Drill String Vibration Attenuation and Its Effect on a Surface Oscillator Drilling System

1965 ◽  
Vol 87 (2) ◽  
pp. 110-114 ◽  
Author(s):  
F. A. Angona
Keyword(s):  
Fourier Analysis ◽  
Drill String ◽  
Acoustic Vibrations ◽  
String Vibration ◽  
Vibration Attenuation ◽  
Vibratory Motion ◽  
Drilling String ◽  
Drilling System ◽  
Relationship Of ◽  
The Relationship

The attenuation of acoustic vibrations was determined by measuring the decay of stress pulses induced in a drilling string. The relationship of attenuation to frequency was obtained by a Fourier analysis of the pulse after it had traveled various distances in the drill string. The attenuation coefficient was found to be sufficiently low to warrant consideration of drilling methods in which vibratory motion is transmitted from a surface vibrator to the bit by the drill string.

Vibration Analysis of Flexible Multi-Body Drill String System by FSI

2012 ◽  
Vol 184-185 ◽  
pp. 631-640
Author(s):  
Gui Jie Yu ◽  
Lei Fu ◽  
Wen Sheng Xiao ◽  
You Cai Yin
Keyword(s):  
Elastic Vibration ◽  
Drill String ◽  
Lateral Vibration ◽  
Drilling String ◽  
Structure Vibration ◽  
Drilling System ◽  
Drill Pipes ◽  
Multi Body ◽  
The Relationship ◽  
Vertical Borehole

Combined with features of flexible multi-body drilling string system and top-drive drilling system, the characteristic equation for lateral, twisting and longitudinal coupled vibration of flexible multi-body drilling string system is developed based on elastic vibration theory and finite element method, and the lateral vibration constraints is restored. Within 1700m vertical borehole, the relationship between the intrinsic frequency of flexible multi-body drilling string system and axial load, static drilling pressure, mud, length of drill collars, length of drill pipes are gained by analyzing the lateral vibration, twisting vibration and longitudinal fluid-structure vibration of flexible multi-body drilling string system by using software ANSYS. One to five step intrinsic frequencies of flexible multi-body drilling string system are gained. The research is about the theoretical basis for Well bore control theory of top drive drilling.

scholarly journals Development and Application of the Downhole Drilling String Shock-Absorption and Hydraulic Supercharging Device

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yongwang Liu ◽  
Zhichuan Guan ◽  
Hongning Zhang ◽  
Bo Zhang
Keyword(s):  
Longitudinal Vibration ◽  
Rock Breaking ◽  
Drill String ◽  
Field Application ◽  
Drilling Speed ◽  
Technical Design ◽  
Fundamental Study ◽  
String Vibration ◽  
Drilling String ◽  
Breaking Energy

It is a hot topic for deep/ultradeep wells to improve rock-breaking efficiency and drilling speed by available downhole energy. Based on different downhole energies and working conditions, specialized plunger pump is proposed to convert longitudinal vibration of drilling string into rock-breaking energy. Technical design is developed to generate high-pressure water jet. And then a simulation model is built to verify feasibility of the technical design. Through simulation, the influence law of key factors is obtained. On this basis, this device is tested in several wells. The result indicates this device can increase drilling speed as much as 136%. Meanwhile the harmful vibration can be absorbed. The energy from drilling string vibration is of high frequency and increases as well depth and formation anisotropy increase. By reducing adverse vibration, this device is able to increase the drilling speed and the service life also meets the demand of field application. The longest working time lasts for more than 130 hours. The performance of this device demonstrates great application prospect in deep/ultradeep resources exploration. To provide more equipment support for deep/ultradeep wells, more effort should be put into fundamental study on downhole drill string vibration and related equipment.

Drilling String Vibration: Modelling and Simulation

2018 ◽  
Author(s):  
Sergio Amat ◽  
Gustavo E. Henríquez Velez ◽  
María J. Legaz
Keyword(s):  
Global Economy ◽  
Drill String ◽  
Optimal Parameters ◽  
Offshore Structure ◽  
String Vibration ◽  
Drilling Performance ◽  
Drilling String ◽  
Drilling Operations ◽  
Offshore Industry ◽  
Crucial Part

The offshore industry has a significant impact on the global economy and it is expected to grow over the next 4 years. A crucial part of an offshore structure is the drill string. Drill strings can be seriously damaged by vibration during drilling operations. The control of vibrations in drill strings is essential. In drilling wells, this is useful to minimize the risks of well loss and also to improve drilling performance. The objective of this study is to model and simulate the vibrations in drill strings. This is made to know the region of stabilization of the system and to establish the optimal parameters of drilling which can be manipulated from the driller console, such as angular velocity of the drill string on the surface and the weight on the drill bit. The simulation of these vibrations is made by solving the differential equations that describe these phenomena. An interface for the manipulation of variables involved in the models of the drill string has been designed and shown in this work.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

Severe Paradoxical Dysphonia in Two Young Women

1993 ◽  
Vol 2 (3) ◽  
pp. 52-55 ◽  
Author(s):  
Michael Collins ◽  
Robert McDonald ◽  
Robert Stanley ◽  
Timothy Donovan ◽  
C. Frank Bonebrake
Keyword(s):  
Young Women ◽  
Theoretical Basis ◽  
Therapeutic Regimen ◽  
Instrumental Data ◽  
Relationship Of ◽  
The Relationship

This report describes an unusual and persistent dysphonia in two young women who had taken a therapeutic regimen of isotretinoin for intractable acne. We report perceptual and instrumental data for their dysphonia, and pose a theoretical basis for the relationship of dysphonia to this drug. We also provide recommendations for reducing the risk of acquiring a dysphonia during the course of treatment with isotretinoin.

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