Adjustment of fracture network geometry during temporary plugging and diverting fracturing in deep coalbed methane reservoirs: An experimental study DOI
Yushi Zou, Ziwen Zhao, Shicheng Zhang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(12)

Published: Dec. 1, 2024

Deep coalbed methane reservoirs generally exhibit characteristics such as extremely low permeability, significant heterogeneity, high in situ stress, and dense geological discontinuities. Notably, these discontinuities cleats, bedding planes, natural fractures, mechanically weak significantly contribute to the creation of complex tortuous hydraulic fracture (HF) networks near wellbore, but impede propagation HFs far-field region. This will lead insufficient stimulated reservoir volume, thereby limiting CBM production. Under this background, a series physical simulation experiments temporary plugging diverting fracturing (TPDF) were carried out on large-size coal blocks under true triaxial stress conditions. Combining high-energy industrial computed tomography scanning technology, first, morphology sample before TPDF is divided into two modes. Then, conducted analyze behavior different Finally, mode tailored for adjusting HF network geometry deep was explored innovatively. The effects concentration particle size agent (TPA) pressure increment, location diversion during examined particular. Experimental results indicate that optimizing particle-size TPA based resulting crucial (simplifying growth wellbore while increasing complexity region) conventional (before using TPA). When created condition formation with high-dense fractures (NFs) region, small-particle-size (e.g., 70/140 mesh) optimal geometry, it can effectively plug NFs allow them continue extending toward Meanwhile, higher beneficial interval closer then causing networks. long single generated low-dense NFs, medium-particle-size 40/70 enhancing Using excessively large sizes 20/40 tends at their entrances, be reinitiated from unstimulated segment wellbore. study provide theoretical guidance scheme design reservoirs.

Language: Английский

A Genetic Particle Swarm Optimization with Policy Gradient for Hydraulic Fracturing Optimization DOI
Yunjin Wang,

Leyi Zheng,

Chen Gong

et al.

SPE Journal, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 13

Published: Dec. 1, 2024

Summary Particle swarm optimization (PSO) has been widely developed and applied as one of the important algorithms for problems because its few control parameters low complexity. However, conventional PSO problem premature convergence. Most optimized are adjusted manually, technology adaptive adjustment based on reinforcement learning (RL) is still immature. Therefore, this study proposes a new genetic (GAPSO) with policy gradient (PGGAPSO). The algorithm constructs strategy neural network an agent to dynamically output action probability distribution passes highest selection GAPSO section through designed function, thereby updating parameters. solves obtained uses individual global optimums from iterations inputs network. In addition, elite introduced enhance exploration capability PGGAPSO. Then, performance PGGAPSO was comprehensively evaluated using convergence analysis, statistical tests, Friedman rank, runtime analysis. Finally, construction parameter hydraulic fracturing. results show that due influence number samples, general in early stage iteration but shows excellent continuous iteration. For unimodal most multimodal functions, significant difference excellence. Additional processes, such (PG), resulted 7.3% increase compared GAPSO, additional computational loss acceptable relative improved accuracy. does not require objective function can be combined complex model fracturing optimize case Jimsar sag, production increased by more than 10% average.

Language: Английский

Citations

6
Numerical Modeling of Fracture Propagation during Temporary Plugging and Diverting Fracturing DOI
Haiyang Wang, Xu Su, Lu Chen

et al.

SPE Journal, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 13

Published: March 1, 2025

Summary The temporary plugging and diverting fracturing (TPDF) technique has proved to be effective in enhancing reservoir stimulation volume increasing oil gas production. However, the mechanisms influencing propagation behavior of diverted fractures under induced stress fields remain unclear. In this study, we establish a numerical simulation model considering fluid-solid coupling effects based on discrete element particle flow method for TPDF. can simulate fracture pattern evolution field around after near wellbore. results, good agreement with analytical solutions experimental data, validate correctness model. We analyzed model, investigated impact horizontal differences fluid viscosity morphology fractures. results reveal that initiates, an X-shaped strong compressive zone forms fracture. propagates along depression area (i.e., direction where is weakest). expansion causes reversal at tip initial fracture, leading its reopening. As in-situ difference increases, tensile effect gradually weakens, deflection amplitude toward increases. Fracturing seepage significantly influences fields. When low, tends deviate more Choosing high-viscosity reservoirs smaller TPDF operations conducive volume. study contribute understanding TPDF, providing theoretical support design construction schemes.

Language: Английский

Citations

0
Quantitative investigation into the relationship between the fracture geometry and the well production during near-wellbore temporary plugging and diverting fracturing DOI
Li Zhang, Lishan Yuan, Bo Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(8)

Published: Aug. 1, 2024

During near-wellbore temporary plugging and diverting fracturing (NWTDF), the old fractures can be plugged, new generated propagated along direction perpendicular to fractures. The fracture geometry after NWTDF determines stimulated volume well productivity. Studying quantitative relationship between production during is of great significance for optimization. Based on large-scale true tri-axial equipment, this work carried out propagation experiments NWTDF. experiment results confirmed feasibility forming diversion by extended finite element method obtained overall under various conditions. Moreover, based pattern geometries, a reservoir seepage model was established applied predict oil production. show that: (1) radius (FDR) significantly affects When increases from 20 m 110 m, 17.2%. (2) FDR 50 area pressure sweep region about 7.5%; when 80 degree productivity uplift not apparent. There an optimal value FDR. (3) Well with frequency, while it reaches 9, small. frequency should optimized obtain desirable volume. research provide theoretical basis optimization design

Language: Английский

Citations

2
Discrete element-based multi-cluster hydraulic fracture extension study with temporary plugging and fracturing in horizontal wells DOI
Hui Xiao, Han Zhang, Chunbing Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(6)

Published: June 1, 2024

In this paper, a two dimensional-discrete element method complex fracture extension model was developed to simulate the behavior in reservoirs during multi-cluster perforation fracturing of horizontal wells by particulate flow and considering temporary plugging conditions. The effect particle inhomogeneity on fractures, change extending characteristics before after plugging, geological construction parameters fractures under consideration conditions are investigated model. results show that: (1) middle cluster is more difficult extend than outermost due interstitial stress interference; increased nonuniformity particles aggravates interference favors shear extension. (2) Fractures expand substantially when fluid reaches 3/4 total volume; it can promote uniform increase length but formed easy be captured at ends along it, not form fractures; timing based percentage clusters with already formed, being preferred. (3) principal difference mainly affects direction extension; number uniformity

Language: Английский

Citations

1
Preparation of Double-Networked Slow-Expanding Nanomicrospheres and Evaluation of Drive Modulation Performance DOI Creative Commons

Qiaolin Zuo,

Zhenzhong Fan, Qingwang Liu

et al.

Molecules, Journal Year: 2024, Volume and Issue: 29(22), P. 5378 - 5378

Published: Nov. 14, 2024

Aiming at the problem of excessive swelling conventional microspheres for oilfield use, a novel amphiphilic polymerizable crosslinker (AE) was synthesized by quaternary ammonium modification an unstable using acrylamide, 2-acrylamido-2-methylpropanesulfonic acid as monomers, N,N'-methylene bisacrylamide stabilizing crosslinker, peroxysulfate and sodium bisulfite initiator, water solvent reversed microemulsion method. Double-networked nanomicrospheres were prepared. The preparation conditions optimized surface response method, focusing on effects initiator addition reaction temperature, total formation nanomicrospheres. samples characterized FTIR, TGA, laser particle sizer, SEM to evaluate retarded expansion performance modulation drive performance. results showed that optimal m(oil phase):m(water phase) = 3:2, stirring speed 550 r/min, crosslinking agent dosage 0.6% (based mass hereinafter same), 0.30%, temperature 45 °C, time 4 h. Compared with polymer microsphere PAM, PAE slow-expanded d 60 multiplier about 16 times, slow-expansion characteristics; blocking rate reached 98.3%, oil repulsion 73.11%, increase in recovery could be up 11.23%. In this paper, new type nanomicrosphere material is investigated realize efficient implementation field conditioning driving.

Language: Английский

Citations

0
Adjustment of fracture network geometry during temporary plugging and diverting fracturing in deep coalbed methane reservoirs: An experimental study DOI
Yushi Zou, Ziwen Zhao, Shicheng Zhang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(12)

Published: Dec. 1, 2024

Deep coalbed methane reservoirs generally exhibit characteristics such as extremely low permeability, significant heterogeneity, high in situ stress, and dense geological discontinuities. Notably, these discontinuities cleats, bedding planes, natural fractures, mechanically weak significantly contribute to the creation of complex tortuous hydraulic fracture (HF) networks near wellbore, but impede propagation HFs far-field region. This will lead insufficient stimulated reservoir volume, thereby limiting CBM production. Under this background, a series physical simulation experiments temporary plugging diverting fracturing (TPDF) were carried out on large-size coal blocks under true triaxial stress conditions. Combining high-energy industrial computed tomography scanning technology, first, morphology sample before TPDF is divided into two modes. Then, conducted analyze behavior different Finally, mode tailored for adjusting HF network geometry deep was explored innovatively. The effects concentration particle size agent (TPA) pressure increment, location diversion during examined particular. Experimental results indicate that optimizing particle-size TPA based resulting crucial (simplifying growth wellbore while increasing complexity region) conventional (before using TPA). When created condition formation with high-dense fractures (NFs) region, small-particle-size (e.g., 70/140 mesh) optimal geometry, it can effectively plug NFs allow them continue extending toward Meanwhile, higher beneficial interval closer then causing networks. long single generated low-dense NFs, medium-particle-size 40/70 enhancing Using excessively large sizes 20/40 tends at their entrances, be reinitiated from unstimulated segment wellbore. study provide theoretical guidance scheme design reservoirs.

Language: Английский

Citations

0