基于FEMM的径向井压裂裂缝扩展模拟研究

doi:10.13809/j.cnki.cn32-1825/te.2020.01.016

摘要/Abstract

摘要：

径向井可用于引导水力压裂裂缝定向扩展,达到沟通非常规储层中的天然裂隙或溶洞,提高油气资源采收率的目的。径向井压裂技术已经在低渗透、浅埋藏油气田中得到了初步的应用和发展,但其机理仍不明确。因此,介绍了FEMM（Finite Element-Meshfree Method）的基本原理,并基于FEMM和现场数据建立了不同布井角度的径向井水力压裂模型,研究了不同方位角对径向井压裂裂缝扩展的影响规律。结果表明：利用FEMM验证了径向井对水力裂缝的扩展有一定的引导作用;水力裂缝首先沿着径向井方向扩展,扩展一段距离后沿着最大水平主应力方向扩展;径向井与最大水平主应力的夹角越大,径向井引导水力裂缝扩展的距离越短,径向井对裂缝的引导作用越小。研究成果对径向井压裂技术的应用具有一定的意义。

关键词: 径向井, 水力压裂, FEMM, 引导扩展, 裂缝路径

Abstract:

Radial wells can be used to guide the propagation of hydraulic fractures in order to connect the natural fractures or caves in unconventional reservoirs and improve the recovery of oil and gas resources. Fracturing technology of radial wells has been preliminarily applied and developed in low permeability and shallow reservoirs, but its mechanism is still not very clear. Therefore, the basic principle of FEMM（Finite Element-Meshfree Method） is introduced. Besides, based on the FEMM and the field data, the radial well fracturing model with different well angles is established, and the effect of different azimuth angles on fracture propagation of radial well fracturing is studied. The results show that by using FEMM, it can be verified that radial wells play a guiding role in hydraulic fracturing. In addition, the hydraulic fracture firstly propagates along the direction of radial wells. After extending a certain distance, it turns to the direction of maximum horizontal stress. The bigger the angle between the radial wells and the horizontal maximum principal stress, and the shorter the length of fracture extending along the radial wells, the weaker the guiding ability of radial wells will be. The research results contribute to the application of radial well fracturing technology.

Key words: radial well, hydraulic fracturing, FEMM, orientated propagation, fracture path

中图分类号:

TE357

张耀峰,邵祖亮,王涛,伯音. 基于FEMM的径向井压裂裂缝扩展模拟研究[J]. 油气藏评价与开发, 2020, 10(1): 102-107.

ZHANG Yaofeng,SHAO Zuliang,WANG Tao,BO Yin. Research on fracture propagation of radial well fracturing based on finite element-meshfree method[J]. Reservoir Evaluation and Development, 2020, 10(1): 102-107.

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储层尺寸/ m	井筒直径/m	径向井长度/m	径向井直径/m	岩石泊松比	岩石孔隙度/%
40×40×2	0.139 7	20	0.05	0.25	16
岩石渗透率/10^-3 μm²	岩石杨氏模量/GPa	垂向地应力/MPa	最大水平主应力/MPa	最小水平主应力/MPa	泵注压力/MPa
30	13	45	41	36	41