cylindrical thin-walled tubes due to construction and easy installation, high energy absorption capacity are used in the automotive industry as an impact energy absorber. however, the main weakness of cylindrical tubes is in the high initial peak load. therefore, in this paper, to overcome this weakness, a buckling initiator is used at the top of the tube. this buckling initiator is a steel rod...

Downhole drilling motors or mud motors are frequently used during the oil and gas well construction, especially for construction of directional and horizontal segments. However, low operation life of the down hole drilling motors and high rate of wear in their working elements may constrain their application due to technical and economical disadvantageousness. In this work, a high-torque modula...

An approach to the optimization of drilling tools which is based on the analysis of dependence of drilling cost on the tool shape is presented. The effect of tool shape on the energy consumption in rotatory drilling and on the lifetime of tool is studied analytically. It is shown that the main part of drilling energy is consumed not for the rock removal, but rather by the microfracture, shearin...

Abstract This work investigates the drilling performance by reaming while (RWD) using a dual-body bit and compared it with conventional standard bit. The consisted of 2.45-in. pilot located at short distance ahead 2.47 × 3.97-in. reamer. Conducting series experiments simulation rig full monitoring sensors, we further studied as function between is greatly important parameter affecting mud diffu...

The accurate prediction of wellbore temperature distribution helps to accurately estimate well pressure profile and bottom-hole pressure (BHP) which is important in the under-balanced drilling (UBD) operation. In this paper effect of temperature variation due to heat transfer of drilling fluid with the formation and also oil and gas production from the reservoir into the annulus in under-balanc...

in this paper, the results of surface and ground water quality monitoring during drilling of three deep exploratory wells in geothermal project in north west of sabalan in meshkinshahr are analyzed. the region has been investigated by various researchers to generate electricity using geothermal energy. drilling in deep geothermal projects, a variety of materials such as cement, bentonite, barit...

In this paper, non parametric Data Envelopment Analysis (DEA) was subjected to the energy data of wheat producers in Punjab state, India, and technical, pure technical and scale efficiencies were calculated for farms both category wise and zone wise. The main objective was to determine the strength of the correlation between non-parametric efficiencies and indices such as energy ratio and speci...

Objective. This study aimed to evaluate effects of type 1 diabetes mellitus and mini-implant placement method on the primary stability of mini-implants by comparing mechanical stability and microstructural/histological differences. Methods. After 4 weeks of diabetic induction, 48 mini-implants (24 self-tapping and 24 self-drilling implants) were placed on the tibia of 6 diabetic and 6 normal ra...

High power carbon dioxide lasers have successfully been used in drilling or cutting ngineering materials such as metals, polymers and ceramics over the years. Can a arbon dioxide laser be used to efficiently drill different rocks in a deep gas well? esearch sponsored by US Department of Energy has been carried out to answer this uestion. This paper will report the study results of using a super...