Prediction of Penetration Rate for PDC Bits Using Indices of Rock Drillability, Cuttings Removal, and Bit Wear

2020 ◽  
Author(s):  
Ahmed Z Mazen ◽  
Nejat Rahmanian ◽  
Iqbal Mujtaba ◽  
Ali Hassanpour
Keyword(s):  
Penetration Rate ◽  
Bit Wear ◽  
Rock Drillability

Property Analysis for Correlation of Specific Energy with Penetration Rate and Bit Wear Rate

2011 ◽  
Vol 367 ◽  
pp. 547-553
Author(s):  
B. Adebayo ◽  
W. A. Bello
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Wear Rate ◽  
Uniaxial Compressive Strength ◽  
Specific Energy ◽  
Penetration Rate ◽  
Point Load ◽  
Coefficient Of Correlation ◽  
Rock Samples ◽  
Bit Wear

This study evaluates rock properties for correlation of specific energy with penetration rate and bit wear rate. In order to achieve these objectives five rock samples were obtained from the study area. These samples were tested in the laboratory for uniaxial compressive strength and tensile strength using 1100kN compression machine and point load tester respectively. Also, the mineral composition of the samples was determined by thin section examination. Bit deterioration was measured with digital vernier calliper at regular intervals. The specific energy was determined from field data using empirical equations. The results of the uniaxial compressive strength of the five rock samples varied from 165-320 MPa and were classified as having very high compressive strength characteristics. The point load strength index of the samples had values ranging from 5.50 – 10.67 MPa representing the tensile strength. The result of the statistical correlation matrix revealed that penetration rate and bit wear rate are dominant factors affecting the prediction of specific energy having high coefficient of correlation. The regression model had multiple coefficient of correlation of R2 = 0.893 which means that 89.3% of variation in specific energy could be attributed to variation in penetration rate and bit wear rate. Ultimately, computer programme DRILLING PROFESSIONAL 2009 was developed to compute penetration rate, wear rate and specific energy when necessary inputs are supplied. This gives quarry operators advance information on time of drilling and bit consumption.

Ice ridges in landfast ice of Shokal'skogo Strait

2019 ◽  
Vol 12 (3) ◽  
pp. 16-26
Author(s):  
Victor V. Kharitonov
Keyword(s):  
Penetration Rate ◽  
Hot Water ◽  
First Year ◽  
Height Ratio ◽  
Long Distance ◽  
Cross Sectional ◽  
Landfast Ice ◽  
Thermal Drilling ◽  
Severnaya Zemlya ◽  
Severnaya Zemlya Archipelago

Three first-year ice ridges have been examined with respect to geometry and morphology in landfast ice of Shokal'skogo Strait (Severnaya Zemlya Archipelago) in May 2018. Two of the studied ice ridges were located on the edge of the ridged field and were part of it, because their keels extended for a long distance deep into this field. Ice ridges characteristics are discussed in the paper. These studies were conducted using hot water thermal drilling with computer recording of the penetration rate. Boreholes were drilled along the cross-section of the ridge crest at 0.25 m intervals. Cross-sectional profiles of ice ridges are illustrated. The maximal sail height varied from 2.9 up to 3.2 m, the maximal keel depth varied from 8.5 up to 9.6 m. The average keel depth to sail height ratio varied from 2.8 to 3.3, and the thickness of the consolidated layer was 2.5-3.5 m. The porosity of the non-consolidated part of the keel was about 23-27%. The distributions of porosity versus depth for all ice ridges are presented.

Analysis of Efficiency of Drilling of Large-Diameter Wells With a Profiled Wing Bit / Badania Efektywności Wiercenia Studni Wielkośrednicowych Świdrem Skrawającym z Profilowanymi Skrzydłami

2012 ◽  
Vol 57 (2) ◽  
pp. 363-373
Author(s):  
Jan Macuda
Keyword(s):  
Average Rate ◽  
Large Diameter ◽  
Open Pit ◽  
Mechanical Parameters ◽  
Drilling Rate ◽  
Geological Conditions ◽  
Rock Drillability ◽  
Drilling Technology ◽  
Weight On Bit ◽  
Rotary Speed

Abstract In Poland all lignite mines are dewatered with the use of large-diameter wells. Drilling of such wells is inefficient owing to the presence of loose Quaternary and Tertiary material and considerable dewatering of rock mass within the open pit area. Difficult geological conditions significantly elongate the time in which large-diameter dewatering wells are drilled, and various drilling complications and break-downs related to the caving may occur. Obtaining higher drilling rates in large-diameter wells can be achieved only when new cutter bits designs are worked out and rock drillability tests performed for optimum mechanical parameters of drilling technology. Those tests were performed for a bit ø 1.16 m in separated macroscopically homogeneous layers of similar drillability. Depending on the designed thickness of the drilled layer, there were determined measurement sections from 0.2 to 1.0 m long, and each of the sections was drilled at constant rotary speed and weight on bit values. Prior to drillability tests, accounting for the technical characteristic of the rig and strength of the string and the cutter bit, there were established limitations for mechanical parameters of drilling technology: P ∈ (Pmin; Pmax) n ∈ (nmin; nmax) where: Pmin; Pmax - lowest and highest values of weight on bit, nmin; nmax - lowest and highest values of rotary speed of bit, For finding the dependence of the rate of penetration on weight on bit and rotary speed of bit various regression models have been analyzed. The most satisfactory results were obtained for the exponential model illustrating the influence of weight on bit and rotary speed of bit on drilling rate. The regression coefficients and statistical parameters prove the good fit of the model to measurement data, presented in tables 4-6. The average drilling rate for a cutter bit with profiled wings has been described with the form: Vśr= Z ·Pa· nb where: Vśr- average drilling rate, Z - drillability coefficient, P - weight on bit, n - rotary speed of bit, a - coefficient of influence of weight on bit on drilling rate, b - coefficient of influence of rotary speed of bit on drilling rate. Industrial tests were performed for assessing the efficiency of drilling of large-diameter wells with a cutter bit having profiled wings ø 1.16 m according to elaborated model of average rate of drilling. The obtained values of average rate of drilling during industrial tests ranged from 8.33×10-4 to 1.94×10-3 m/s and were higher than the ones obtained so far, i.e. from 181.21 to 262.11%.

Study of Corrosion Penetration Rate on Composite Materials EN AC-43100 (AlSi10Mg (b)) + SiC*

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Prantasi Harmi Tjahjanti ◽  
◽  
Darminto Darminto ◽  
Wibowo Harso Nugroho ◽  
Andita N.F. Ganda ◽  
...  
Keyword(s):  
Composite Materials ◽  
Penetration Rate

scholarly journals Replacement of Albumin by Preovulatory Oviductal Fluid in Swim-Up Sperm Preparation Method Modifies Boar Sperm Parameters and Improves In Vitro Penetration of Oocytes

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1202
Author(s):  
Sergio Navarro-Serna ◽  
Evelyne París-Oller ◽  
Ondrej Simonik ◽  
Raquel Romar ◽  
Joaquín Gadea
Keyword(s):  
Calcium Concentration ◽  
Preparation Method ◽  
Culture Media ◽  
Penetration Rate ◽  
Sperm Parameters ◽  
High Concentration ◽  
Sperm Preparation ◽  
Boar Sperm ◽  
Oviductal Fluid

More suitable and efficient methods to protect gametes from external harmful effects during in vitro handling can be achieved by adding preovulatory porcine oviductal fluid (pOF) to in vitro culture media. The objective of this study was to assess the swim-up procedure’s suitability as a sperm selection method using a medium supplemented with 1mg/mL BSA, 1% preovulatory pOF (v/v), 1% v/v pOF plus 1mg/mL BSA, and 5mg/mL BSA. After selection, various sperm parameters were studied, such as sperm recovery rate, sperm morphology, motility (by CASA), vitality, acrosome status and intracellular calcium (by flow cytometry) and ability to penetrate oocytes in vitro. Around 2% of sperm were recovered after swim-up, and the replacement of BSA by pOF showed a beneficial reduction of motility parameters calcium concentration, resulting in an increased penetration rate. The combination of albumin and oviductal fluid in the medium did not improve the sperm parameters results, whereas a high concentration of BSA increased sperm morphological abnormalities, motility, and acrosome damage, with a reduction of calcium concentration and penetration rate. In conclusion, the replacement of albumin by preovulatory oviductal fluid in the swim-up sperm preparation method modifies boar sperm parameters and improves the in vitro penetration of oocytes.

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