Open Access

ARTICLE

Study on the Impact of Massive Refracturing on the Fracture Network in Tight Oil Reservoir Horizontal Wells

Jianchao Shi^1,2, Yanan Zhang³, Wantao Liu^1,2, Yuliang Su^3,*, Jian Shi^1,2

1 Exploration and Development Research Institute, Changqing Oilfield Company, Xi’an, 710018, China
2 National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields, Xi’an, 710018, China
3 Key Laboratory of Unconventional Oil and Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao, 266580, China

* Corresponding Author: Yuliang Su. Email:

(This article belongs to the Special Issue: Solid, Fluid, and Thermal Dynamics in the Development of Unconventional Resources )

Fluid Dynamics & Materials Processing 2024, 20(5), 1147-1163. https://doi.org/10.32604/fdmp.2023.044500

Received 31 July 2023; Accepted 14 November 2023; Issue published 07 June 2024

Abstract

Class III tight oil reservoirs have low porosity and permeability, which are often responsible for low production rates and limited recovery. Extensive repeated fracturing is a well-known technique to fix some of these issues. With such methods, existing fractures are refractured, and/or new fractures are created to facilitate communication with natural fractures. This study explored how different refracturing methods affect horizontal well fracture networks, with a special focus on morphology and related fluid flow changes. In particular, the study relied on the unconventional fracture model (UFM). The evolution of fracture morphology and flow field after the initial fracturing were analyzed accordingly. The simulation results indicated that increased formation energy and reduced reservoir stress differences can promote fracture expansion. It was shown that the length of the fracture network, the width of the fracture network, and the complexity of the fracture can be improved, the oil drainage area can be increased, the distance of oil and gas seepage can be reduced, and the production of a single well can be significantly increased.

---

Keywords

---