Low Invasion Corehead Reduces Mud Invasion While Improving Performances

1994 ◽  
Vol 116 (4) ◽  
pp. 258-267
Author(s):  
G. M. Clydesdale ◽  
A. Leseultre ◽  
E. Lamine
Keyword(s):  
Flow Visualization ◽  
High Speed ◽  
Drilling Fluid ◽  
Polycrystalline Diamond ◽  
Design Flow ◽  
Rate Of Penetration ◽  
The Core ◽  
Drill Bits ◽  
Hydraulic Design ◽  
Bit Life

A corehead was designed, manufactured and tested to reduce fluid invasion of the core. This is obtained by minimizing the exposure time of the core to the drilling fluid in increasing the rate of penetration (ROP). The design incorporates a medium heavyset polycrystalline diamond compact (PDC) cutting structure developed in accordance with cutting models and balancing methods used for drill bits. The highest ROP is achieved by a particular hydraulic design: flow ports shape and positioning to clean the cutting structure enhance the drilled cuttings removal while preventing drilling fluid in the throat of the corehead. Moreover, an internal lip works with a special inner barrel shoe to effectively seal off mud flow from the throat. All the design features have been subjected to laboratory tests, including measurement of pressure drop across the corehead and flow visualization studies. Flow visualization tests include high-speed filming of the flow and paint tracing to indicate the special flow pattern. In conjunction with lab tests, a numerical simulation was performed using fluid dynamics software to optimize hydraulic parameters. The low invasion core bit has been used in numerous applications. The performance achieved was significantly better than the average achieved over a period of years using various PDC coreheads. The rate of penetration was increased by a factor of 4.8 and bit life by 2.3 (often with reusable condition).

Life Models for Small-Diameter Polycrystalline Diamond Compact Bits in Hard Abrasive Media

1986 ◽  
Vol 108 (4) ◽  
pp. 310-314
Author(s):  
C. L. Hough ◽  
B. Das ◽  
T. G. Rozgonyi
Keyword(s):  
Cutting Speed ◽  
Small Diameter ◽  
Polycrystalline Diamond ◽  
Prediction Equation ◽  
Logarithmic Model ◽  
Drill Bits ◽  
Rate Versus ◽  
Rotary Speed ◽  
Bit Life ◽  
Polycrystalline Diamond Compact

Mathematical models for bit life of polycrystalline diamond compact (PDC) drill bits were developed for drilling small holes in hard abrasive media. Based on the wear-out criterion of an average 0.060 in. (1.5 mm) flank wear land, bit life equations were formulated in three forms: bit life versus rotary speed and feed rate, bit life versus rotary speed and penetration rate, and wear rate versus cutting speed and cutter engagement area. The traditional linear-logarithmic model proved inadequate to describe bit life, whereas the quadratic-logarithmic model provided the best bit life prediction equation. Consequently, it would be possible to predict the optimum economical drilling conditions more accurately by employing a quadratic-logarithmic based bit life equation. The equation demonstrated the ability to predict the bit life precisely under different modes of wear.

Analysis of Adsorption Mechanism of Anti-Balling Additive for Drilling Engineering on Metal Surface

2013 ◽  
Vol 437 ◽  
pp. 551-554
Author(s):  
Cha Ma ◽  
Yu Ping Yang ◽  
Long Li
Keyword(s):  
Metal Surface ◽  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Fluid System ◽  
Adsorption Effect ◽  
Rate Of Penetration ◽  
Drill Bits ◽  
Drilling Engineering

Due to the repeated cracking caused by the adsorption of cuttings on the surface of drilling bits and BHA during drilling operation, the rate of penetration (ROP) could reduce remarkably. The anti-balling additive for drilling fluids (ABA) could eliminate the adsorption effect of cuttings, and increase ROP significantly. In this paper, the mechanism of eliminating the adsorption effect of cuttings was investigated in details. The results indicate that ABA can form multilayer chemical and physical adsorption on the surface of drill bits and BHA in the form of oriented adsorption of organic phosphine, which is of great importance to the design of drilling fluid system and field operation to raise ROP.

scholarly journals The Performance of Polycrystalline Diamond (PCD) Tools Machined by Abrasive Grinding and Electrical Discharge Grinding (EDG) in High-Speed Turning

2021 ◽  
Vol 5 (2) ◽  
pp. 34
Author(s):  
Guangxian Li ◽  
Ge Wu ◽  
Wencheng Pan ◽  
Rizwan Abdul Rahman Rashid ◽  
Suresh Palanisamy ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
High Speed ◽  
Flank Wear ◽  
Polycrystalline Diamond ◽  
Machining Efficiency ◽  
Crater Wear ◽  
Wear Process ◽  
High Speed Turning ◽  
Tools Wear ◽  
Pcd Tools

Polycrystalline diamond (PCD) tools are widely used in industry due to their outstanding physical properties. However, the ultra-high hardness of PCD significantly limits the machining efficiency of conventional abrasive grinding processes, which are utilized to manufacture PCD tools. In contrast, electrical discharge grinding (EDG) has significantly higher machining efficiency because of its unique material removal mechanism. In this study, the quality and performance of PCD tools machined by abrasive grinding and EDG were investigated. The performance of cutting tools consisted of different PCD materials was tested by high-speed turning of titanium alloy Ti6Al4V. Flank wear and crater wear were investigated by analyzing the worn profile, micro morphology, chemical decomposition, and cutting forces. The results showed that an adhesive-abrasive process dominated the processes of flank wear and crater wear. Tool material loss in the wear process was caused by the development of thermal cracks. The development of PCD tools’ wear made of small-sized diamond grains was a steady adhesion-abrasion process without any catastrophic damage. In contrast, a large-scale fracture happened in the wear process of PCD tools made of large-sized diamond grains. Adhesive wear was more severe on the PCD tools machined by EDG.

scholarly journals Real-Time Measurement of Drilling Fluid Rheological Properties: A Review

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3592
Author(s):  
Naipeng Liu ◽  
Di Zhang ◽  
Hui Gao ◽  
Yule Hu ◽  
Longchen Duan
Keyword(s):  
Decision Making ◽  
Rheological Properties ◽  
Real Time ◽  
Drilling Fluid ◽  
Time Measurement ◽  
Decision Making Process ◽  
Rate Of Penetration ◽  
The Real ◽  
Real Time Measurement ◽  
Fluid Properties

The accurate and frequent measurement of the drilling fluid’s rheological properties is essential for proper hydraulic management. It is also important for intelligent drilling, providing drilling fluid data to establish the optimization model of the rate of penetration. Appropriate drilling fluid properties can improve drilling efficiency and prevent accidents. However, the drilling fluid properties are mainly measured in the laboratory. This hinders the real-time optimization of drilling fluid performance and the decision-making process. If the drilling fluid’s properties cannot be detected and the decision-making process does not respond in time, the rate of penetration will slow, potentially causing accidents and serious economic losses. Therefore, it is important to measure the drilling fluid’s properties for drilling engineering in real time. This paper summarizes the real-time measurement methods for rheological properties. The main methods include the following four types: an online rotational Couette viscometer, pipe viscometer, mathematical and physical model or artificial intelligence model based on a Marsh funnel, and acoustic technology. This paper elaborates on the principle, advantages, limitations, and usage of each method. It prospects the real-time measurement of drilling fluid rheological properties and promotes the development of the real-time measurement of drilling rheological properties.

Hydraulic Design of Inlet Guide Vane and its Full Flow Passage Numerical Simulation on Centrifugal Pump

2014 ◽  
Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Zhenlin Li ◽  
Xin Zhou ◽  
Zizhe Wang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Guide Vane ◽  
Hydraulic Performance ◽  
Design Flow ◽  
Inlet Guide Vane ◽  
Hydraulic Efficiency ◽  
Flow Passage ◽  
Setting Angle ◽  
Hydraulic Design

In order to effectively improve hydraulic performance of centrifugal pump on off-conditions, the hydraulic design of inlet guide vane (IGV) was completed by adopting two dimensional theory in-house code based on one kind of IS series of centrifugal pump, which can achieve pre-whirl regulation of centrifugal pump. During design process the trailing edge of vane is assumed as equal velocity moment condition, and the distribution of vane setting angle along meridional streamline is also given as a quartic function firstly, the camber line is then drawn by point-by-point integration method and thickened at both sides along circumferential direction. With local vortex dynamics diagnosis theory, the optimal improvement of vane space shape can be finished by adjusting the design parameters of vane setting angle distribution coefficient ap. The full flow passage numerical simulations of centrifugal pump with IGV device are completed to analyze the influence of pre-whirl regulation on hydraulic performance of centrifugal pump under various pre-whirl angles. The results show that the pre-whirl regulation can improve the hydraulic performance of centrifugal pump on off-conditions. Under the positive pre-whirl regulation conditions, the best efficient point shift to small flow rate zone, and under the negative pre-whirl regulation conditions it moves to large flow rate zone. Compared with the pump without IGV device at the same flow rate condition of 0.8Q (Q the design flow rate), the hydraulic efficiency of centrifugal pump with IGV device improves obviously and reaches up to 1.43%. Meanwhile compared with that installed with the straight vanes designed based on the traditional theory, the inner flow field of centrifugal pump with the designed vanes improves and the overall hydraulic efficiency of centrifugal pump is somewhat increased.

Behavior of Unsteady Turbulent Starting Round Jets

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Neerav Abani ◽  
Jaal B. Ghandhi
Keyword(s):  
High Speed ◽  
Penetration Rate ◽  
Injection Rate ◽  
Injection Velocity ◽  
Time Varying ◽  
Velocity Change ◽  
Rate Of Penetration ◽  
Round Jets ◽  
The Difference ◽  
Sudden Decrease

Turbulent starting jets with time-varying injection velocities were investigated using high-speed schlieren imaging. Two solenoid-controlled injectors fed a common plenum upstream of an orifice; using different upstream pressures and actuation times, injection-rate profiles with a step increase or decrease in injection velocity were tested. The behavior of the jet was found to be different depending on the direction of the injection-velocity change. A step increase in injection velocity resulted in an increased rate of penetration relative to the steady-injection case, and a larger increase in injection velocity resulted in an earlier change in the tip-penetration rate. The step-increase data were found to be collapsed by scaling the time by a convective time scale based on the tip location at the time of the injection-velocity change and the difference in the injection velocities. A sudden decrease in injection velocity to zero was found to cause a deviation from the corresponding steady-pressure case at a time that was independent of the initial jet velocity, i.e., it was independent of the magnitude of the injection-velocity change. Two models for unsteady injection from the literature were tested and some deficiencies in the models were identified.

scholarly journals Laboratory Study on Core Fracturing Simulations for Wellbore Strengthening

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Biao Ma ◽  
Xiaolin Pu ◽  
Zhengguo Zhao ◽  
Hao Wang ◽  
Wenxin Dong
Keyword(s):  
Bearing Capacity ◽  
Laboratory Study ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
The Core ◽  
Fracture Pressure ◽  
Fluid Systems ◽  
Fracturing Process ◽  
Wellbore Strengthening

The lost circulation in a formation is one of the most complicated problems that have existed in drilling engineering for a long time. The key to solving the loss of drilling fluid circulation is to improve the pressure-bearing capacity of the formation. The tendency is to improve the formation pressure-bearing capacity with drilling fluid technology for strengthening the wellbore, either to the low fracture pressure of the formation or to that of the naturally fractured formation. Therefore, a laboratory study focused on core fracturing simulations for the strengthening of wellbores was conducted with self-developed fracture experiment equipment. Experiments were performed to determine the effect of the gradation of plugging materials, kinds of plugging materials, and drilling fluid systems. The results showed that fracture pressure in the presence of drilling fluid was significantly higher than that in the presence of water. The kinds and gradation of drilling fluids had obvious effects on the core fracturing process. In addition, different drilling fluid systems had different effects on the core fracture process. In the same case, the core fracture pressure in the presence of oil-based drilling fluid was less than that in the presence of water-based drilling fluid.

Application of R/S Rheometer in Low Temperature Drilling Fluid Rheology Determination

2012 ◽  
Vol 490-495 ◽  
pp. 3114-3118
Author(s):  
Xiao Ling Jiang ◽  
Zong Ming Lei ◽  
Kai Wei
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Low Temperature ◽  
High Speed ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Rheological Parameter ◽  
Fluid Temperature ◽  
Fluid Rheology ◽  
Rotary Viscometer

With six-speed rotary viscometer measuring the rheology of drilling fluid at low temperature, during the high-speed process, the drilling fluid temperature is not constant at low temperature, which leads to the inaccuracy in rheological measurement. When R/S rheometer is used cooperating with constant low-temperature box , the temperature remains stable during the process of determining the drilling fluid rheology under low temperature. The R/S rheometer and the six-speed rotational viscometer are both coaxial rotational viscometers, but they work in different ways and the two cylindrical clearance between them are different.How to make two viscometer determination result can maintain consistent?The experimental results show that, The use of R/S rheometer, with the shear rate for 900s-1 shear stress values instead of six speed rotary viscometer shear rate for 1022s-1 shear stress values.Then use two-point formula to calculate rheological parameters.The R/S rheometer rheological parameter variation with temperature has a good linear relationship,Can better reflect the rheological properties of drilling fluids with low temperature changerule

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