scholarly journals Influence of Chemical Corrosive Environment with H2S on Drill Strings, Experimental Researches

2020 ◽  
Vol 71 (4) ◽  
pp. 29-37
Author(s):  
Mihaela Madalina Caltaru ◽  
Marius Badicioiu ◽  
Alin Dinita ◽  
Dragos Gabriel Zisopol ◽  
Razvan George Ripeanu ◽  
...  
Keyword(s):  
Brittle Fracture ◽  
Fatigue Cracks ◽  
Drill String ◽  
Oil Field ◽  
Corrosive Environment ◽  
Inner Surface ◽  
Drill Pipes ◽  
Corrosive Environments ◽  
Experimental Researches ◽  
Diffusion Of Hydrogen

The present researches established the failure causes of the drill string, used in corrosive environments with H2S, in an oil field, by initiating fatigue cracks from the corrosion points on the inner surface of the drill pipes, which favoured the diffusion of hydrogen, the brittleness of the material and the brittle fracture.

Fatigue of structural materials in corrosive environments

2020 ◽  
pp. 56-60
Author(s):  
G.V. Pachurin ◽  
A. A. Filippov ◽  
D. A. Goncharova ◽  
A.N. Kuzmin
Keyword(s):  
Cyclic Loading ◽  
Structural Material ◽  
Fatigue Cracks ◽  
Metals And Alloys ◽  
Corrosive Environment ◽  
Deflection Curve ◽  
Operation Conditions ◽  
Factors Influencing ◽  
Corrosive Environments ◽  
Selection Of

The factors influencing the fatigue failure of metals and alloys are investigated. To increase the resource and reliability of products made of metals and alloys, taking into account their operation conditions and the presence of a corrosive environment, when justifying the selection of a structural material, it is proposed to take into account its deflection curve under cyclic loading. Keywords: structural material, corrosive environment, fatigue resistance, fatigue cracks, deflection curve, cyclic loading, durability. [email protected]

scholarly journals Experimental Analysis of Reinforcement Rust in Cement under Corrosive Environment

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 241
Author(s):  
Xiaozhen Li ◽  
Hui Wang ◽  
Jianmin Wang ◽  
Junzhe Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Steel Corrosion ◽  
Corrosion Products ◽  
Chloride Salt ◽  
Corrosive Environment ◽  
Cement Slurry ◽  
Passivation Film ◽  
Chloride Environment ◽  
Corrosive Environments ◽  
Structural Layer

In this work, the microstructure characteristics of corrosion products of reinforcement under a corrosive environment with chloride, carbonation and the combination of chloride-carbonization were studied by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy/energy spectroscopy (SEM-EDX). The results indicate that the outside of the passivation film reacts with the cement slurry to produce Fe–SiO4 in all three corrosive environments. The inner side is not completely corroded. The morphology of the corrosion is different in the three environments. In a chloride environment, corrosion products have obvious cracks, and the local layered structure is dense. In a carbonation environment, the surface of the steel corrosion shows a uniform granular structure and loose texture. With the combination of chloride and combination, the surface of the structural layer of steel corrosion was uneven and accompanied by protrusions, cracking and spalling occurred. The composition of the corrosion substances in the three corrosion environments are mainly composed of FeO, Fe3O4, Fe2O3 and Fe–SiO4. The content of iron oxide increases from a chloride salt, carbonization to the composite environment, indicating that the corrosion degree intensifies successively.

New Methodology of Slot Recovery Minimizing Milling Operation

2021 ◽  
Author(s):  
Ryosuke Sato ◽  
Islam Khaled Abdelkarim ◽  
Abdul Rahman Hasan Albeshr ◽  
Takahiro Toki ◽  
Salim Abdalla Al Ali ◽  
...  
Keyword(s):  
New Technologies ◽  
Applied Pressure ◽  
Drill String ◽  
Rotary Table ◽  
Actual Case ◽  
Milling Operation ◽  
Drill Pipes ◽  
Pulling Force ◽  
Complete Operation ◽  
Typical Method

Abstract Slot recovery operation can be considered as one of the most time consuming operation. Cut and pull casings, or milling casings have been carried out as typical method of slot recovery. However there are a lot of risks with this typical method such as poor progress of milling, damaging top drive due to high vibration while milling or sudden string jumping up while overpulling and possibility of string stuck caused by poor hole cleaning while milling. We have completed slot recovery operations on numbers of wells, but there were a lot of troubles caused by above mentioned adversaries on rig equipment and taking a lot of time to complete operation. There are several kinds of new slot recovery technologies that may save rig time and less harmful than conventional method. Casing Pulling Tool (CPT) is one of the new technologies which eliminates or mitigates risks mentioned above. CPT has piston internally and it is activated by applying pressure inside string. CPT is run with casing spear and drill pipes. Once spear is engaged with casing and apply pressure inside drill string, CPT provides pulling force on casing. Pulling force is varied depend on the applied pressure and maximum available pulling force is more than 1,000 kips. Hence upper part of string is anchored at rotary table by slips, pulling force is applied on casing and drill string below rotary table. This means no pulling force is applied on top drive and minimize the chance of getting damage on it. As an actual case, we could successfully recover 13-3/8" casing by CPT without having any troubles and complete slot recovery operation with saving rig time compared to the conventional methods. This paper introduces the details about the case mentioned above.

Research on Hydraulic Self-Enhancement Technology of Fracturing Pump’s Valve Box

2012 ◽  
Vol 479-481 ◽  
pp. 2076-2081
Author(s):  
Fa Guang Jiang ◽  
Zheng Liang ◽  
Guang Hui Zhao ◽  
Pan Wang ◽  
Liang Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Service Life ◽  
Material Property ◽  
Fatigue Cracks ◽  
Treatment Method ◽  
Oil Field ◽  
Structural Size ◽  
Enhancement Technology ◽  
Horse Power

It is very important to process acid and fracturing treatment in oil field to improve permeability. The fracturing pump is one of the key equipment for Acid and fracturing treatment. The valve box of fracturing pump is fundamental, costly and wearing parts. Based on the data from domestic and abroad, the life of the valve box is short. Fatigue cracks caused by alternating stress and erosion account for the most invalidation of the valve box. Only increasing structural size and improving material property are not efficient to prolong service life. Related studies show that hydraulic self-enhancement technology is an effective method and it is used widely to improve service life of fracturing pump’s hydraulic parts. Here hydraulic self-enhancement process was simulated by finite element method and 600 Horse Power fracturing pump was studied. The optimal self-enhancement pressure and loading-unloading treatment method are suggested. This study offers a method to found valve box's production technics by hydraulic self-enhancement technology.

Safe Operation of Jacket Platforms in a Major Oil Field in the North Sea

2018 ◽  
Author(s):  
Ingar Scherf ◽  
Trine Hansen ◽  
Gudfinnur Sigurdsson
Keyword(s):  
Emergency Preparedness ◽  
Structural Integrity ◽  
Fatigue Cracks ◽  
Regulatory Compliance ◽  
Offshore Structures ◽  
Oil Field ◽  
Inspection Planning ◽  
Original Design ◽  
Safe Operation ◽  
Integrity Management

Offshore Structures operate for decades in extremely hostile environments. It is important during this period that the structural integrity is efficiently managed to ensure continuous and safe operation. Increased use of enhanced oil and gas recovery means it is likely that many existing installations will remain operational for a significant period beyond the original design life. The operator needs to capture, evaluate and, if necessary, mitigate design premise changes which inevitably occur during the life of a structure. Further, advances in knowledge and technology may imply changes in codes and standards as well as in analysis methodologies. Changes in corporate structures, transfer of operator responsibility and retirement of experienced engineers call for reliable means to transfer historical data and experience to new stakeholders. Effective emergency preparedness capabilities, structural integrity assessments and inspection planning presuppose that as-is analysis models and corresponding information are easily accessible. This paper presents an implementation of the in-service integrity management process described in the new revision of NORSOK standard N-005 [1] for a large fleet of jackets at the Norwegian Continental Shelf. The process, comprising management of design premise changes as well as state-of-the-art technical solutions over a range of disciplines, has enabled the operator to prolong the service life with decades at minimum investments. A structure integrity management system (SIMS) has been developed and digitized over years and streamlined to meet the needs and challenges in the operation and management of the jacket platforms. SIMS enables a rather lean organization to control the structural integrity status of all load-bearing structures at any time. Platform reinforcements and modifications along with other operational risk reducing measures like unman the platforms in severe storms enable continued use with the same level of safety as for new manned platforms. Advanced analyses are used to document regulatory compliance. Modern fatigue and reliability based inspection planning analyses have reduced the costs needed for inspection of fatigue cracks significantly. The benefits from the SIMS system are substantial and the resulting safety and productivity gains are apparent. The continuity of knowledge and experience is maintained, reducing risk to safety and regularity. The digital transformation related to management of structural integrity status as described in NORSOK standard N-005 is realized through SIMS.

Fatigue Assessment of Drill Pipes

2017 ◽  
Author(s):  
P. J. Haagensen ◽  
T. I. Grøttum
Keyword(s):  
Failure Modes ◽  
Fatigue Behavior ◽  
Drill String ◽  
American Petroleum Institute ◽  
Directional Drilling ◽  
Fatigue Wear ◽  
Threaded Connections ◽  
Current Design ◽  
Drilling Operations ◽  
Drill Pipes

Fatigue failures during offshore drilling operations is still a very costly problem. The fatigue behavior of drill pipes is reviewed, and typical failure modes are identified. The effects of drill string curvature during directional drilling on pipe body stress and on the fatigue life is examined. Effects on applied mean stress from drill string weight are discussed. Interaction effects of degradation mechanisms such as fatigue, wear and corrosion are evaluated. Experimental background data and statistical evaluation that form the basis for the current design practice issued by American Petroleum Institute (API) and other guidance in codes and standards is reviewed. Results from several recent testing programs performed under rotating bending of pipes with threaded connections, and tests involving the pipe body under resonance conditions are presented. The tests were made with pipe sizes from 2 7/8 in. to 5 7/8 in. in Grade S-135 pipes. The results are compared with published test data and design guidance such as API Recommended Practice G7 [1]. Recommendations are given for research and testing to improve reliability and the safe operation of drill strings.

Influence of Corrosive Environment on Changes of the ZnAl40Cu3 Upper Alloy Layer

2013 ◽  
Vol 336 ◽  
pp. 103-109
Author(s):  
Rafał Michalik
Keyword(s):  
Surface Layer ◽  
Tribological Properties ◽  
Alloy Layer ◽  
Al Alloys ◽  
Corrosive Environment ◽  
Structural Examination ◽  
Unmodified Alloy ◽  
X Ray ◽  
Cu Alloys ◽  
Corrosive Environments

Zn-Al alloys are used mainly because of their tribological properties as a material alternative to bronze, cast iron and aluminum alloys in bearings, and as a structural material. Improved properties of Zn-Al alloys can be obtained by the addition of copper , silicon and using of heat treatment. Tribological properties of alloys of the Zn-Al-Cu alloys, their structure has been well described in the literature. Far less are, however, studies on the effect of corrosive environments on the structure of the surface layer of the alloy. The purpose of this examination was to determine the effect of corrosive environment on the surface layer of the ZnAl22Cu3 alloy. Subject of examination was the unmodified alloy containing 40% Al mass. and 3%. Cu (Zn - remain). The tested alloy was subject of the following operations: soaking at the temperature of 185°C during 10 hours with cooling in water, soaking at the temperature of 380°C during 10 hours with cooling in water and soaking at the temperature of 380°C w during10 hours with subsequent soaking at the temperature of 170°C with cooling in water. Subject of tests structural examination were samples after potentiostatic tests carried out at potential E = 300 mV Ekor in 24 hours in an acid rain, pH = 3.5. In order to determine the microstructure of the examined coatings metallographic examinations were performed using optical and scanning microscope cooperating with EDS X-ray spectrometer. Quantitative analysis of the selected characteristic microareas determined from X-ray spectral analysis EDX.

scholarly journals Investigation of Stress Concentration and Casing Strength Degradation Caused by Corrosion Pits

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Yan ◽  
Yun Xu ◽  
Yi Zhou ◽  
Kongyang Wang
Keyword(s):  
Stress Concentration ◽  
Pitting Corrosion ◽  
Strength Degradation ◽  
Corrosive Environment ◽  
Collapse Load ◽  
Mechanical Loads ◽  
Inner Surface ◽  
Casing Strength ◽  
Concentration Degree ◽  
Corrosion Pits

Downhole casing and tubing are subjected to corrosion in many cases because of the exposure to corrosive environment. A more serious problem is that pitting corrosion occurs in the casing inner surface. Meanwhile, downhole strings are subjected to various forms of mechanical loads, for example, internal pressure load, external collapse load, or both. These loads acting on the corrosion pits will cause stress concentration and degrade the casing strength. Thus, it is essential to evaluate the stress concentration degree reasonably. The SCF (stress concentration factor) is usually used to characterize the degree of stress concentration induced by corrosion pits. This paper presented a comparison on the SCFs regarding the analytical method for a single pit and experimental method for double pits. The results show that the SCF of a single pit depends mainly on the depth of the corrosion pit; however, the SCF of the double pits strongly depends on the pits distance. A correction factor of 1.3 was recommended in the double pits SCF prediction model.

Research on the Mechanism of Fatigue Crack Initiation of X60 Pipeline Steel after Per-Tension Deformation

2012 ◽  
Vol 197 ◽  
pp. 798-801
Author(s):  
Yu Rong Jiang ◽  
Mei Bao Chen
Keyword(s):  
Fatigue Crack ◽  
Cyclic Loading ◽  
Brittle Fracture ◽  
Crack Initiation ◽  
Pipeline Steel ◽  
Fatigue Cracks ◽  
Fatigue Crack Initiation ◽  
Fracture Characteristics ◽  
Metallic Inclusions ◽  
The Matrix

It is impossible to keep pipelines free from defects in the manufacturing, installation and servicing processes. In this paper, pre-tension deformation of X60 pipeline steel was employed to experimentally simulate the influence of dents and the mechanism of fatigue crack initiation of X60 pipeline steel after per-tension deformation under cyclic loading were investigated. The results indicate that the mechanism of fatigue crack initiation is the typical cleavage fracture characteristics and the cracks mainly initiates from the non-metallic inclusions which was the local brittle fracture materials such as MnS inclusion. With the pre-tension deformation increase, the yield strength of the matrix was increased and the toughness decreased due to the work-hardening effect. With the effects of the non-metallic inclusions larger, the fatigue cracks initiated from the non-metallic inclusions easier.

Three-Dimensional Force and Deflection Analysis of a Variable Cross Section Drill String

1977 ◽  
Vol 99 (2) ◽  
pp. 367-373 ◽  
Author(s):  
B. H. Walker ◽  
M. B. Friedman
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Cross Section ◽  
Three Dimensional ◽  
Variable Cross Section ◽  
Drill String ◽  
Oil Field ◽  
Variable Cross ◽  
Deflection Curve ◽  
Deflection Analysis

A mathematical model of an oil field drill string which includes the effect of torque has been developed. The drill string can include arbitrary members with known mechanical properties. The solution gives the three-dimensional deflection curve, forces on the borehole wall, the magnitude and direction of the resultant force and slope of the deflection curve at the bit.

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