scholarly journals Development of the drilling mud composition for directional wellbore drilling considering rheological parameters of the fluid

2020 ◽  
Vol 244 ◽  
pp. 454-461
Author(s):  
Nadezhda Ulyasheva ◽  
Ekaterina Leusheva ◽  
Ramil Galishin
Keyword(s):  
Molecular Weight ◽  
Shear Stress ◽  
High Molecular Weight ◽  
Oil Field ◽  
Rheological Parameters ◽  
Dynamic Shear ◽  
Drilling Mud ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Drilling Muds

Article presents investigations on the development of a drilling mud composition for directional wells in an oil field located in the Republic of Tatarstan (Russia). Various rheological models of fluid flow and their applicability for drilling muds are analyzed. Laboratory experiments to measure the main rheological parameters of a solution, such as plastic viscosity, dynamic shear stress, as well as indicators of non-linearity and consistency are presented. On the basis of laboratory investigations, it was concluded that high molecular weight polymer reagents (for example, xanthan gum) can give tangible pseudoplastic properties to the washing fluid, and their combination with a linear high molecular weight polymer (for example, polyacrylamide) reduces the value of dynamic shear stress. Thus, when selecting polymer reagents for treating drilling muds at directional drilling, it is necessary to take into account their structure, molecular weight and properties. Combination of different types of reagents in the composition of the drilling mud can lead to a synergistic effect and increase the efficiency of the drilling process as a whole.

scholarly journals Influence of Polymer Reagents in the Drilling Fluids on the Efficiency of Deviated and Horizontal Wells Drilling

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4704
Author(s):  
Tianle Liu ◽  
Ekaterina Leusheva ◽  
Valentin Morenov ◽  
Lixia Li ◽  
Guosheng Jiang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Stress ◽  
High Molecular Weight ◽  
Drilling Fluid ◽  
Horizontal Wells ◽  
Rheological Parameters ◽  
Drilling Fluids ◽  
Dynamic Shear ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer

Improving the efficiency of well drilling process in a reservoir is directly related to subsequent well flow rates. Drilling of deviated and horizontal wells is often accompanied by an increase in pressure losses due to flow resistance caused by small size of the annular space. An important role in such conditions is played by the quality of borehole cleaning and transport capacity of drilling fluid, which is directly related to the rheological parameters of the drilling fluid. The main viscosifiers in modern drilling fluids are polymer reagents. They can be of various origin and structure, which determines their features. This work presents investigations that assess the effect of various polymers on the rheological parameters of drilling fluids. Obtained data are evaluated taking into account the main rheological models of fluid flow. However, process of fluid motion during drilling cannot be described by only one flow model. Paper shows experimentally obtained data of such indicators as plastic viscosity, dynamic shear stress, non-linearity index and consistency coefficient. Study has shown that high molecular weight polymer reagents (e.g., xanthan gum) can give drilling fluid more pronounced pseudoplastic properties, and combining them with a linear high molecular weight polymer (e.g., polyacrylamide) can reduce the value of the dynamic shear stress. Results of the work show the necessity of using combinations of different types of polymer reagents, which can lead to a synergetic effect. In addition to assessing the effect of various polymer reagents, the paper presents study on the development of a drilling fluid composition for specific conditions of an oil field.

Intrinsic viscoelasticity in thin high-molecular-weight polymer films

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
Xiaoyuan Sheng ◽  
Frédéric Wintzenrieth ◽  
Katherine R. Thomas ◽  
Ullrich Steiner
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polymer Films ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer

Structural studies of the capsular polysaccharide from Haemophilus pleuropneumoniae serotype 2

1987 ◽  
Vol 65 (5) ◽  
pp. 414-422 ◽  
Author(s):  
Eleonora Altman ◽  
Jean-Robert Brisson ◽  
Malcolm B. Perry
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Molecular Weight ◽  
Capsular Polysaccharide ◽  
Structural Studies ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Structure Formula ◽  
Nuclear Magnetic

The capsular polysaccharide of Haemophilus pleuropneumoniae serotype 2 (ATCC 27089) is composed of D-glucose (two parts), D-galactose (one part), glycerol (one part), and phosphate (one part). Hydrolysis, dephosphorylation, methylation, enzymic studies, and 1H and 13C nuclear magnetic resonance experiments showed that the polysaccharide is a high molecular weight polymer of a tetrasaccharide repeating units, linked by monophosphate diester and having the following structure:[Formula: see text]

scholarly journals Antigen valence determines the binding of nominal antigen to cytolytic T cell clones.

1985 ◽  
Vol 162 (2) ◽  
pp. 768-773 ◽  
Author(s):  
R F Siliciano ◽  
R M Colello ◽  
A D Keegan ◽  
R Z Dintzis ◽  
H M Dintzis ◽  
...  
Keyword(s):  
Molecular Weight ◽  
T Cell ◽  
High Molecular Weight ◽  
Cytotoxic T Cell ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
T Cell Clones ◽  
Cell Clones ◽  
Nominal Antigen ◽  
Epitope Density

We have shown that cytotoxic T cell clones specific for the nominal antigen FL will bind high molecular weight (600,000 to 2,000,000) polyacrylamide and Ficoll polymers conjugated with 200-600 FL groups per molecule. Low molecular weight polymers (40,000) with the same epitope density did not give stable binding. A high molecular weight polymer with a lower epitope density also failed to bind. Taken together, these results suggest that a substantial degree of multivalence is a necessary factor in the stable binding of nominal antigen to T cell clones.

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