Browsing by Subject "rheological models"

Now showing 1 - 5 of 5

Access status: Open Access ,
Numerical simulation of drilling fluid flow in annular the space of the borehole
(2015) Kowalska-Kubsik, Iwona
This paper presents the numerical results of a numerical analys is of drilling fluid flow through annular space in the borehole. The analysis used the Herschel–Bulkley rheological fluid model. The obtained results of the analysis for three cases with variable geometry. Variable geometry is associated with a larger diameter drill in the joints of drill pipes, and consequently, with reduced flow cross-section. A comparison of pressure values at the end of the analyzed examples showed that in the example of a simple drill pipe with out joints, pressure values were 30% higher than in the case, which takes into account changes in the geometry of the joints.
Access status: Open Access ,
The influence of anti-sedimentation agents on the technological parameters of cement slurry
(Wydawnictwa AGH, 2017) Kremieniewski, Marcin; Rzepka, Marcin; Stryczek, Stanisław; Wiśniowski, Rafał
Recently, the intensifying development of shale drilling has contributed to the more numerous realization of directional and horizontal boreholes. Moreover, such boreholes are more advantageous as they provide about 4 times higher production than in their vertical counterparts, give access to poorly drained areas, or production of already developed reservoir, where only a new borehole has to be introduced to the network. It should be stressed that the sealing of the casing columns is a challenge because of the restrictions set before drilling fluids used for sealing horizontal boreholes. Slurries play a special role while sealing horizontal boreholes and therefore their technological parameters and density should be adjusted to the geological-reservoir conditions. At the stage of designing slurries for sealing horizontal boreholes, the most important parameters are: sedimentation stability, zero water settling water settling and low filtration. Meeting these requirements was possible by selecting proper admixtures and additives, which in turn, is a guarantee of the uniform and homogeneous structure of fresh and hardened cement slurry. Thus formed cement sheath of bounded slurry should be impervious to gas and have good mechanical properties over the length of the sealing without any trends of anisotropy of the medium in particular points. Modification and designing specialist recipes for definite technological conditions lie, among others, in choosing proper slurry additives and admixtures. However, obtaining appropriate parameters for given conditions may be connected with a change of other parameters deciding about the efficiency of the sealing of a given horizon. Therefore while working out a new recipe for a slurry, the designer should account for the analytical results and influence of the applied agents on all of the parameters of slurry. This is the subject matter of the paper.
Access status: Open Access ,
The influence of ash from fluidized-bed combustion of lignite on rheological properties of cement slurries
(2014) Skrzypaszek, Krzysztof; Stryczek, Stanisław; Wiśniowski, Rafał
Cementing jobs are a very important element of drilling technology considering the completion of a given field. The selection of an appropriate recipe for sealing slurry is a challenge for the cementing services and research units. Both fresh and set slurry should meet a number of technological requirements. Various chemical, physical and mechanical properties of the ground and rock mass media to a different degree influence the technological parameters of the injected fluid. The sealing slurries have to meet certain criteria if the high efficiency of works is to be provided. The first of them is the criterion of physicochemical congruence with the environment. The second condition stems from the criterion of pumping the slurry. It is realized by selecting an appropriate rheological model and rheological parameters of the sealing slurry. The third requirement is connected with the need of providing suitable strength and durability of hardened sealing slurries as a result of the physicochemical processes. The fourth condition should account for the economy and ecology factors. The selection of recipes for sealing slurries should not be accidental or an output of unfniished laboratory tests. The correct sealing and reinforcing of the rock mass are prerequisites of further engineering works performed in the wellbore. The results of laboratory experiments on the concentration of ash from the fluidized-bed combustion of lignites on rheological parameters of fresh sealing slurries based on drilling cement class G (HSR) Dyckerhoff (API Class G HSR - Black Label) for various water/cement ratios are presented in this paper.
Access status: Open Access ,
The influence of time of rheological parameters of fresh cement slurries
(2014) Stryczek, Stanisław; Wiśniowski, Rafał; Gonet, Andrzej; Złotkowski, Albert
The rheological properties of sealing slurries are very important at the stage of designing and realization of works related to the sealing and reinforcement of the ground rock mass with the use of drilling technologies. For providing high efficiency of the works related to the sealing of casing pipes in deep wells and the rock mass with borehole injection methods, the rheological parameters of sealing slurries should be selected depending on [1,2]: — reservoir conditions of ground and rocks to be sealed, — geometry of borehole and circulation system, — interactions between the stream of injected slurry and the resulting flow resistance, especially in the sealed medium. The results of laboratory experiments focusing on the influence of time on the rheological parameters of fresh sealing slurries based on API Class G HSR - Black Label drilling cement (Dyckerhoff) for various water to cement ratios are presented in the paper.
Access status: Open Access ,
Wpływ rodzaju cementu na właściwości reologiczne zaczynów uszczelniających stosowanych w technologiach wiertniczych
(2010) Stryczek, Stanisław; Wiśniowski, Rafał; Gonet, Andrzej; Złotkowski, Albert
Right and optimality design hydraulic of flow cement slurry has influence on good grouting drill casing in wellbore. For this purpose is necessary definite rheological parameter cement slurry and checking in rheological fluid model, which best represented characteristic this composition. Type of used cement and quantity water of concrete mix effected on physic-chemical property and command for each case water-cement ratio rheological model and his mathematic parameter. In paper presentation result laboratory studies measurement rheological parameter four popular used cement in technology of drill casing grouting and command for each rheological model and mathematic value for him.