can be determined from the measured relaxed strains using several calculation methods, but the most used one is the so-called integral method. This method is characterized by some simplifications that lead to approximate results, especially when the residual stress varies abruptly. In this paper a new calculation procedure called the spline methods is proposed, which allows these drawbacks to be overcome. Numerical simulations and an experimental test have corroborated the best performance of the prop…

Force Variations on Heave Compensating System for Ultra-Deepwater Drilling Risers

2010

This paper discusses modeling aspects related to dynamic analysis of deep water drilling risers. These risers must have a heave compensator that maintains a near constant tension in the riser independent on platform motions. Traditional riser analysis will apply constant top tension or a simple parametric model that may give approximate tension variation. The present paper describes an alternative analysis procedure that consists of the following step: • Global riser analysis including calculation of dynamic stroke of the heave compensator from platform motions and riser dynamics. A “pipe-in-pipe” approach is used to represent the hydraulic cylinders. • Calculation of dynamic tension variat…

Defect Detection in Additively Manufactured Components: Laser Ultrasound and Laser Thermography Comparison

2018

Despite continuous technological advances in additive manufacturing, the lack of non-destructive inspection techniques during the manufacturing process is a limit for the industrial breakthroughs. Additive manufacturing is mainly used in industrial sectors where the zero defect target is crucial. The inclusion of the integrity assessment into the additive manufacturing process would allow corrective actions to be performed before the component is completed. To this end, the development of in-process monitoring and processing techniques is of great interest.This work proposes and compares two remote non-destructive inspection techniques: laser ultrasound and laser thermography. The two techn…

Error and Uncertainty Analysis of the Residual Stresses Computed by Using the Hole Drilling Method

2010

:  The hole-drilling method is one of the most used techniques for the experimental analysis of the residual stresses in mechanical components. For both through-thickness uniform and non-uniform residual stress distributions, its application is standardised by the ASTM E837-08. In accordance with the ASTM limitations, the analysis of uniform residual stresses, to which the present work deals with, leads in general to results with a maximum bias of about 10%. Unfortunately, in general the user does not have appropriate procedures to estimate the actual stress error; consequently, if one or more of the experimental influence parameters fall out of the corresponding standard limitations, the c…