With rapidly growing global demand for energy resources, oil and gas exploration & production companies face mounting pressure to maximize supply and increase the rate of discovery for new energy sources. Increasingly operating in more remote locations and investing heavily in equipment and facilities, companies face greater financial and operational risks than ever before. Optimization of dril...

RATIONALE Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochond...

This paper presents a time-varying sliding mode adaptive controller in order to handle the stick-slip oscillation of nonlinear rotary drilling system. The time-varying sliding mode controller with strong robust has two time-varying sliding surfaces, one of them induced time-varying integral sliding mode control can control the transient stage of the rotary drilling system and ensure the system ...

The fiber reinforced plastics (FRPs) are being used widely in the most diverse applications ranging from the aerospace to the sports goods industry. Drilling in particular is important to facilitate the assembly operations of structurally intricate composite products. The drilling of holes in FRPs leads to drilling induced damage which is an important research area. The researchers worldwide ha...

Drilling engineering is not only a systematic engineering that involves several workcategories, work procedures,intersectant and continuous operation, but also is a concealed underground engineering. There are uncertain factors in drilling projects, which have the characteristics of high investment and risk. On the basis of the overall analysis of the two factors of geology and engineering, the...

In this paper, the dynamic response of resonating nano-beams is investigated using a strain gradient elasticity theory. A nonlinear model is obtained based on the Galerkin decomposition method to find the dynamic response of the investigated beam around its statically deflected position. The mid-plane stretching, axial residual stress and nonlinear interaction due to the electrostatic force on ...

The Measurement/Logging While Drilling (M/LWD) system is a kind of sensors system which is used to help oil/gas drilling field technicians to steer well drilling. In M/LWD, several kinds of sensors are installed into drill string to measure the underground logging data during well drilling operations, and a sink within the drill string collects the logging data from the sensors and then transmi...

Recently, the economic feasibility of drilling a horizontal well improved drastically due to advances in drilling technology. Advantages of horizontal wells over vertical well applications have been confirmed by many scientists(1-4) and operators(5-7). Horizontal wells showed many distinct advantages over vertical ones such as improvement of well productivity, attenuation of sand production, an...

We show that crude oil production from existing wells in Texas does not respond to current or expected future oil prices, contradicting a basic prediction of Hotelling’s (1931) canonical model of exhaustible resource extraction. In contrast, the drilling of new wells exhibits a strong price response, as does the rental rate on drilling rigs. To explain these observations, we reformulate Hotelli...

The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties...