Impact of Viscoelastic Characteristics of Oil Based Muds/Synthetic Based Muds on Cuttings Settling Velocities

2017 ◽  
Author(s):  
M. C. Altindal ◽  
E. Ozbayoglu ◽  
S. Miska ◽  
M. Yu ◽  
N. Takach ◽  
...  
Keyword(s):  
Aging Time ◽  
Viscoelastic Properties ◽  
Settling Velocity ◽  
Drilling Fluid ◽  
Time Dependent ◽  
Drilling Fluids ◽  
Structure Development ◽  
Gel Structure ◽  
Fluid Characterization ◽  
Fluid Characteristics

Inaccurate calculation of settling and slip velocities of cuttings leads to inaccurate determination of cuttings concentration and, hence, borehole pressure, as well as inaccurate lag times. To minimize these problems, an understanding of the relation between drilling fluid characteristics and the cuttings transport process is essential. It is desirable for drilling fluids to form a gel structure to help cuttings transportation and suspension of solids. The gel structure development is proportional to increase in aging time. The increase in aging time yields higher shear stress responses at a constant rate of deformation to the drilling fluid sample. The gel structure development helps keep cuttings in suspension and shows a viscoelastic response to small deformations. Understanding these viscoelastic responses is important in rheological characterization and settling velocity prediction. Thus, viscoelastic drilling fluid characteristics should be investigated in depth to better estimate settling and slip velocities of cuttings and to increase cutting transport efficiency. The main focus of this project is to work on viscoelastic and time-dependent fluid characterization to identify the relation between rheological properties and settling velocities of cuttings. Rheological experiments were conducted using an Anton Paar Physica MCR 301 Rheometer. Three different drilling fluids, Water Based Mud (WBM), Oil Based Mud (OBM) and Synthetic Based Mud (SBM), are used for rheological and settling velocity experiments. Stress Overshoot Tests (SOTs) and Steady-Shear experiments were performed to investigate viscoelastic properties and gel structure of the fluids, and to examine time and temperature dependence of WBM, OBM and SBM. Information obtained from the viscoelastic and time-dependent fluid characterization tests was coupled with settling velocity data using both arbitrary shape of cuttings and spherical particles. A mathematical model that considers viscoelastic properties and time dependency of drilling fluids was developed to estimate settling and slip velocities of the cuttings. Comparisons between the proposed models and existing models based on standard rheological measurements were also done. The results show that the proposed model has good agreement with the experimental data.

Viscoelasticity and Drilling Fluid Performance

2014 ◽  
Author(s):  
John Lee ◽  
Ahmadi Tehrani ◽  
Steve Young ◽  
Christine Nguyen
Keyword(s):  
Steady State ◽  
Viscoelastic Properties ◽  
Xanthan Gum ◽  
Drilling Fluid ◽  
Polymer Concentration ◽  
Shear Thinning ◽  
Drilling Fluids ◽  
Fluid Viscosity ◽  
Field Equipment ◽  
The Impact

Viscoelastic properties of drilling fluids are not often measured due to a lack of understanding of their impact on fluid performance as well as a lack of field equipment suitable for such measurements. A study has been conducted recently to evaluate the viscoelastic properties of xanthan gum and invert drilling fluids and their impact on barite suspension quality and rheology. Both a Brookfield YR-1 rheometer and a Bohlin Gemini 150 rheometer were used to generate data for comparison. The impact of viscoelasticity on steady-state rheology, thixotropy and shear thinning was evaluated using a multi-speed rheometer. A soon-to-be-adopted API recommended procedure was used to measure the barite sag tendency under dynamic conditions. Aqueous solutions of xanthan gum showed that viscoelasticity, shear thinning and thixotropy increased with increasing polymer concentration. When the solutions were weighed up with barite, they became more viscoelastic, slightly more thixotropic, but less shear thinning. Proper suspension of barite was observed at a xanthan gum concentration of 2 lb/bbl without any other additives. Compared to xanthan-barite suspensions, invert drilling fluids of similar density exhibited a greater viscoelasticity but less thixotropy and shear thinning. Treatment of invert drilling fluids with viscoelastic polymers resulted in a further enhancement of viscoelasticity and thixotropy, but a slight deterioration in shear thinning. Barite suspension quality showed a certain degree of correlation with viscoelasticity as well as steady-state rheology; however, these properties were temperature dependent for invert drilling fluids. Hydraulic analyses indicated that viscoelastic additives can impact fluid viscosity thus affecting pressure loss, equivalent circulating density and hole cleaning. Viscoelasticity enhancement may be used to improve barite suspension quality under certain conditions, but its impact on hydraulics must be carefully considered.

Dynamic and Static Sagging Characterization and Performances of Four Oil Based Muds

2016 ◽  
Author(s):  
Mesfin Belayneh ◽  
Bernt S. Aadnøy ◽  
Sharman Thomas
Keyword(s):  
Yield Stress ◽  
Storage Modulus ◽  
Viscoelastic Properties ◽  
Loss Modulus ◽  
Drilling Fluid ◽  
High Viscosity ◽  
Experimental Result ◽  
Drilling Fluids ◽  
Oil Water ◽  
Water Ratio

This paper presents the barite sagging phenomenon of four OBM systems having the same density, but different rheology properties. The investigations of barite sagging is based on dynamic sagging and viscoelasticity testing. The viscoelastic properties related to gel formation of the drilling fluids were investigated under amplitude and frequency sweeps. The study also tries to correlate the results obtained from dynamic sag with the dynamic viscoelastic properties of the drilling fluid and standard API rheology parameters. The results show that as the oil water ratio increases the drilling fluid rheology parameters such as lower shear yield stress (LSYS), yield stress (YS) and plastic viscosity (PV) parameters also increases. In addition, the viscoelastic loss and storage modulus decrease. From the viscoelasticity study, except for 90:10 OWR, it is observed that as the oil water ratio increase, the yield stress and the flow point also increases. The 90:10 OBM shows no viscoelasticity behavior. Comparing the extreme 60:40 and 90:10 OBMs (i.e. as OWR increase), the experimental result shows that the sagging index increases by 9%. The dynamic sagging factor decreases as the ratio of storage modulus to loss modulus increases (i.e. as OWR decrease). Except for high viscosity and hydraulics, the overall analysis of drilling fluids shows that the 60:40 OWR is the better in terms of sagging, filtrate loss and hole cleaning performance.

Viscoelastic properties of a bent and straight dimeric liquid crystal

1993 ◽  
Vol 3 (5) ◽  
pp. 597-602 ◽  
Author(s):  
Gregory A. DiLisi ◽  
E. M. Terentjev ◽  
Anselm C. Griffin ◽  
Charles Rosenblatt
Keyword(s):  
Liquid Crystal ◽  
Viscoelastic Properties

The influence of osteopathic correction on the viscoelastic characteristics of the lower leg muscles

2019 ◽  
pp. 93-98
Author(s):  
E. M. Timanin ◽  
N. S. Sydneva ◽  
A. A. Zakharova
Keyword(s):  
Viscoelastic Properties ◽  
Gastrocnemius Muscle ◽  
Soft Tissues ◽  
Subjective Assessment ◽  
Lymphatic Drainage ◽  
Intercellular Substance ◽  
Leg Muscles ◽  
Before And After ◽  
Viscoelastic Characteristics ◽  
Instrumental Methods

Introduction. To date there is a lack of studies dedicated to the objectification of the palpation data obtained by a specialist during the osteopathic examination. The issue of the evidence of the results of osteopathic correction still remains important. Search for instrumental methods allowing to register and to measure various palpation phenomena and manifestations of somatic dysfunctions is very relevant for the development of osteopathy as a science. It is also very important to find objective characteristics of these methods.Goal of research — to study viscoelastic characteristics of the soft tissues of the lower legs by palpation and instrumental methods before and after osteopathic correction.Materials and methods. 22 volunteers (12 women and 10 men) aged 18–23 years without complaints of the musculoskeletal system were examined. Osteopathic diagnostics and measurement of the viscoelastic properties of muscles were carried out by the method of vibration viscoelastometry before and after osteopathic correction.Results. Correlation analysis by Spearman showed that the subjective assessment of an osteopath positively correlated with both elasticity (r=0,43, p<0,05) and viscosity of soft issues (r=0,29, p<0,05). For the gastrocnemius muscle, this pattern was even more pronounced — for elasticity r=0,51, p<0,05, for viscosity =0,34, p<0,05. After osteopathic correction no changes in the elasticity of the soft tissues were observed. The viscosity of the tissues reduced, but in the projection of the gastrocnemius muscle, these changes were not statistically significant (p=0,12), whereas in the projection of the soleus muscle statistically significant changes (p=0,034) were observed.Conclusion. Changes in the viscoelastic properties of tissues demonstrated that the effects of osteopathic correction with the use of myofascial mobilization techniques, articulation mobilization techniques, and lymphatic drainage techniques were not obvious. The elasticity of soft tissues of the lower legs did not change, while the viscosity decreased, especially in the projection of the soleus muscles. This effect of the osteopathic correction can be associated with the effect of thixotropy — the transformation of gel-like intercellular substance into sol. Thus, the research showed that vibration viscoelastometry can be used for the objectifi cation of the condition of soft tissues and of the effects of osteopathic correction.

Viscoelastic Properties of Polysaccharides Derived from the Fungal Modification of Native Starch

2010 ◽  
Vol 1 (2) ◽  
pp. 56
Author(s):  
Arturo Rodriguez ◽  
Mohini M. Sain ◽  
Robert Jeng ◽  
Alexis Baltazar y Jimenez
Keyword(s):  
Viscoelastic Properties ◽  
Native Starch
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