Propagation pattern of cracks around a shale borehole via the cohesive element method

Journal of Petroleum Exploration and Production Technology, Journal Year: 2025, Volume and Issue: 15(2)

Published: Jan. 18, 2025

Shale gas is a cutting edge energy source for development, and reserves are abundant. However, shale microcracks develop tend to form macroscopic fractures during drilling, which can cause severe wellbore instability. Therefore, in combination with rock mechanics theory fracture theory, the cohesive element method adopted establish numerical model differential crack propagation due bottomhole pressure on basis of B-K criterion. The pattern cracks around simulated, influences mechanical parameters, initial length, direction distribution, minimum horizontal stress analyzed. research results indicate that larger Young's modulus is, easier it propagate. Poisson's ratio has large influence widening, but its effect length weak. angle between maximum more difficult greater weak propagation.

Language: Английский

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Poly(Vinyl Alcohol)-Doped Surface-Modified Graphene Oxide/Cellulose Porous Aerogel for Oil-Based Drilling Fluid Plugging

ACS Omega, Journal Year: 2025, Volume and Issue: 10(4), P. 3665 - 3675

Published: Jan. 22, 2025

To counter the threat to wellbore stability in shale formations posed by filtrate invasion and pressure transmission of oil-based drilling fluids (OBDFs), it is critical develop a material that can effectively seal micron-scale fractures. Graphene oxide was surface-modified cross-linking entanglement strategy used prepare tough carbon aerogels (HPGA2) with porous structure, HPGA2 were characterized Fourier transform infrared, Raman, thermogravimetric analysis, X-ray photoelectron spectroscopy, diffraction. Scanning electron microscopy, SDM, Brunauer–Emmett–Teller confirmed pores are mainly micro- mesopores less than 10 nm size, which results swift absorption oil HPGA2. SLS found have 90% particles below 35 μm, suitable for plugging microcracks formation. The impact on rheological characteristics assessed through performance test an emulsion breaking voltage test, respectively. evaluated via medium-pressure filtration high-temperature high-pressure simulated microfracture experiment. experimental show inclusion has minimal OBDFs; when added at level 2%, demonstrates outstanding compatibility OBDFs substantially cut down loss both standard high-temperature, environments; experiment microcrack plugging, pressure-bearing capacity fluid 2 wt % about times higher original fluid, while permeability decreased from 92 9%. This paper introduces technique fabricating composite exhibits superior sealing capabilities, providing way solve instability caused during drilling.

Language: Английский

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Thermophysical-mechanical behaviors of hot dry granite subjected to thermal shock cycles and dynamic loadings

Journal of Rock Mechanics and Geotechnical Engineering, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 1, 2024

Language: Английский

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Development and Characterization of the Shale Stratum Well Wall Stabilized with Nanosomal Sealing Agent

Polymers, Journal Year: 2024, Volume and Issue: 16(12), P. 1614 - 1614

Published: June 7, 2024

The development of micro cracks in shale formations can easily lead to wellbore instability caused by liquid phase invasion. In order effectively seal the micropores, surface treatment nano-SiO

Language: Английский

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