The low-frequency tube wave speed is given explicitly for a variety of borehole nvironments. The presence of a logging tool, the effects of casing, and bore eccentricity are considered. The results are all relatively simple and indicate that the speed ecreases in the presence of a tool or borehole ccentricity. The speed increases in the presence of casing as long as the casing shear modulus exc...

The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burs...

Calocybe indica, a tropical edible mushroom, is popular because it has good nutritive value and it can be cultivated commercially. The current investigation was undertaken to determine a suitable substrate and the appropriate thickness of casing materials for the cultivation of C. indica. Optimum mycelial growth was observed in coconut coir substrate. Primordia initiation with the different sub...

A polygon motor consists of several mirror faces and it is one of the core components for a laser beam printer and a copier. Under high-speed rotation, aeroacoustic noise with a peak frequency of rotational speed times the number of mirror faces and its harmonics is prominently generated from a polygon motor covered with a casing. This paper describes a method to predict such noise that is gene...

ABSTRACT- Almost all oyster mushroom producers in Iran produce this kind of mushroom without any kind of casing soil. Although different kinds of casing soils are available for Agaricus bisporus, limited information is available regarding Pleurotus ostreatus. Availability of peat in many regions around the world is a concern and some researchers' efforts have been devoted to a search for altern...

Brookhaven National Laboratory was requested to conduct a literature survey for the best available cement to use in the proposed casing patch as part of the Geothermal Drilling Organization (GDO) project on remediation of deformed casings. A total of 50 wells has been identified with deformed production casing in Unocal’s portion of The Geysers geothermal field. Reduced internal diameter and ca...

When the thermal stresses induced in a geothermal well’s casing string exceed the yield strength of the casing material, the fatigue behavior of the latter can be defined as low cycle fatigue (LCF). The connection threads in the casing body amplify the local stress distribution and lower LCF resistance. A theoretical approach is presented to evaluate LCF resistance and compared with preliminary...

This paper analyzed the characteristics of managed pressure drilling (MPD) technology and impact of wellhead back pressure on the wellbore annulus pressure profile, and found that the application of this technology provides room for improvement to the current casing program design. Meanwhile, the equivalent density of drilling fluid in wellbore annulus needs to consider the impact of back press...

SUMMARY Detailed measurements have been made of the casing boundary layer flow before and after the nozzle blades of a single stage model air turbine. The measurements were made with the natural casing inlet boundary layer and two artificially thickened boundary layers. The results differ considerably from those usually obtained in two dimensional cascades. There was no sign of the usual second...

This research paper presents numerical studies of the characteristics of warhead fragmentation in terms of initial velocities, spray angles of fragments and fragment mass distribution of high explosive (HE) warhead. The behavior of warhead fragmentation depends on shape and size of warhead, thickness of casing, type of explosive, number and position of detonator, and etc. This paper focuses on ...