Development and Application of Adjustable Frequency Pulse Jet Generating Tool to Improve Rate of Penetration in Deep Wells

Cui, Longlian; Zhang, Fucheng; Wang, Haige; Ge, Yong; Zhuo, Lubin; Li, Hong

doi:10.2118/155799-ms

Cited by 5 publications

(4 citation statements)

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“…Previous research on pulse drilling fluid has mainly centered on improving rock breaking efficiency and ROP [33,34]. There has been little analysis to date on the impact of pulse drilling fluid on cuttings transport.…”

Section: Introductionmentioning

confidence: 99%

Investigation: Cutting Transport Mechanism in Inclined Well Section under Pulsed Drilling Fluid Action

Zhu

Shen

2021

Energies

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Due to gravity, drilling cuttings are easily accumulated in an inclined well section, ultimately forming a cuttings bed, which places the drill pipe under strong friction torque. In severe cases, this can cause dragging, stuck drills, and broken drill tools. Because conventional drilling fluids are difficult to prevent the formation of cuttings in inclined well sections, a method of carrying cuttings with the pulsed drilling fluid to improve wellbore cleanness is proposed. Experiments and numerical simulations are conducted to investigate the effects of cuttings bed transport velocity, cuttings size, cuttings height, drill pipe rotation speed, cuttings bed mass, and roughness height. The optimal pulse parameters are determined per their respective impact on cuttings transport concerning varied periods, amplitudes, and duty cycles of the pulsed drilling fluid. Compared to cuttings transport under the conventional drilling fluid flow rate, the pulsed drilling fluid produces the turbulent dissipation rate, increases cuttings transport velocity, and thus improves the wellbore clearance rate.

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Section: Introductionmentioning

confidence: 99%

Investigation: Cutting Transport Mechanism in Inclined Well Section under Pulsed Drilling Fluid Action

Zhu

Shen

2021

Energies

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“…This provides a continuous impact on the cuttings by changing the flow rate of the drilling fluid. Pulsed jet drilling technology can effectively increase the drilling speed [27], and so downhole drilling tools using pulsed jets are equipped with variable-frequency pulse jet generators [28] and spiral pressure intensifiers [29]. Field experiments have shown that the use of pulsed drilling fluid reduces the effect of chipping and increases the efficiency of cuttings transport [30,31].To date, the focuses of most studies of cuttings transport have been on its behavior of cuttings under conventional drilling fluid flow conditions.…”

mentioning

confidence: 99%

Cuttings Transport Using Pulsed Drilling Fluid in the Horizontal Section of the Slim-Hole: An Experimental and Numerical Simulation Study

Zhu

Shen

et al. 2019

Energies

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Poor transport of cuttings in horizontal sections of small-bore well holes leads to high torque and increases the risk of the drill becoming stuck, reducing its service life and posing a threat to safe operation. Because the conventional cuttings transport method cannot effectively remove the cuttings bed, a transport method using pulsed drilling fluid based on a shunt relay mechanism is proposed. A three-layer numerical simulation model of cuttings transport in horizontal small-bore wells is established. Using both experiments and numerical simulations, the cuttings transport is studied in terms of the moving cuttings velocity, cuttings concentration, and distance of movement of the cuttings bed. By varying the pulsed drilling fluid velocity cycle, amplitude, and duty cycle at the annulus inlet, their effects on cuttings transport are analyzed, and the optimal pulse parameters are determined. The results show that the use of pulsed drilling fluid can effectively enhance the moving cutting velocity and transport distance of the cuttings bed, reduce the cuttings concentration, and improve wellbore cleaning.According to experimental investigations and numerical simulations of cuttings transport, this is subject to a number of variables, including cuttings size, drill pipe rotation, and drill pipe eccentricity. Drill pipe rotation will increase the transport efficiency of cuttings in a horizontal wellbore [14,15]. When the drill pipe eccentricity exceeds a certain value, the height of the cuttings bed increases sharply, resulting in high torque and the possibility of the drill becoming stuck [16]. If the drill pipe rotation speed is too high and the eccentricity is too large, the annulus pressure drop in a horizontal well will increase [17,18], enhancing the resistance and the torque generated in the liquid-solid mixture [19]. Large cuttings size will reduce the transport efficiency and is not conducive to wellbore cleaning [20][21][22][23]. The higher the apparent viscosity of the drilling fluid, the better is the transport performance of the cuttings at low drilling fluid velocities, but the greater is the pressure loss [24][25][26].The conventional method for cuttings transport uses a constant drilling fluid flow rate. According to simulations based on the three-layer numerical model, when the height of the cuttings bed in the annulus exceeds a critical value, the movement distance of cuttings bed is reduced to the extent that the cleaning effect in the wellbore cannot reach its desired target. To improve transport, a method with pulsed drilling fluid has been proposed. This provides a continuous impact on the cuttings by changing the flow rate of the drilling fluid. Pulsed jet drilling technology can effectively increase the drilling speed [27], and so downhole drilling tools using pulsed jets are equipped with variable-frequency pulse jet generators [28] and spiral pressure intensifiers [29]. Field experiments have shown that the use of pulsed drilling fluid reduces the effect of chipping and increases the effi...

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“…1,2 Therefore, it is urgent to seek available cost-effective rockbreaking methods for improving the penetration rate in hard formations of deep wells. 1,2 Therefore, it is urgent to seek available cost-effective rockbreaking methods for improving the penetration rate in hard formations of deep wells.…”

mentioning

confidence: 99%

“…hardness, and abrasiveness of the rock increase as the well depth increases, resulting in poorer drilling ability, lower penetration rate, longer drilling cycles, and higher cost. 1,2 Therefore, it is urgent to seek available cost-effective rockbreaking methods for improving the penetration rate in hard formations of deep wells. 3,4 A high-pressure waterjet is considered one of the most promising assisted rock-breaking technologies.…”

mentioning

confidence: 99%

Research on the modulation mechanism and rock breaking efficiency of a cuttings waterjet

Wang

Zhao

et al. 2019

Energy Science & Engineering

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The feasibility of a cuttings waterjet directly modulated in the bottom hole is discussed from the aspects of cuttings suction and rock‐breaking efficiency. The particle waterjet modulation mechanism using a Helmholtz oscillating cavity is studied through numerical simulation and the rock‐breaking efficiency of five types of particles (including cuttings, steel balls, steel emery, garnet, and silicon carbide) is studied through experiment. The influences of particle parameters (such as diameter, density, and concentration) and operation parameters (such as standoff distance, pump pressure, and confining pressure) on the suction and rock‐breaking effect of different particles are analyzed. The results show that all particle types with different parameters could be indrawn into the Helmholtz oscillating cavity with two symmetrical suction ports and could be accelerated to considerable velocity amplitude to impact rock. The rock‐breaking efficiency of pure cuttings was lower than fractional cuttings (ie, 50% cuttings and 50% steel balls) and pure steel balls, but the pure cuttings can be used as an effective assisted rock‐breaking method. The research results lay a foundation for development of a cuttings waterjet directly modulated in the bottom hole for assisting rock‐breaking technology.

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Development and Application of Adjustable Frequency Pulse Jet Generating Tool to Improve Rate of Penetration in Deep Wells

Cited by 5 publications

References 0 publications

Investigation: Cutting Transport Mechanism in Inclined Well Section under Pulsed Drilling Fluid Action

Investigation: Cutting Transport Mechanism in Inclined Well Section under Pulsed Drilling Fluid Action

Cuttings Transport Using Pulsed Drilling Fluid in the Horizontal Section of the Slim-Hole: An Experimental and Numerical Simulation Study

Research on the modulation mechanism and rock breaking efficiency of a cuttings waterjet

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