Pore structure and fractal characteristics of the marine shale of the longmaxi formation in the changning area, Southern Sichuan Basin, China

Frontiers in Earth Science, Journal Year: 2022, Volume and Issue: 10

Published: Sept. 14, 2022

The pore structure is an important factor affecting reservoir capacity and shale gas production. of the Longmaxi Formation in Changning area, Southern Sichuan Basin, highly heterogeneous has a complex structure. To quantitatively characterize shale’s influencing factors, based on whole rock X-ray diffraction, argon ion polishing electron microscopy observations, low-temperature nitrogen adsorption-desorption experiments, characteristics are studied by using Frenkel-Halsey-Hill (FHH) model. research reveals following: 1) pores mainly include organic pores, intergranular dissolution microfractures. size micro-mesoporous. Both ink bottle-type semiclosed slit-type with good openness exist, but observed. 2) self-similarity, conforms to fractal law, shows double characteristics. Taking relative pressure 0.45 (P/P 0 = 0.45) as boundary, surface dimension D sf structural st defined. between 2.3215 2.6117, 2.8424 2.9016. micropores mesopores more complex. 3) mineral components matter have obvious control over shale, samples from different wells show certain differences. positive correlation quartz content negative clay minerals. higher total carbon is, degree thermal evolution, larger dimension. results guiding significance for characterization tight rocks.

Language: Английский

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Complicated Fault Characterization and Its Influence on Shale Gas Preservation in the Southern Margin of the Sichuan Basin, China

Lithosphere, Journal Year: 2022, Volume and Issue: 2022(Special 12)

Published: June 1, 2022

Abstract The southern margin of the Sichuan Basin is characterized by strong structural deformation, complex fault structure styles and scales, multistaged geological evolution stages, which together have created various shale gas preservation conditions. Taking Jianwu (JW)–Luochang (LC)–Shuanglong (SL) synclines as an example, development characteristics Longmaxi Formation were studied based on fine seismic interpretation microscopic tests (rock acoustic emission experiments fracture-filling inclusion tests), effects stage, class scale, fracture degree conditions analysed. Basement-involved faults, detachment intraformational microfaults are mainly developed from southeast to northwest. These types affected JW Syncline in southeastern part, where faults bottom Cambrian Wufeng–Longmaxi Permian (Triassic). SL-LC region northwestern part dominated This NE-trending main control supplemented NW-trending, approximately EW-trending, SN-trending, other small-scale regulating faults. Fault can be divided into three corresponding early, middle, late Himalayan tectonic movements. In early a few EW-trending had little impact preservation. intermediate large number large-scale significantly impacted with high-filling degree, weak upwards penetration, relevant fractures, favourable for western northern parts I II low-filling large-scale, penetration related unfavourable During SN- NW-trending strike-slip reverse developed, shear zones formed near producing research has clarified characterization method stages established influence preservation, important reference value exploration evaluation reserves regions.

Language: Английский

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Geological Characteristics of Deep Shale Gas and Their Effects on Shale Fracability in the Wufeng-Longmaxi Formations of the Southern Sichuan Basin, China

Lithosphere, Journal Year: 2023, Volume and Issue: 2023(1)

Published: April 3, 2023

Abstract The deep shale gas reservoirs of the Wufeng-Longmaxi Formations in southern Sichuan Basin have strong heterogeneity and complex geological characteristics, resulting a poor fracturing effect low vertical production. Based on whole-rock X-ray diffraction analysis, scanning electron microscopy, gas-bearing experiments, rock mechanical parameter tests well logging elemental data, sedimentary environment, characteristics this are analyzed, fracability is evaluated. (1) type organic matter affected by factors such as sea level change, hydrodynamics, reducing environmental conditions, algae bioenrichment, tectonic stability, contents Type I II kerogens lowermost reservoir high. (2) pores between biogenic siliceous minerals (the framework) numerous provide space for occurrence gas. High-quality high brittle mineral content, Young’s modulus, Poisson’s ratio, an appropriate pressure, small net stress difference, fracability. (3) Multicluster perforation, temporary plugging near wellbore, multistage can be used Wufeng Formation-Longmaxi Formation, increasing near-wellbore hydraulic fracture complexity improving effect.

Language: Английский

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Determination of the main parameters of the mechanisms of a two-stage compressor and their kinematic analysis

AIP conference proceedings, Journal Year: 2023, Volume and Issue: 2789, P. 040001 - 040001

Published: Jan. 1, 2023

Language: Английский

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Experimental study of hydraulic equipment operation process

E3S Web of Conferences, Journal Year: 2021, Volume and Issue: 264, P. 02026 - 02026

Published: Jan. 1, 2021

Relevance. When the hydraulic fluid is operated for several cycles, impact on performance and longevity greatly increased. So, there are ways to fix this problem. To increase efficiency of system, it necessary study working processes, systems quick-change equipment machine with a lawn k shp made as whole, attached suspension device. The complexity these processes lies in fact that they allow experimental research verification results using mathematical models. Aim. purpose dissertation effect forces acting system when excavating multipurpose substantiate parameters by assessing power use efficiency. Methods. Checking suitability during earthworks, well model. In case, we studied single-bucket excavator, device universal machine. Results. theoretical work performed has been verified confirmation operation designed earth dozer equipment. installation based TTZ-80 possible carry out most energy-intensive workflow, determining energy indicators excavation leveling. Conclusion. Comprehensive tests conclude characteristics developed design engine base - TTZ-80.10 KM-1 tractor, overcome resistance encountered technological operations

Language: Английский

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Geometric characteristics of diverting fractures for multi-stage dynamic temporary plugging and diverting fracturing in fractured reservoir

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(3)

Published: March 1, 2024

Temporary plugging and diverting fracturing (TPDF) technology constitutes a pivotal stimulation methodology in the advancement of unconventional resources, given its efficacy establishing communication with natural fractures (NFs). Presently, comprehension TPDF is primarily confined to laboratory-scale experiments, notable dearth accurate knowledge regarding law geometric characteristics at field scale. This study introduces hydro-mechanical-damage model for hydraulic fracture (HF) propagation, developed through derivation refinement phase method. The integrates dynamic flow distribution process among multi-perforation clusters under stress interference, alongside construction transportation temporary agent TPDF. Subsequently, coupled encompassing multi-cluster multi-stage established using finite element Utilizing this model, an exploration fracture's opening propagation mechanisms, as well impact reservoir factors on characteristics, conducted results show that has high accuracy, first time, it realistically simulates gradual increase decrease pressure after plugging. affected by interference from initial HF (ini HF), NF, horizontal difference. energy required open NFs form higher than cross plugging, there strong positive correlation between rise approach angle use multi-scale agents can promote more uniform fractures. When NF near 60°, larger control volume. interaction are great significance position According pattern fractures, they be divided into five categories. alleviate directional HFs caused induction. alleviating effect not only controlled mode but also related density. distance formed inferior will about 50% farther compared superior fracture. mainly interfered same perforation cluster early stage different middle late stages.

Language: Английский

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Effects of Fracture Formation Stage on Shale Gas Preservation Conditions and Enrichment in Complex Structural Areas in the Southern Sichuan Basin, China

Frontiers in Earth Science, Journal Year: 2022, Volume and Issue: 10

Published: May 24, 2022

Fractures have significantly impacted the preservation, enrichment, and productivity of shale gas in Longmaxi Formation complex structural area southern Sichuan Basin. Based on outcrop, core, imaging logging, inclusion analysis, acoustic emission experiments, burial thermal evolution history data, formation stage, preservation conditions fractures were comprehensively studied. Shear are main features tectonic origin characterized by small widths, wide spacing, high filling degrees. The can be divided into three groups terms their stage. first-stage formed middle-late period Yanshanian movement (86.2–68.5 Ma), when palaeotectonic stress was 68.33–71.82 MPa; homogenization temperature fluid inclusions corresponding fracture fillings is 150–178°C. second-stage at end -early Himalayan (68.5–35.2 85.2–100.5 123–148°C. third-stage during (35.2–0 55.6–63.8 scarce these fractures, but measured 90–110°C. Shale affected maximum horizontal crustal stress, fault scale, depth, pressure coefficient, etc. Three types favourable identified. Type I target low slope middle syncline, which occurs more than 2.0 km from fault. research results guiding significance for evaluation deep study similar areas.

Language: Английский

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Simulation of fracture control during temporary plugging at fracture openings in deep and ultra-deep shale-gas horizontal wells

Natural Gas Industry B, Journal Year: 2022, Volume and Issue: 9(5), P. 487 - 496

Published: Oct. 1, 2022

Language: Английский

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Numerical Modeling of Fracture Propagation during Temporary Plugging and Diverting Fracturing

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

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Characterization of diabase core anisotropy: Integrating ultrasonic measurements and digital rock physics

Journal of Applied Geophysics, Journal Year: 2025, Volume and Issue: unknown, P. 105698 - 105698

Published: March 1, 2025

Language: Английский

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