Wiertnictwo, Nafta, Gaz
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ISSN 1997-2011
e-ISSN: 2300-7044
Issue Date
2006
Volume
T. 23
Number
Nr 1
Description
Journal Volume
Wiertnictwo, Nafta, Gaz
T. 23 (2006)
Projects
Pages
Articles
Friction pressure loss determination of yield power law fluid in eccentric annular laminar flow
(2006) Ahmed, Ramdan; Miska, Stefan; Miska, Włodzimierz
Accurate predictions of friction pressure losses are very important in drilling and well completions operations. In some applications, for example, drilling in areas where the margin between pore pressure and fracture pressure gradients is small, inaccurate predictions of bore hole pressure may lead to serious complications and even a loss of the well. This paper is focused on a flow of yield power law type (pseudo-plastic with the yield stress) fluid in the annular space with the possibility that the inner pipe maybe eccentric. A new mathematical model that is based on a concept of generalized average wall shear rate - wall shear stress relationship is presented. A carefully designed laboratory facility that permits accurate differential pressure measurements as a function of flow rate in both pipe and annular flow has been developed. The desired rheology of the fluids was obtained by mixing two types of polymers (PAC and HEC) with water. Pipe flow measurements have been utilized to produce flow curves and subsequently the fluid rheological characterization (yield stress, consistency index and flow behavior index). The results of measured pressure losses are compared to those predicted by the proposed model. While the discrepancies are noticeable the difference is less than 15% and frequently is even less than 5%. We believe that the proposed model is simple useful for practical design applications.
Sprawność eksploatacyjna samonośnych rurociągów pionowych do odmetanowania pokładów węgla
(2006) Artymiuk, Jan
Coalbed methane can be found in the Upper Silesian Coal Basin. In the Lower Silesian Coal Basin the methane resources are smaller, and in the Lublin Coal basin no significant methane concentrations have been documented so far. Recently, a successful technology of methane removal has been elaborated, which is treated as gas recovery from unconventional sources. Almost 16 mln PLN was spent on a methane removal system implemented in the coal mine 'BUDRYK', consisting of two vertical self-supporting pipelines connected with motors and electrical energy generators. This is the most advanced installment in the Polish mining industry, thanks to which the cost can be lowered and the gas, source of numerous catastrophes, used economically. The continuity of supplies to the surface systems depends on the efficiency of pipelines suspended in the mine's shaft, through which methane it transmitted to the nearby gas power and heat plant. Their control is one of the basic exploitation issues to be solved, especially in the conditions of hindered direct access. Additional obstacle is the strength sensor, which may disconnect a well working gas pipeline. The calculation and research methods enabling safe operation of the pipelines are presented in the paper.
New combined drilling, workover and snubbing rig concept
(2006) Artymiuk, Jan; Zachariasen, Erik
Today's workover and service operations require multi-functional ability to let operators select the best way to perform the well operation. By introducing a new land rig concept based on a patented rack & pinion drive system a new generation of rigs can instantly switch between workover, drilling and snubbing operations. The new rig concept has direct drive thus no drill line. Mobilization time is reduced as the rig has fewer truck loads, faster rig up and a higher automation level. One land rig currently under construction will be the world's first single operator unit, with full pipe handling capability and fully automated control system. The rig is fully equipped with 250 T top drive which can be used for rotation and snubbing, purpose designed snubbing slips and other features supporting multifunctional well operations. The paper will focus on features related to the land rig under construction, and how it may reduce operational cost and improve well performance.
Problemy eksploatacyjne agregatów cementacyjnych w operacjach o zwiększonym ryzyku
(2006) Bednarz, Stanisław; Bochenek, Kazimierz; Serafin, Robert
Cementing of drilling wells in some conditions may encounter difficulties related with the behaviour of the cement aggregate, e.g. injection of cement slurry when packer has to be introduced to the annular space, injection of foam solutions, sealing up to prevent the migration of gas through the sealing cover, injection of solutions with microspheres. Owing to the progressive and turning motion, hydraulic vibrations are observed during the cement plunger pump operation. They intensify when an aerated slurry is injected, e.g. air adsorbed by microspheres, gas bubbles in foamy cement or having high density/viscosity (at high rates of the plunger). Other operations sensitive to hydraulic vibrations are cementing of shallow gas horizons, especially in clayey intervals prone to shrinking after a contact with the cement filtrate. The recirculation of the slurry to degas the aggregate hinders fluent application of the cementing procedure. Possibilities of limiting exploitation difficulties of aggregate operation to cementing operations are presented in the paper.
Drgania maszyn roboczych urządzeń wiertniczych a bezpieczeństwo pracy
(2006) Bednarz, Stanisław; Urba, Roman
Vibrations cause hazardous effects in mechanical systems of machines. They may result in misoperation of the machines and their working parts, lowering their durability. They also have a negative influence on the crew's health and the environment. Considerable vibrations accompany the process of a well drilling (drilling, hoisting and tripping of the casing, auxiliary works with the main set, e.g. drilling table, head, hoist and pumps). The results of measurements of American, Romanian and Polish drilling rigs are presented in the paper. Drilling rigs should have such a design that hazards related to their use are minimized, mainly at their source.