当前位置: X-MOL 学术Solid Earth › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Bilinear pressure diffusion and termination of bilinear flow in a vertically fractured well injecting at constant pressure
Solid Earth ( IF 3.4 ) Pub Date : 2020-07-28 , DOI: 10.5194/se-11-1423-2020
Patricio-Ignacio Pérez Donoso , Adrián-Enrique Ortiz Rojas , Ernesto Meneses Rioseco

This work studies intensively the flow in fractures with finite hydraulic conductivity intersected by a well injecting or producing at constant pressure, either during an injection or production well test or the operation of a production well. Previous investigations showed that for a certain time the reciprocal of flow rate is proportional to the fourth root of time, which is characteristic of the flow regime known as bilinear flow. Using a 2D numerical model, we demonstrated that during the bilinear flow regime the transient propagation of isobars along the fracture is proportional to the fourth root of time. Moreover, we present relations to calculate the termination time of bilinear flow under constant injection or production well pressure as well as an expression for the bilinear hydraulic diffusivity of fractures with finite hydraulic conductivity. To determine the termination of bilinear flow regime, two different methods were used: (a) numerically measuring the transient flow rate in the well and (b) analyzing the propagation of isobars along the fracture. Numerical results show that for low dimensionless fracture conductivities the transition from bilinear flow to another flow regime (e.g., pseudo-radial flow) occurs before the pressure front reaches the fracture tip, and for high dimensionless fracture conductivities it occurs when the pressure front arrives at the fracture tip. Hence, this work complements and advances previous research on the interpretation and evaluation of well test analysis under different reservoir conditions. Our results aim to improve the understanding of the hydraulic diffusion in fractured geologic media, and as a result they can be utilized for the interpretation of hydraulic tests, for example to estimate the fracture length.

Highlights.
  • The reciprocal of flow rate is proportional to the fourth root of time.
  • The migration of isobars in the fracture is proportional to the fourth root of time.
  • For low dimensionless fracture conductivities, bilinear flow ends before the pressure front reaches the fracture tip.
  • For high dimensionless fracture conductivities, bilinear flow ends when the pressure front reaches the fracture tip.
  • Isobars accelerate when they approach the fracture tip.


中文翻译:

在恒定压力下注入的垂直压裂井中的双线性压力扩散和双线性流的终止

这项工作深入研究了在注入或生产井测试期间或在生产井的操作过程中,通过有限的水力传导率将裂缝注入井或在恒定压力下生产井相交的情况。先前的研究表明,在一定时间内,流量的倒数与时间的四次方成正比,这是称为双线性流的流态的特征。使用二维数值模型,我们证明了在双线性流动状态下,等压线沿裂缝的瞬态传播与时间的四次方成正比。此外,我们给出关系来计算在恒定注入或生产井压力下双线性流的终止时间,以及具有有限的水力传导率的裂缝的双线性水力扩散率的表达式。若要确定双线性流态的终止,使用了两种不同的方法:(a)数值测量井中的瞬变流量,以及(b)分析等压线沿裂缝的传播。数值结果表明,对于低无量纲的裂缝电导率,在压力前沿到达压裂尖端之前会发生从双线性流向另一流态(例如伪径向流)的过渡,而对于高无量纲的裂缝电导率,则在压力前沿到达时发生过渡。骨折尖端。因此,这项工作是对先前在不同储层条件下对试井分析的解释和评价的研究的补充和发展。我们的结果旨在增进对裂缝性地质介质中水力扩散的理解,因此,它们可用于解释水力试验,例如估算裂缝长度。

强调。
  • 流量的倒数与时间的四次方成正比。
  • 等压线在裂缝中的迁移与时间的四次方成正比。
  • 对于低无因次的裂缝电导率,双线性流在压力前沿到达裂缝尖端之前就结束了。
  • 对于高无量纲的裂缝电导率,当压力前沿到达裂缝尖端时,双线性流结束。
  • 等压线接近骨折尖端时会加速。
更新日期:2020-08-20
down
wechat
bug