Wenming Jiang

Pipeline infrastructure constitutes the primary transportation system within the oil and gas industry, where operational safety is critically dependent on advanced in-line inspection technologies. This study presents a comprehensive analysis of eddy current testing (ECT) applications for pipeline integrity assessment. The fundamental principles of ECT are first elucidated, followed by a systematic comparative evaluation of five key ECT methodologies: conventional, multi-frequency, remote field, pulsed, and array eddy current techniques. The analysis examines their detection mechanisms, technical specifications, comparative advantages, and current developmental trajectories, with particular emphasis on future technological evolution. Subsequently, integrating global pipeline infrastructure development trends and market requirements, representative designs of pipeline inspection tools are detailed and we review relevant industry applications. Finally, persistent challenges in ECT applications are identified, particularly regarding adaptability to complex operational environments, quantification accuracy for micro-scale defects, and predictive capability for defect progression. This study proposes that future ECT equipment development should prioritize multi-modal integration, miniaturization, and intelligent analysis to enable comprehensive pipeline safety management throughout the entire asset lifecycle.

This study tackles the challenge of treating high-oil (≥90 mg/L) and high-salinity (Cl⁻ ≥ 6900 mg/L) oilfield-produced water for green hydrogen production. An integrated technology combining electrochemical cascade purification (EDCF: electro-demulsification–coagulation–flotation) with alkaline water electrolysis is developed. The EDCF process effectively reduces oil, suspended solids, and turbidity to 2 in 6 M KOH at 85 °C, with 96.58% H₂ purity. Crucially, separate anolyte/catholyte (0.5/6 M KOH) mitigates Cl⁻ corrosion, enabling stable 240 h operation (96.66% ± 0.5% H₂ purity) in a duplex steel electrolyzer. The work establishes comprehensive boundary conditions for scalable hydrogen production from treated produced water.

Air flotation separation technology has emerged as one of the core techniques for oily wastewater treatment in oilfields, owing to its advantages of high throughput, high separation efficiency, and short retention time. Originally applied in mineral processing, this technology was first introduced to oilfield produced water treatment by Shell in 1960. With the optimization of microbubble generators, advances in microbubble generation technology—characterized by small size, high stability, and uniformity—have further expanded its applications across various wastewater treatment scenarios. To optimize the separation performance of a horizontal compact closed-loop cyclonic air flotation unit, this study employs CFD numerical simulation to investigate two key aspects: First, for the flotation zone, the effects of structural parameters (deflector height, inclination angle) and operational parameters (gas–oil ratio, bubble size, inlet velocity) on flow patterns and gas distribution were systematically examined. Device performance was evaluated using metrics such as gas–oil ratio distribution curves and flow field characteristics, enabling the identification of operating conditions for stratified flow formation and the determination of optimal deflector structural parameters. Second, based on the Eulerian multiphase flow model and RSM turbulence model, a numerical simulation model for the oil–gas–water three-phase flow field was established. The influences of key parameters (bubble size, throughput, gas–oil ratio) on oil–water separation efficiency were investigated, and the optimal operating conditions for the unit were determined by integrating oil-phase/gas-phase distribution characteristics with oil removal rate data. This research provides theoretical support for the structural optimization and engineering application of horizontal compact closed-loop cyclonic flotation units.

Supersonic separation technology is a natural gas treatment technology with easy processing, low investment, low energy consumption, no need to add chemicals, and environmental protection. However, supersonic separation technology is immature. Furthermore, the accuracy of existing nucleation theories for the droplet nucleation process in the supersonic nozzle remains unclear, because they do not consider the effect of swirling motion. The nucleation and condensation processes of water vapor were investigated via molecular dynamics (MD) simulations in this study, and the effects of cooling temperature, axial velocity, and tangential velocity on swirling flow condensation characteristics were analyzed kinetically and thermodynamically at the microscopic level. It is found that at lower cooling temperatures and higher axial velocities, the induction phase of the water vapor condensation process is shortened, the nucleation rate increases, and nucleation occurs more easily. When the axial velocity increases from 200 to 400 m/s, the nucleation rate increases about twice. When the cooling temperature increased from 313 to 353 K, the nucleation rate decreased by 57.7%. However, changes in tangentials have little effect on water vapor swirling flow condensation characteristics.

The properties of aggregates significantly affect the demulsification efficiency within the electrocoagulation reactor. This paper aims to explore aggregate properties including the particle size, strength factor (F-s), and recovery factor (F-r). The experiments were carried out using aluminum-aluminum electrodes. The experimental results indicate that breakage time did not change F-s much but was positively correlated with F-r. When the current was increased from 0.75 A to 1.0 A, F-s experienced a decrease of 12.42%, while F-r exhibited an increase of 19.38%. In comparison to pH 9.0, both F-s and F-r demonstrated an increase at pH levels of 2.0 and 10.0. The size of aggregates significantly decreases under rocking conditions simulating offshore environments, while the oil removal rate does not change much. This phenomenon can be attributed to the fact that different initial mean particle sizes have different F-s and F-r. The aggregates |F-s-F-r| were positively correlated with the initial average particle size of the electroflocculated aggregates. The present study offers a crucial theoretical foundation for the growth and regulation of aggregates formed during electrocoagulation treatment of oil spills on the sea surface.

The effect of the supersonic separator on the condensation characteristics and fluid separation efficiency is not clear, and the structure of the liquid separation device still has room for optimization. Therefore, based on the rear-swirl type supersonic separator, three kinds of drainage ports and three kinds of liquid collection tank structures were proposed. The supersonic flow and separation process was studied numerically under nine different combination structures. The influence of the drainage port’s length and width and the inclination of the liquid collection tank on the liquefaction and separation process were analyzed. The separation trajectory of condensation droplets and the influence of particle size on the separation efficiency were clarified. The results show that the liquid separation device structure of the Em-Attached wall type can take condensation and separation efficiency into account, and its separation effect is the best. The optimal size of the key components was obtained: the length of the drainage port is 150 mm, the width of the drainage port is 3 mm, and the inclination of the liquid collection tank is 14 °. The particle size of the condensation droplets is in the range of 2 μm to 6 μm.