China Petroleum Exploration ›› 2025, Vol. 30 ›› Issue (3): 165-178.DOI: 10.3969/j.issn.1672-7703.2025.03.012

Previous Articles    

Fracture propagation simulation and optimal design of ultra-deep and ultra-high pressure tight gas reservoirs in Hutubi area, Junggar Basin

Zhang Ruihan1,Xiong Zhuohang1,Zhao Chuankai2,Shi Lei2,Yan Liheng2,Chou Peng2   

  1. 1 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University; 2 Research Institute of Exploration & Development, PetroChina Xinjiang Oilfield Company
  • Online:2025-05-15 Published:2025-05-15

Abstract: The reservoirs in HT1 well area in Hutubi area are characterized by relatively great burial depth, low porosity, low permeability and tight property. The fracture propagation law is unclear given the conditions of high temperature, high pressure and well-developed natural fractures, which poses challenges for fracturing construction. In order to solve this problem, triaxial compression tests have been conducted on core samples from the target layer under high temperature and high pressure conditions to obtain rock mechanic parameters such as elastic modulus and Poisson’s ratio. Based on geology and engineering integrated method, relevant lab test data, core observation, well logging and seismic interpretation data have been used to establish a 3D geomechanical model. Finally, constrained by the geomechanical model, the fracture propagation simulation, well construction parameter optimization design, production history fitting and prediction have been analyzed in vertical wells with natural fractures developed. The study results show that: (1) The average Young’s modulus is 37.5 GPa, and the average Poisson’s ratio is 0.25. The average maximum and minimum horizontal principal stresses are 220 MPa and 180 MPa, which are much higher than those of conventional gas reservoirs (generally less than 100 MPa). (2) By setting the length of 70 m and the interval of 150 m for small-scale natural fractures, the length of hydraulic fractures has been fitted using fracture parameter inversion method based on pump off pressure drop. (3) The simulation results indicate that the optimal construction parameters include a displacement of 8 m3/min, perforation interval of 8–10 m, liquid volume of 910 m3, and sand ratio of 10%–16%. (4) After fracturing and putting into operation, the duration of steady production extends by 8 years, and the cumulative gas production increases by 16.13×108 m3, showing significant enhancement of fracturing results, which provides guidance for the development of similar blocks.

Key words: ultra-high pressure tight gas reservoir, geology and engineering integration, fracturing parameter optimization, natural fracture model, numerical simulation

CLC Number: