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Updated: Jan 18, 2026

Pore-scale Imaging and Characterization of Hydrocarbon Reservoir Rock Wettability at Subsurface Conditions Using X-ray Microtomography
Published on: October 21, 2018
Oil Well Stimulation of Dispersion-Penetration Agent and Plugging Removal Technology
Boli Yang1, Hongxing Xu1, Yue Wang1
1Changqing Downhole Technology Company, CNPC Chuanqing Drilling Engineering Co., Ltd., Xi'an 710018, China.
Abstract:
Conventional acidizing struggles to remove complex, organic-rich scales in oil wells, and while strong organic solvents can help, their high cost and safety risks limit field use. To overcome these shortcomings, we developed a low-cost, safe permeability-enhanced-dispersion (PD) technique that first loosens and disperses the scale and then applies acid for thorough cleanup. The PD fluid (DL) contains a mutually soluble fatty alcohol amide phosphate dispersant (DL-F), ethanol, a surfactant blend, and a self-generating acid. Shale-oil scale from the Chang 7 Member was compressed into cylindrical cores to mimic mixed (inorganic + organic) deposits, and a new two-step protocolPD pretreatment followed by acid floodingwas evaluated through pressure decline, weight-loss measurements, and 3-D surface morphology. Relative to direct acidizing, PD pretreatment increased acid dissolution power by ≈ 20%, doubled overall dissolution efficiency in core-flood tests, and generated multibranched etched channels that markedly improved cleanup uniformity. A field pilot on Well H1 (September 2024) confirmed laboratory findings: daily liquid production rose from 6.13 (47.7% water cut) to 11.95 m3 d-1 (42.3% water cut) 6 months after treatment, adding ∼350 t of oil. These results demonstrate that the PD-acid sequence provides a fast, deep, and even damage-removal alternative to costly organic solvents, offering a safe, economical method for routine acidizing of homogeneous reservoirs and showing strong potential for wider field adoption.

