Cleaning Technology on Filter Cake of Silicate-Based Polymer Drilling Fluid

2013 ◽  
Vol 310 ◽  
pp. 107-111 ◽  
Author(s):  
Qin Qin Ye ◽  
Yong Zhang Zhou ◽  
Dong Sheng Chen
Keyword(s):  
Weight Loss ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Minor Role ◽  
Rotating Speed ◽  
Before And After ◽  
Core Permeability ◽  
Flush Fluid ◽  
Cleaning Technology ◽  
A Minor

In order to evaluate the cleaning effect on filter cake, a set of test device was designed. The cleaning fluid formula and parameters which were elected by experiments were optimized. The weight of the filter cake before and after cleaning was analyzed by wet weight method. New alkaline flush fluid formula was confirmed finally and the washing technology suitable for filter cake of silicate-based polymer drilling fluid has been studied out. The effect of core permeability after cleaning has also been evaluated. The experimental results showed that No.5 formula was suitable for the cleaning filter cake of silicate-based drilling fluid filter, and the weight loss rate could reach 94.09% when cleaning time was 60 minutes. The rotating speed played a minor role in cleaning effect. Weight loss rates increased with the increase of temperature. The weight loss reached 100% when temperature was 90°C. The cleaning fluid could inprove the core permeability up to 900.13% after cleaning, which indicated that the cleaning fluid formula had efficient effect on cleaning filter cake of silicate-based polymer drilling fluid.

Renal prostanoids after unclipping the denervated one-kidney, one-clip hypertensive rat

1985 ◽  
Vol 249 (4) ◽  
pp. F542-F545 ◽  
Author(s):  
R. Vandongen ◽  
H. McGowan ◽  
H. Anderson ◽  
A. Barden
Keyword(s):  
Blood Pressure ◽  
Neural Mechanisms ◽  
Renal Nerves ◽  
Minor Role ◽  
Similar Extent ◽  
Before And After ◽  
Blood Pressures ◽  
A Minor ◽  
Prostanoid Synthesis ◽  
Stimulation Of

The contribution of the renal nerves in maintaining blood pressure and modulating renal prostanoid synthesis was examined in established (less than 8 wk in duration) one-kidney, one-clip (1K,1C) hypertension in the rat. Systolic blood pressure was measured for 7 days after renal denervation, at which time the renal artery clip was removed. Twenty-four-hour urinary excretion of PGE2 and 6-keto-PGF1 alpha (stable degradation product of PGI2) was determined before and after denervation and unclipping. Compared with sham-denervated rats, denervation (n = 15) resulted in a small but significant fall in blood pressure (from 216 +/- 4 to 182 +/- 4 mmHg after 48 h) and an increase in urinary 6-keto-PGF1 alpha (from 31 +/- 4 to 43 +/- 5 ng/24 h after 24 h). There was no change in PGE2 excretion. Seven days after surgery, blood pressures were similar in denervated (202 +/- 4 mmHg) and sham-denervated (211 +/- 5 mmHg) rats and fell to a similar extent 24 h after unclipping (142 +/- 3 and 147 +/- 4 mmHg, respectively). Urinary 6-keto-PGF1 alpha increased from 25 +/- 5 to 74 +/- 11 in denervated and 21 +/- 2 to 72 +/- 9 ng/24 h in sham-denervated rats in the 24 h after unclipping. PGE2 excretion increased approximately twofold over this period. These findings indicate that the renal nerves have only a minor role in established hypertension in the 1K,1C rat and that the reversal of hypertension and stimulation of renal prostanoid synthesis following unclipping is not dependent on neural mechanisms.

scholarly journals Formation Damage Avoidance by Reducing Invasion with Sodium Silicate-Modified Water-Based Drilling Fluid

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1485 ◽  
Author(s):  
Salaheldin Elkatatny ◽  
Tural Jafarov ◽  
Abdulaziz Al-Majed ◽  
Mohamed Mahmoud
Keyword(s):  
Rheological Properties ◽  
Sodium Silicate ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Ct Scanner ◽  
Tight Sandstone ◽  
Ct Number ◽  
Mechanical Removal ◽  
Before And After

Drilling multilateral and horizontal wells through tight gas reservoirs is a very difficult task. The drilling fluid should be designed to reduce both fluid and solid invasion into the tight formation to avoid formation damage by aqueous phase trapping. The objective of this paper is to assess the effect of sodium silicate on the drilling fluid properties such as rheological and filtration properties. Rheological properties (RPs) were measured at different temperatures while the filtration test was performed at 300 °F and 300 psi differential pressure. A retained permeability calculation was determined to confirm the prevention of solid invasion. The rheological properties results confirmed that the optimal concentration of sodium silicate (SS) was 0.075 wt.% and at the same time, the temperature has no effect on the SS optimum concentration. Using 0.075 wt.% of SS reduced the filtrate volume by 53% and decreased the filter cake thickness by 65%. After mechanical removal of the filter cake, the return permeability of the tight sandstone core was 100% confirming the prevention of solid invasion. The computer tomography (CT) scanner showed that the CT number before and after the filtration test was very close (almost the same) indicating zero solid invasion and prevention of the formation damage.

scholarly journals Application of Microemulsion Systems in the Formulation of Biodegradable Pre-Flush Fluid for Primary Cementing

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4683
Author(s):  
Elayne A. Araújo ◽  
Thaine T. Caminha ◽  
Evanice M. Paiva ◽  
Raphael R. Silva ◽  
Júlio Cézar O. Freitas ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Xrd Analysis ◽  
Oil Well ◽  
Cement Slurry ◽  
Removal Time ◽  
Primary Cementing ◽  
Flush Fluid ◽  
Cake Removal

Oil well cleanup fluids (pre-flushes) are intermediate fluids pumped ahead of the cement slurry; they are able to clean the well walls by removing the filter cake formed by the drilling fluid, and leave the surface water-wet. This work’s main objective was to use biodegradable microemulsion systems as cleanup fluids in order to reduce the environmental impact. Three microemulsion systems were formulated, each composed of an oil phase, a surfactant and three different aqueous phases: glycerol, glycerol:water (mass ratio 1:1), and fresh water. The results show that all microemulsion systems were effective with 100% filter cake removal, with a removal time of less than 60 s. The wettability test and fluid compatibility analyses exhibited advantageous performances, without phase separation, variations in viscosity, gelation, or flocculation. The compressive strength and X-ray diffractometry (XRD) analysis showed the influence of the glycerol on the cement slurry properties, with the compressive strength resistance ranging from 8.0 to 10.7 MPa, and resulted in the formation of portlandite.

Aldosterone in panhypopitutarism: dynamic studies and therapeutic effects in Sheehan's syndrome

1986 ◽  
Vol 112 (3) ◽  
pp. 329-335 ◽  
Author(s):  
Fawzi Bakiri ◽  
Anne M. Riondel ◽  
Moulai Benmiloud ◽  
Michel B. Vallotton
Keyword(s):  
Thyroid Hormone ◽  
Control Group ◽  
Minor Role ◽  
Therapeutic Effects ◽  
Aldosterone Secretion ◽  
Before And After ◽  
Basal Plasma ◽  
Stimulation Tests ◽  
A Minor

Abstract. To appreciate the aldosterone secretion status in panhypopituitarism, the steroid response to stimulation was studied in a homogeneous group of 20 female patients presenting with global hypopituitarism. Specific effects of glucocorticoid and thyroid hormone deficiencies were also assessed by studying the same patients before and after cortisol (F) and cortisol plus thyroid hormone (F + T) substitution. The patients were submitted to two stimulation tests before and after each treatment: the orthostasis test (O-T) and the furosemide test (Furo-T). The results obtained in the 3 situations were compared, each patient serving as her own control. Comparison was also established with the results obtained in healthy women serving as control group. Basal plasma aldosterone levels in the untreated patients were not significantly different from those of the control group (5.43 ± 0.51 vs 7.16 ±0.80 ng/100 ml, mean ± sem). They were significantly lower after F (3.91 ± 0.42) and F + T substitution (3.31 ± 0.23) than those of untreated patients and controls. Response to both stimulations was blunted in the untreated patients (O-T: 14.10 ± 2.81; Furo-T: 9.78 ± 1.35) as compared to the control group (O-T: 26.46 ± 4.67; Furo-T: 23.96 ± 3.30). F treatment did not improve the response to either tests, (O-T: 11.42 ± 2.55; Furo-T: 10.32 ± 1.23). F + T treatment normalized the orthostasis response (20.83 ± 3.59) and increased the response to furosemide which remained, however, lower (15.28 ± 1.83) than in the control group. These results are in favour of a minor role of the pituitary in the regulation of aldosterone secretion. They emphasize the role of thyroid hormones which may act partly directly, partly through their effect on renin secretion.

scholarly journals Radiation-produced defects in germanium: experimental data and models of defects

2017 ◽  
Vol 51 (12) ◽  
pp. 1632
Author(s):  
V.V. Emtsev ◽  
D.S. Poloskin ◽  
G.A. Oganesyan ◽  
V.V. Kozlovski
Keyword(s):  
Experimental Data ◽  
Defect Formation ◽  
Deep Level ◽  
Minor Role ◽  
Radiation Defects ◽  
Electrical Measurements ◽  
Group V ◽  
Before And After ◽  
Transient Spectroscopy ◽  
A Minor

The problem of radiation-produced defects in n-Ge before and after n-> p conversion is discussed in the light of electrical data obtained by means of Hall effect measurements as well as Deep Level Transient Spectroscopy. The picture of the dominant radiation defects in irradiated n-Ge before n-> p conversion appears to be complicated, since they turn out to be neutral in n-type material and unobserved in the electrical measurements. It is argued that radiation-produced acceptors at ~ EC-0.2 eV previously ascribed to vacancy-donor pairs (E-centers) play a minor role in the defect formation processes under irradiation. Acceptor defects at ~ EV+0.1 eV are absolutely dominating in irradiated n-Ge after n-> p conversion. All the radiation defects under consideration were found to be dependent on the chemical group-V impurities. Together with this, they are concluded to be vacancy-related, as evidenced positron annihilation experiments. A detailed consideration of experimental data on irradiated n-Ge shows that the present model of radiation-produced defects adopted in literature should be reconsidered. DOI: 10.21883/FTP.2017.12.45178.8599

scholarly journals Effects of systemic glucocorticosteroids on peripheral neutrophil functions in asthmatic subjects: anex vivostudy

1995 ◽  
Vol 4 (4) ◽  
pp. 251-256 ◽  
Author(s):  
P. L. Paggiaro ◽  
L. Bancalari ◽  
D. Giannessi ◽  
W. Bernini ◽  
G. Lazzerini ◽  
...  
Keyword(s):  
Acute Exacerbation ◽  
Superoxide Anion ◽  
Normal Subjects ◽  
Minor Role ◽  
Neutrophil Chemotaxis ◽  
E Coli ◽  
Superoxide Anion Generation ◽  
Before And After ◽  
A Minor ◽  
Peripheral Neutrophil

In 21 asthmatic subjects, several functions of isolated peripheral neutrophils (chemokinesis and chemotaxis toward 10%E. coli; superoxide anion generation after PMA; leukotriene B4(LTB4) release from whole blood and isolated neutrophtls, before and after different stimuli) were evaluated during an acute exacerbation of asthma, and after 14 – 54 days of treatment with systemic glucocorticosteroids (GCS). During acute exacerbation, superoxide anion generation was higher in asthmatics than in eleven normal subjects (39.2 ± 14.1vs.25.2 ± 7.3 nmol, p < 0.05); there was a significant correlation between FEV1(% of predicted) and neutrophil chemotaxis (r = −0.52, p = 0.04). After treatment, there was no significant change in all neutrophil functions, except for a decrease in neutrophil chemotaxis in subjects who showed an FEV1increase > 20% after GCS treatment (from 131 ± 18 to 117 ± 21 μm, p = 0.005). Chemokinesis sicantly decreased in all subjects, and the changes significantly correlated with an arbitrary score of the total administered dose of GCS (r = 0.57, p < 0.05). These data suggest that neutrophil activation plays a minor role in asthma, and that treatment with GCS is not able to modify most functions of peripheral neutrophils in asthmatic subjects; chemotaxis seems to be related only to the severity of the asthma and it could reflect the improvement of the disease.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Produktivkraft als Versprechen

2016 ◽  
Vol 46 (185) ◽  
pp. 621-638 ◽  
Author(s):  
Christian Siefkes
Keyword(s):  
Private Consumption ◽  
Minor Role ◽  
Progressive Reduction ◽  
Internal Forces ◽  
A Minor

The ‘Fragment on Machines’ from Marx’s Grundrisse is often cited as an argument that the internal forces of capitalism will lead to its doom. But the argument that the progressive reduction of labor must doom capitalism lacks a proper foundation, as a comparison with the ‘Schemes of Reproduction’ given in Capital II shows. The latter, however, aren’t fully convincing either. In reality, more depends on the private consumption of capitalists than either model recognizes. Ultimately, most can be made of the ‘Fragment on Machines’ by reading it not as an exposure of capitalism’s internal contractions, but as a discussion of a possible communist future where labor (or work) will play but a minor role.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

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