A new method for evaluation of fracture network formation capacity of rock

Guo, Tiankui; Zhang, Shicheng; Ge, Hongkui; Wang, Xiaoqiong; Lei, Xin; Xiao, Bo

doi:10.1016/j.fuel.2014.10.017

Cited by 156 publications

(64 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The surface fracture density in the experiment was found to be decreased with rock hardness, which varied from 17.2 m −1 for sandstone to 9.3 m −1 for granite. Depending on the orientation of rock discontinuities, The applicability of SCDA on the fracturing of rock has been studied by Guo et al [69] by manipulating the gradual pressure development in SCDA to quantitatively characterize the growth of fracture network in an array of rock specimens ranging from Granite to siltstone. The surface fracture density in the experiment was found to be decreased with rock hardness, which varied from 17.2 m −1 for sandstone to 9.3 m −1 for granite.…”

Section: Potential Applications Of Soundless Chemical Demolition Agentmentioning

confidence: 99%

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

2016

View full text Add to dashboard Cite

Global energy and material consumption are expected to rise in exponential proportions during the next few decades, generating huge demands for deep earth energy (oil/gas) recovery and mineral processing. Under such circumstances, the continuation of existing methods in rock fragmentation in such applications is questionable due to the proven adverse environmental impacts associated with them. In this regard; the possibility of using more environmentally friendly options as Soundless Chemical Demolition Agents (SCDAs) play a vital role in replacing harmful conventional rock fragmentation techniques for gas; oil and mineral recovery. This study reviews up to date research on soundless cracking demolition agent (SCDA) application on rock fracturing including its limitations and strengths, possible applications in the petroleum industry and the possibility of using existing rock fragmentation models for SCDA-based rock fragmentation; also known as fracking. Though the expansive properties of SCDAs are currently used in some demolition works, the poor usage guidelines available reflect the insufficient research carried out on its material's behavior. SCDA is a cementitious powdery substance with quicklime (CaO) as its primary ingredient that expands upon contact with water; which results in a huge expansive pressure if this CaO hydration reaction occurs in a confined condition. So, the mechanism can be used for rock fragmentation by injecting the SCDA into boreholes of a rock mass; where the resulting expansive pressure is sufficient to create an effective fracture network in the confined rock mass around the borehole. This expansive pressure development, however, dependent on many factors, where formation water content creates a negative influence on this due to required greater degree of hydration under greater water contents and temperature creates a positive influence by accelerating the reaction. Having a precise understanding of the fracture propagation mechanisms when using SCDA is important due to the formation of complex fracture networks in rocks. Several models can be found in the literature based on the tangential and radial stresses acting on a rock mass surrounding an SCDA charged borehole. Those fracture models with quasi-static fracturing mechanism that occurs in Mode I type tensile failure show compatibility with SCDA fracturing mechanisms. The effect of borehole diameter, spacing and the arrangement on expansive pressure generation and corresponding fracture network generation is important in the SCDA fracturing process and effective handling of them would pave the way to creating an optimum fracture network in a targeted rock formation. SCDA has many potential applications in unconventional gas and oil recovery and in-situ mining in mineral processing. However, effective utilization of SCDA in such application needs much extensive research on the performance of SCDA with respect to its potential applications, particularly when considering unique issues arising in using SCDA in different ...

show abstract

Section: Potential Applications Of Soundless Chemical Demolition Agentmentioning

confidence: 99%

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

2016

View full text Add to dashboard Cite

show abstract

“…According to microseismic monitoring mapping [24] and the result of indoor core fracturing experiment [28,29], we can know that the reservoir after volume fracturing can be divided into two regions, one is the SRV and another is the un-SRV. The SRV is circular, and many fractures are developed in the SRV (Figure 1).…”

Section: Physical Model Of Volume Fracturing Vertical Wellmentioning

confidence: 99%

Pressure Analysis for Volume Fracturing Vertical Well considering Low-Velocity Non-Darcy Flow and Stress Sensitivity

Cui

Trivedi

et al. 2019

Geofluids

View full text Add to dashboard Cite

In general, there is stress sensitivity damage in tight reservoirs and fractures. Furthermore, the flow in tight reservoirs is the lowvelocity non-Darcy flow. Currently, few researches of pressure analysis for volume fracturing vertical well are conducted simultaneously considering the low-velocity non-Darcy flow and stress sensitivity. In the paper, a novel flow model of a volume fractured vertical well is proposed and solved numerically. Firstly, the threshold pressure gradient, permeability modulus, and experimental data are, respectively, utilized to characterize the low-velocity non-Darcy flow, matrix stress sensitivity, and fracture stress sensitivity. Then, a two-region composite reservoir is established to simulate the vertical well with volume fracturing. After that, the logarithm meshing method is used to discrete the composite reservoir, and the flow model is solved by the method of finite difference and IMPES. Finally, the model verification is conducted, and the effects of the low-velocity non-Darcy flow and stress sensitivity on the pressure and pressure derivative are analyzed. The six flow regimes are identified by the dimensionless pressure and pressure derivative curve. They are, respectively, the fracture linear flow regime, early transition flow regime, radial flow regime, crossflow regime, advanced transition flow regime, and boundary controlling flow regime. The stress sensitivity and threshold pressure gradient have a great effect on the dimensionless pressure and pressure derivative. With the increase of reservoir stress sensitivity, the pressure and pressure derivative are upward at the advanced transition flow and boundary controlling regimes. However, the pressure and pressure derivative are downward at the advanced transition flow and boundary controlling regimes when the fracture sensitivity increases. An increase in the threshold pressure gradient results in a high dimensionless pressure and pressure derivative. This work reveals the effects of low-velocity non-Darcy flow and stress sensitivity on pressure and provides a more accurate reference for reservoir engineers in pressure analysis when developing a tight reservoir by using the volume fracturing vertical well.

show abstract

“…During fracturing in the wells of perforation completion, the dual-wing fracture propagating along the maximum principal stress is always formed, and the fracture network is not likely to occur [1][2][3][4]. Moreover, when not being distributed along the maximum principal stress, the remaining oil is not able to be connected by the conventional dual-wing fracture, significantly reducing the effect of stimulation [5].…”

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

A new method for evaluation of fracture network formation capacity of rock

Cited by 156 publications

References 16 publications

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

Pressure Analysis for Volume Fracturing Vertical Well considering Low-Velocity Non-Darcy Flow and Stress Sensitivity

Research and Application of Radial Borehole Fracturing Based on Numerical Simulation

Contact Info

Product

Resources

About