In order to clarify the controlling effects of tectonic activity on hydrocarbon migration efficiency in the Permian–Triassic strata of the Luzhou area, Sichuan Basin, this study takes faults as the research objective. Using 3D seismic data, tectonic evolution records, and single-well test data, we systematically analyze the geometric characteristics, activity phases, classification by grade and type, and reservoir-controlling effects of faults. The results show that a total of 843 reverse faults have been identified in the study area. The major faults are distributed in a NE-SW trend, with eight planar combination styles developed, and the main cross-sectional styles are back-thrust and “Y”-shaped types. The faults experienced four phases of tectonic activity: Caledonian, Hercynian, Indosinian, and Yanshan–Himalayan. Among these, the Indosinian phase is the key formative phase, effectively connecting the source rocks and reservoirs. The faults are classified into three grades and four categories: source-connected faults, reservoir-modifying faults, damaging faults, and source-connected and damaging faults. Migration efficiency is jointly controlled by fault grade, activity phases, and the penetrated formations. Among them, third-order source-connected faults formed during the Indosinian phase exhibit the highest migration efficiency, while first-order damaging faults formed during the Yanshan phase tend to cause hydrocarbon dissipation. This study can provide a reference for hydrocarbon exploration and the prediction of favorable areas in the Luzhou area.

This paper explores the internal rock plugging rules induced by oily sludge profile control systems in oilfields. Three typical sludges including wastewater tank bottom sludge (WTBS), crude oil tank bottom sludge (CTBS) and floating scum sludge (FSS) are adopted. Combined with micro-CT scanning and digital core technology, this paper systematically investigates the pore–throat structure evolution and damage mechanism before and after sludge injection into rock cores. Key parameters such as plugging rate, average pore radius, throat radius, coordination number, shape factor, pore–throat ratio and pore–throat volume are quantitatively characterized macroscopically and microscopically, which reveal diverse damage modes and plugging mechanisms of the three sludges. The results indicate that pores of 10–50 μm are preferentially blocked by all sludges. CTBS causes the severest core damage with an average plugging rate of 79.67%, and the average coordination number decreases from 4 to 1, governed by the mechanism of adsorption diameter reduction and structural destruction. WTBS leads to uniform jamming of fine particles. Its average parameters change slightly, yet permeability declines due to broken critical throats. It follows the mechanism of uniform filling and weak adsorption with an average plugging rate of 56.75%, showing mild reservoir modification capacity. FSS causes moderate damage. Retained emulsion droplets trigger uniform slight shrinkage of pore throats under partial and overall selective filling mechanism, with an average plugging rate of 63.36% and favorable selective plugging performance. This study clarifies the inherent correlation between macroscopic damage and microscopic behaviors of oily sludge, offering microscopic theoretical references for differentiated management of sludge reinjection and oil displacement with composite sludge profile control agents.

Pore-scale heterogeneity is an important consideration in the evaluation of heavy-oil reservoirs. The aim of this study was to reconstruct CT-based digital cores of four plug samples, characterize their pore structures, and analyze single-phase flow behavior, in order to clarify how pore geometry and segmentation control the computed porosity and permeability. Four plug samples (two glutenite and two pebbly sandstone) from the Guantao Formation of the D84 Block, Liaohe Depression, were investigated using X-ray micro-computed tomography (micro-CT) with an isotropic voxel size of 9.37 μm. Three-dimensional digital cores were reconstructed through image preprocessing and interactive threshold segmentation. CT-derived porosity, volume-weighted equivalent-diameter distributions of labeled pore objects, and axial porosity variability were analyzed. Single-phase flow simulations were performed in PerGeos to estimate permeability and visualize streamline and pressure distributions. The CT-derived porosities ranged from 27.37% to 32.92%, whereas the simulated permeabilities ranged from 1009 to 1477 mD. ZS-1 exhibited the lowest CT-derived porosity but the highest simulated permeability, indicating that bulk porosity alone did not fully account for variations in simulated flow behavior among the four samples. The simulated permeabilities were lower than the laboratory-measured values, with relative differences ranging from 10.6% to 52.4%. These differences highlight the influence of image resolution, segmentation, and differences between numerical and experimental conditions on image-based permeability estimation. The study provides a sample-scale characterization of pore structures and single-phase flow behavior in the investigated reservoir material.