Experimental study on hydraulic isolation mechanism during hydra-jet fracturing

Sheng, Mao; Li, G.; Huang, Zhongwei; Tian, Shouceng; Qu, Hai

doi:10.1016/j.expthermflusci.2012.09.014

Cited by 23 publications

(9 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some parts of the SC-CO 2 jet expand and flow attached on the specimen surface, forming a wall-attached jet. Due to the existence of high-velocity jet core, the pressure of the annular region around the jet core drops, resulting in the low-pressure hydro-jet O-ring which was reported by Huang et al and Sheng et al [9,32]. As a result, the strong mixing of CO 2 in the annular region and the CO 2 jet is also monitored by using HSP in Figure 18b, which is in accord with the numerical results.…”

Section: The Similar Experiments Of Sc-co 2 Jet Flowingsupporting

confidence: 85%

“…Compared with water jets, the usage of SC-CO 2 jet shows many advantages for rock breaking, such as lower threshold pressure, fast drilling and a high rate of penetration [5,8]. High-pressure jet fracturing is a novel fracturing technology due to the advantages of multi-stage pin-point fracturing and less utilization of mechanical packers [9]. Therefore, SC-CO 2 jet fracturing, combining the advantages of both water hydraulic-jet fracturing and SC-CO 2 fluid, is proposed in order to increase shale gas production and lowered energy costs.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Flow Characteristics of Supercritical Carbon Dioxide (SC-CO2) Jet Fracturing in Limited Perforation Scenarios

et al. 2020

View full text Add to dashboard Cite

Supercritical carbon dioxide (SC-CO2) jet fracturing is a promising alternative for shale gas fracturing instead of water. However, most studies pay more attention to the fracture generation and ignore the flow characteristic of SC-CO2 jet fracturing in limited perforation scenarios. To accurately explore the flow field in a limited perforation tunnel, a numerical model of a SC-CO2 jet in a limited perforation tunnel before fracture initiation is established based on the corresponding engineering background. The comparison between the numerical simulation and experiments has proved that the model is viable for this type of analysis. By using the numerical method, the flow field of the SC-CO2 jet fracturing is analyzed, and influencing factors are discussed later. The verification and validation show that the numerical model is both reliable and accurate. With the dramatic fluctuating of turbulent mixing in a fully developed region, there is an apparent increase in the CO2 density and total pressure during limited perforation. When the z increases from 10 times r0 to 145 times r0, the velocity on the perforation wall surface would decrease below 0 m/s, resulting in backflow in the perforation tunnel. The structure of the nozzle, including the outlet length and outlet diameters, significantly affects the axial velocity and boosting pressure in the perforation tunnel. The highest total pressure exists when the nozzle length-to-radius ratio is 2. The maximum velocity of the jet core drops from 138.7 to 78 m/s, and the “hydraulic isolating ring” starts disappearing when the radius changes from 1 to 1.5 mm. It is necessary to increase the aperture ratio as much as possible to ensure pressurization but not over 1. Based on a similar theory high-speed photography results clearly show that the SC-CO2 develops to fully jetting in only 0.07 s and a strong mixing exists in the annular region between the jet core and the surroundings, according with the numerical simulation. This study should be helpful for scholars to comprehensively understand the interaction between the SC-CO2 jet and perforation, which is beneficial for studying SC-CO2 fracturing.

show abstract

Section: The Similar Experiments Of Sc-co 2 Jet Flowingsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

The Flow Characteristics of Supercritical Carbon Dioxide (SC-CO2) Jet Fracturing in Limited Perforation Scenarios

et al. 2020

View full text Add to dashboard Cite

show abstract

“…In this paper, radial borehole fracturing technology means fracturing based on the existing radial boreholes drilling by hydraulic jetting technology. Based on the mature technology of hydraulic jetting [6][7][8][9], preliminary conclusions have been obtained in the research on the radial borehole fracturing at a certain level, which indicates that this technology can change the inherent morphology of fracture and effectively improve the effect of reservoir stimulation [10,11].…”

Section: Introductionmentioning

confidence: 99%

Research and Application of Radial Borehole Fracturing Based on Numerical Simulation

2019

Geofluids

View full text Add to dashboard Cite

The radial borehole fracturing technology has been applied in a certain number of oilfields with good results being achieved. However, the morphology and variation of fracture still require further study. In this paper, the reservoir model based on formation fluid-solid coupling equation is established with the extended finite element method (XFEM) in ABAQUS, and the fracture morphologies in the single-radial borehole, vertical multiradial borehole, and horizontal multiradial borehole are simulated and analyzed with criteria of maximum principal stress and maximum energy release rate as the damage mechanism. Moreover, the accuracy of numerical simulation results is verified with the large-scale true 3D physical simulation experiment. The results show that the induced stress field along the radial borehole during fracturing is the root cause of fracture directional propagation along the radial borehole whose effective guidance distance reaches 40 m. The vertical multiradial borehole can effectively enhance fracture directional propagation and is capable of reducing fracture initiation pressure. In the horizontal multiradial borehole, the major fracture propagating along each radial borehole is formed in the remote-borehole area, and the secondary fracture connecting the neighboring radial boreholes is formed in the near-borehole zone. Coordination of major and secondary fractures can effectively increase the drainage area and reduce the flow resistance in the near-borehole zone. Based on the research on fracture morphology of multiradial borehole fracturing, the scheme of radial borehole arrangement is optimized and verified through numerical simulation of deliverability. The final optimum borehole arrangement scheme is the intersectional angle of 45°between four orthogonal radial boreholes and horizontal maximum principal stress.

show abstract

“…Another example of technology merging is the high-pressure water jet breaking technology and its combination with the conventional drill bit to develop the jet drilling technology, which can greatly improve the efficiency of drilling [14,15]. Moreover, the high-pressure water jet cutting technology and the conventional hydraulic fracturing are combined to develop the hydraulic jet fracturing technology, which can be utilized to make directionally controllable cracks in the strata, resulting in a greater increase in the recovery ratio of exploitation for oil and gas, especially for the unconventional oil and gas resources [16].…”

Section: Introductionmentioning

confidence: 99%

“…Nozzle is a fundamental component in the implementation of H-PWJT. The exploration of nozzle with good hydraulic performance is a key precondition for the smooth and efficient implementation of H-PWJT and other related technologies as the ones mentioned above [5][6][7][8][9][10][11][12][13][14][15][16]. This study proposes a combination of EB and nozzle's structural design.…”

Section: Introductionmentioning

confidence: 99%

Bionic optimum design of straight cone nozzle and the effectiveness evaluation of reducing fluid resistance

Wen

Chen

et al. 2019

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

High-pressure water jet technology is a clean and effective approach to break, cut or clean solid materials. The nozzle's hydraulic performance determines the efficiency and quality of the high-pressure water jet technology implementation. The fluid resistance reduction technology of bionic non-smooth surface is applied to the structural design of the straight cone nozzle successfully. The circular groove is selected as the bionic unit. The selection results in the investigation and development of a bionic straight cone nozzle with the optimum hydraulic performance. Moreover, the separated nozzle machining method is successfully implemented. A comprehensive approach that implements the orthogonal experiment, high-pressure water jets' impact forces testing and range analysis results in the optimization of the bionic straight cone nozzle's structure. The optimal structural parameters of the nozzle as follows: the outlet diameter is 4 mm, length-to-diameter ratio is 2.5, contraction angle is 60°, the circular groove width is 3 mm, the circular groove depth is 2 mm and the circular groove number is 2. In addition, the circular grooves are uniformly arranged on the surface of the straight cone nozzle's internal chamber resulting in reduction of the fluid resistance effectively. Under the same experimental conditions, the impact forces of high-pressure water jets produced by the bionic straight cone nozzles are greater in comparison with the impact forces of high-pressure water jets produced by the ordinary straight cone nozzles. The average rate of fluid resistance reduction of bionic straight cone nozzles is up to 2.33%. Furthermore, the results of CFD numerical simulation show that the circular grooves at the contraction and the outlet sections can also reduce the high-pressure water flow resistance effectively. In the meantime, the opposite rotating vortexes in the circular grooves are the main reason for the reduction in fluid resistance of the bionic straight cone nozzle.

show abstract

Experimental study on hydraulic isolation mechanism during hydra-jet fracturing

Cited by 23 publications

References 15 publications

The Flow Characteristics of Supercritical Carbon Dioxide (SC-CO2) Jet Fracturing in Limited Perforation Scenarios

The Flow Characteristics of Supercritical Carbon Dioxide (SC-CO2) Jet Fracturing in Limited Perforation Scenarios

Research and Application of Radial Borehole Fracturing Based on Numerical Simulation

Bionic optimum design of straight cone nozzle and the effectiveness evaluation of reducing fluid resistance

Contact Info

Product

Resources

About