The Mechanical Behaviour during Multiple Injections and its Influence on Fracture Network
- Li-Feng Yang, Yu-Zhang Liu, Yun-Hong Ding, Yong-Hui Wang, Xiao-Sen Shang
- Corresponding Author
- Li-Feng Yang
Available Online December 2016.
- https://doi.org/10.2991/mme-16.2017.2How to use a DOI?
- Multiple Injections, Fracturing, Shale gas, Fracture network.
- Many cases show that multiple injections fracturing serves as an effective method to increase the probability of creating complex fracture network for shale gas reservoirs. However, its mechanism is unclear. This paper, therefore, intends to use numerical simulation and theoretical models to explore this mechanism. Results indicate that the liquid fluid loss and friction along fractures act as catalysts to a large pressure drop between the initiation of fractures and the fractures tip during injection. But friction disappears when this injection terminates, and the fluid pressure decreases at the debut of fractures and increases at the fractures tips. Then the stress field changes synchronically. The probability of the extension and reorientation of fracture tip and the initiation and reorientation of weak point on the fracture surface may be multiplied. During the re-injection after a period of shut-in, the opened factures or weak points can easily propagate new fractures and does not need to overcome the resistance of the tensile strength or cohesion. Then larger volume of fracture network and more fractures can be created by multiple injections. Micro-seismic monitoring results verify the validity of the theoretical analysis and effectiveness of the method of multiple injections fracturing.
- Open Access
- This is an open access article distributed under the CC BY-NC license.
Cite this article
TY - CONF AU - Li-Feng Yang AU - Yu-Zhang Liu AU - Yun-Hong Ding AU - Yong-Hui Wang AU - Xiao-Sen Shang PY - 2016/12 DA - 2016/12 TI - The Mechanical Behaviour during Multiple Injections and its Influence on Fracture Network BT - 3rd Annual International Conference on Mechanics and Mechanical Engineering (MME 2016) PB - Atlantis Press SN - 2352-5401 UR - https://doi.org/10.2991/mme-16.2017.2 DO - https://doi.org/10.2991/mme-16.2017.2 ID - Yang2016/12 ER -