层理影响下裂缝三维垂向扩展模式数值模拟
Numerical Simulation of Three-Dimensional Vertical Fracture Propagation Model under the Influence of Bedding
王博 1王乾任 1周航 2张荔 1解子祺1
作者信息
- 1. 中国石油大学(北京)克拉玛依校区,新疆克拉玛依 834000
- 2. 中国石油大学(北京)非常规油气科学技术研究院,北京昌平 102249
- 折叠
摘要
新疆某区块储层具有非均质性强、天然层理面发育和应力分布不均匀等特点,含层理面储层在复杂应力条件下裂缝垂向扩展模式显著影响穿层压裂效果.基于有限元方法和内聚力模型,建立了含层理面的三维流固全耦合数值模型,系统研究了不同应力组合和层理面影响下水力裂缝垂向扩展形态,明确了含层理储层裂缝穿层扩展模式,形成了复杂应力组合下裂缝穿层形态预测图版.模型模拟结果与已发表物模实验结果一致,验证了模型的可靠性.研究结果表明:垂向应力越小,裂缝越容易激活层理面,当垂向应力小于18 MPa时,裂缝沿着层理面扩展;水平应力差越大,裂缝受到层理面的阻碍作用越大,水平应力差大于3 MPa时,裂缝更容易被层理面捕获而沿着层理面扩展;层理面抗拉强度越大,裂缝更倾向于贯穿层理面扩展.研究结果可为层状储层穿层压裂设计提供理论指导.
Abstract
The reservoirs at a block of Xinjiang Oilfield have the characteristics of high heterogeneity,and uneven natural bedding plane development and stress distribution.The vertical fracture propagation mode of such reservoirs with bedding planes under com-plex stresses has an impact on the layer-penetrating fracturing effect.Based on the finite element method and cohesive zone model,a three-dimensional fluid-solid fully coupled numerical model with bedding planes has been established.The vertical propagation pat-terns of hydraulic fractures under the influence of different stress conditions and bedding planes were studied.the layer-penetrating fracture propagation mode of reservoirs with beddings was also clarified,forming a prediction diagram of fracture penetrating patterns under complex stresses.The model's simulation results are consistent with the published results of physical modeling experiments,validating the model's reliability.The research results show that the smaller the vertical stresses,the easier the fractures activated along the bedding planes.When the vertical stresses are less than 18 MPa,the fractures propagate along the bedding planes.The great-er the horizontal stress difference,the greater the barrier effect applied on the fractures by the bedding planes.When the horizontal stress difference is greater than 3 MPa,the fractures are more easily captured by the bedding planes and propagate along the bedding planes.The greater the tensile strength of the bedding planes,the more likely the fractures are to propagate through the bedding planes.The research results will provide theoretical guidance for layer-penetrating fracturing design of layered reservoirs.
关键词
非均质储层/水力压裂/裂缝/垂向扩展/层理面/数值模拟Key words
heterogeneous reservoir/hydraulic fracturing/fracture/vertical propagation/bedding plane/numerical simulation引用本文复制引用
基金项目
国家自然科学基金(52104011)
国家自然科学基金(52374057)
出版年
2024
NETL
NSTL
万方数据