Research Article
Application of Liquid Flow Cavitation Reservoir Micro Modification Technology in Improving Water Drive Effect in Poor Reservoirs of Bohai A Oilfield
Chai Shichao*,
Li Xiang,
Zheng Jianjun,
Li Enlin,
Ren Yuxuan
Issue:
Volume 13, Issue 2, June 2025
Pages:
47-53
Received:
9 March 2025
Accepted:
8 April 2025
Published:
14 April 2025
Abstract: B9~B8H are the corresponding well groups for injection and production in Bohai River facies A oilfield. There are poor reservoir bands about 100~300m away from the injection well B9, with poor connectivity between oil and water wells. The wellhead pressure of the injection well rises rapidly, resulting in long-term under injection. The water drive effect of the production well B8H is poor, making it a low yield and low efficiency well. Conventional measures such as acidification, microfracturing, and pressurized water injection have limited treatment radii, and fracturing also poses a risk of injection water breaking through along the fracture zone. Therefore, it is necessary to find new process measures that can meet the requirements of a sufficiently large treatment radius and micro modification of poor reservoir bands. The liquid flow cavitation technology achieves the goal of reservoir micro transformation by improving natural micro cracks, directing pore throat channels, and adding new micro cracks, and can meet the requirements of large processing radius. After the implementation of liquid flow cavitation in well B9, the production situation at both ends of the injection and production has improved, and the reservoir properties, connectivity, permeability, and water drive effect between injection and production wells have been significantly improved. The successful application of this technology has provided reliable process measures for solving the problems of poor reservoir bands, weak connectivity between injection and production wells, and poor water drive effects in Bohai Oilfield.
Abstract: B9~B8H are the corresponding well groups for injection and production in Bohai River facies A oilfield. There are poor reservoir bands about 100~300m away from the injection well B9, with poor connectivity between oil and water wells. The wellhead pressure of the injection well rises rapidly, resulting in long-term under injection. The water drive ...
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Research Article
Numerical Simulation of Tee Pipe Failure Under Mixed Mode-I/III Loading
Issue:
Volume 13, Issue 2, June 2025
Pages:
54-66
Received:
8 May 2025
Accepted:
3 June 2025
Published:
11 June 2025
DOI:
10.11648/j.ajee.20251302.12
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Abstract: This study probes the brittle fracture mechanisms of an S32205 duplex stainless steel tee pipe (DN300×10 mm) subjected to mixed-mode I/III loading under internal pressures spanning 10 to 30 MPa, leveraging advanced finite element analysis to address reliability concerns in high-pressure oil and gas transport systems. Drawing on recent fracture mechanics insights, an energy-driven three-dimensional framework was formulated to forecast crack propagation, emphasizing metallurgical flaws such as micro-cracks and σ-phase precipitates across varied pressure conditions. By partitioning the crack tip into discrete zones, the model calculates energy release rates and stress intensity factors (KI, KIII, Keff) for crack morphologies, including trifurcation, symmetric branching, and lateral bifurcation. Findings reveal that Mode I stresses maximize at the crack’s deepest point (90°), with KI and Keff exhibiting nonlinear escalation as pressure, crack depth-to-length ratio (a/c), and crack half-length (c) increase, portending elevated risks of unstable crack advancement. Mode III stresses, peaking at 60° and 120°, induce localized tearing, with KIII displaying marked sensitivity to pressure fluctuations. Pressure-amplified stress concentrations at the branch neck and main pipe abdomen corroborate chevron fracture patterns observed in duplex stainless steel tests, affirming the model’s fidelity. The results elucidate the synergistic degradation of fracture toughness by micro-cracks, σ-phase, and pressure-induced stresses, precipitating brittle failure. Heat treatment at 1030°C with water quenching to mitigate σ-phase and periodic ultrasonic inspections are advocated to bolster tee pipe durability in rigorous oilfield settings.
Abstract: This study probes the brittle fracture mechanisms of an S32205 duplex stainless steel tee pipe (DN300×10 mm) subjected to mixed-mode I/III loading under internal pressures spanning 10 to 30 MPa, leveraging advanced finite element analysis to address reliability concerns in high-pressure oil and gas transport systems. Drawing on recent fracture mech...
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,
Yujun Xie*
