Coupling Simulation Model of Transient Flow in Tubing and Unsteady Seepage in Reservoir During Hydraulic Fracturing with Unstable Injection

Zhu, Guangjun; Dong, Shimin

doi:10.1007/s13369-021-05535-5

Cited by 2 publications

(1 citation statement)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nevertheless, the bidirectional coupling between the fluid in the tubing and reservoirs was not considered, and the reservoir seepage was ignored. Subsequently, although a coupling simulation model of fluid flow in the tubing and reservoirs seepage was developed, 8 the model could not simulate the initiation and propagation of hydraulic fractures. In addition, Tong et al 9 proposed the hydraulic pressure vibration method during fracturing and analyzed the fluid pressure in the wellbore using the unsteady theory.…”

Section: Introductionmentioning

confidence: 99%

Pulse injection simulation based on the coupling of transient flow in tubing and fracture propagation in reservoirs

Zhu

Dong

2022

Energy Science & Engineering

Self Cite

View full text Add to dashboard Cite

Pulse injection can reduce the maximum operating pressure at the wellhead, which is conducive to solving the operational difficulties caused by the high breakdown pressure. The new injection mode causes a transient fluid flow in the tubing, and it interacts with the initiation and propagation of hydraulic fractures. However, there is still a lack of theoretical models to consider the above factors so that its mechanism cannot be explained. In this study, the transient flow model in the tubing was first established. Subsequently, the fracture propagation model was completed based on particle flow code (PFC). Moreover, the transient flow model was embedded into the PFC simulation software via its code script FISH. Finally, their coupled simulation model was established. Based on this model, the effects of injection flow rates on the fluid pressure in the tubing and the initiation and propagation of hydraulic fractures were discussed. Furthermore, the influence of parameters in the pulse injection scheme on the maximum wellhead pressure was studied by the orthogonal design method. The results show that with the increase of the injection flow rate, the fluid pressurization rate in the tubing and the fracture propagation rate both raise, which also causes a significant increase of the maximum wellhead pressure. Compared with a stable injection mode, pulse injection can evidently reduce the maximum wellhead pressure.The influence degree of each parameter on the maximum wellhead pressure in the pulse scheme is as follows: t 2 > Δq > Δt 4 > Δt 5 > Δt 3 . The research results of this paper have guiding significance for the engineering application and parameter design of pulse injection hydraulic fracturing.

show abstract

Section: Introductionmentioning

confidence: 99%

Pulse injection simulation based on the coupling of transient flow in tubing and fracture propagation in reservoirs

Zhu

Dong

2022

Energy Science & Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore

et al. 2023

View full text Add to dashboard Cite

Fluid penetration into the rock during hydraulic fracturing has been an essential issue in studying the mechanism of fracture initiation, especially the seepage force caused by fluid penetration, which has an important effect on the fracture initiation mechanism around a wellbore. However, in previous studies, the effect of seepage force under unsteady seepage on the fracture initiation mechanism was not considered. In this study, a new seepage model that can predict the variations of pore pressure and seepage force with time around a vertical wellbore for hydraulic fracturing was established by using the method of separation of variables and the Bessel function theory. Then, based on the proposed seepage model, a new circumferential stress calculation model considering the time-dependent effect of seepage force was established. The accuracy and applicability of the seepage model and the mechanical model were verified by comparison with numerical, analytical and experimental results. The time-dependent effect of seepage force on fracture initiation under unsteady seepage was analyzed and discussed. The results show that when the wellbore pressure is constant, the circumferential stress induced by seepage force increases over time, and the possibility of fracture initiation also increases. The higher the hydraulic conductivity, the lower the fluid viscosity and the shorter the time required for tensile failure during hydraulic fracturing. In particular, when the tensile strength of rock is lower, the fracture initiation may occur within the rock mass rather than on the wellbore wall. This study is promising to provide a theoretical basis and practical guidance for further research on fracture initiation in the future.

show abstract

Coupling Simulation Model of Transient Flow in Tubing and Unsteady Seepage in Reservoir During Hydraulic Fracturing with Unstable Injection

Cited by 2 publications

References 24 publications

Pulse injection simulation based on the coupling of transient flow in tubing and fracture propagation in reservoirs

Pulse injection simulation based on the coupling of transient flow in tubing and fracture propagation in reservoirs

Time-Dependent Effect of Seepage Force on Initiation of Hydraulic Fracture around a Vertical Wellbore

Contact Info

Product

Resources

About