The treatment of spent drilling fluids generated during the drilling of technological wells for uranium production represents an important engineering and environmental challenge associated with high energy consumption, significant waste generation, and the need for rational water use under arid regional conditions. Conventional phase separation methods based on gravitational settling and chemical–mechanical treatment are characterized by limited process controllability, long processing times, and increased consumption of reagents and energy. This study proposes an energy-efficient and reliable hydrodynamic technology for the treatment of spent drilling fluids based on the formation of controlled turbulent structures without the use of mechanical drives. The research object comprised spent drilling fluids (SDFs) generated during the drilling of technological wells for uranium production in the southern regions of the Republic of Kazakhstan and the Kyzylorda region. Experimental investigations were carried out using a laboratory–pilot hydrodynamic disperser with variations in velocity gradient, treatment time, flocculant dosage, and suspension flow rate. A mathematical model linking hydrodynamic process parameters with phase separation kinetics and energy characteristics was developed. Model calibration by weighted nonlinear least squares yielded a stable parameter set with 95% confidence intervals, and model validation demonstrated good agreement between calculated and experimental data (MAPE 8.4%; maximum relative error 11.8%). It was established that the use of a hydrodynamic disperser provides separation efficiency of up to 90–95% under optimal operating conditions while reducing specific energy consumption and maintaining stable repeated-cycle performance within the investigated operating window. Experimental results confirm that implementation of the hydrodynamic technology enables a reduction in sludge volume by 40–60%, recovery of up to 60–80% of process water, and a significant decrease in waste requiring transportation and disposal. The obtained results demonstrate the high environmental and resource-saving efficiency of the proposed technology and its suitability for scaling and industrial implementation at facilities drilling technological wells for uranium production. The developed hydrodynamic approach can be considered an effective engineering platform for creating energy-efficient and sustainable systems for drilling fluid treatment in regions with limited water resources and remote industrial infrastructure.

Spent water-based drilling fluids generated during technological-well drilling for uranium production are high-solid, chemically heterogeneous suspensions whose treatment is constrained by water scarcity, waste-handling requirements, reagent demand and electrical-energy consumption. This study evaluated a recirculating flow-through disperser that converts pressure-driven flow into controlled nominal velocity gradients and localized contact zones. The laboratory-pilot dataset comprised five high-solid water-based spent-fluid samples, 120 hydrodynamic treatment runs, 216 particle-size-bin observations corresponding to 12 complete distributions, nine mechanical-mixing baseline tests and ten repeated-cycle runs. The investigated range covered nominal Camp–Stein-equivalent velocity gradients of 500–1500 s⁻¹, treatment times of 60–180 s and flocculant dosages of 0–100 g/t dry solids. A 50 L batch was recirculated through a disperser with a cylindrical geometric envelope of approximately 4.75 L. The maximum separation efficiency was 94.20%. The recommended compromise condition (G = 1300 s⁻¹, τ = 150 s and 50 g/t dry solids) achieved 92.15 ± 1.81% separation efficiency, residual aqueous-phase TSS of 125.2 ± 30.0 mg/L, water recovery of 83.84 ± 0.28%, sludge-volume reduction of 59.02 ± 2.11% and wall-plug specific energy consumption of 0.1227 ± 0.0062 kWh/m³. A separate ten-cycle series yielded 0.1245 ± 0.0065 kWh/m³, consistent with the triplicate compromise-mode result. Two-factor response-surface models reproduced the measured G–τ trends and provided prediction intervals for operating-window screening within the investigated fluid class. The findings support coupled energy–separation optimization, rather than selection of the maximum nominal mixing intensity.

Spent water-based drilling fluids generated during the construction of technological wells impose substantial environmental, water-management, transportation, and energy burdens. Conventional practices, including storage in temporary pits, prolonged settling, and off-site disposal, do not enable process-water recovery and require repeated handling of suspensions with a high solids content. This study evaluates a pressure-driven cylindrical hydrodynamic disperser as the central component of a compact on-site treatment system. Unlike conventional mechanical mixers, the disperser contains no driven shaft within the active chamber. Particle–reagent contact is intensified through controlled jet shear, vortex-induced redistribution, and the motion of freely moving steel balls. Field-derived drilling fluids containing 30–40 wt.% solids, with densities of 1.12–1.17 g/cm³, pH values of 7.4–8.2, and median particle sizes of 15–50 μm, were treated at velocity gradients of 500–1500 s⁻¹ for 60–180 s using Superfloc N-300 dosages of 0–100 g/t. The optimal operating conditions were G = 1300 s⁻¹, τ = 150 s, and D = 50 g/t. Under these conditions, the separation efficiency reached 91–93%, the residual suspended-solids concentration decreased to 120–130 mg/L, process-water recovery reached 80%, sludge volume decreased by 40–60%, and specific energy consumption was approximately 0.30 kWh/m³. More intensive treatment increased the separation efficiency to 94–95% but resulted in a less favorable balance among energy consumption, reagent dosage, and resource recovery. Compared with mechanical mixing, the selected treatment system reduced flocculant consumption by 37.5%, treatment time by more than threefold, and specific energy consumption by 40%. These results support the use of modular on-site systems for process-water recirculation and reduced sludge-transport requirements at remote drilling sites.

Low-permeability reservoirs are constrained by low matrix transmissibility, heterogeneous pore/fracture connectivity, near-wellbore damage, and limited well-to-reservoir contact area. Multilateral and radial drilling can enlarge reservoir contact, but the resulting benefit depends on transmitted momentum, channel geometry and conductivity, cuttings removal, and path stability. This review separates three layers explicitly: systematic review findings, an author-proposed cross-scale coupling framework, and a design/verification methodology. The conceptual framework links generator and transmitted-pulse variables to connected rock damage, stress-dependent channel conductivity, skin factor, and productivity through four proposed validation interfaces with measurable inputs and outputs; these interfaces define future tests and are not claimed to have been validated as an integrated chain. The framework is not a monolithic solved multiphysics model. A multi-criteria methodology is proposed for selecting operating modes under lithological, stress, energy, cuttings-transport, wear, and productivity constraints. The review was conducted and reported in accordance with PRISMA 2020 and PRISMA-S. Of 2373 records identified, 243 full-text reports were assessed for eligibility, and 91 studies were included in the qualitative evidence synthesis. Owing to substantial methodological and physical heterogeneity, no pooled meta-analysis was justified. Accordingly, the integrated percussion–hydraulic system is explicitly classified as a conceptual TRL 1–2 synthesis; component-level field evidence must not be interpreted as validation of the complete integrated system.

High water cut in mature oil reservoirs reduces sweep efficiency and increases the operating burden associated with lifting, separation, produced-water treatment, transport, and reinjection. This systematic critical review integrates selective conformance control from diagnosis of water-production mechanisms through treatment selection and placement to field response and energy–water performance. PRISMA 2020/PRISMA-S screening of Scopus, Web of Science Core Collection, and OnePetro identified 346 records, of which 120 studies were included in the qualitative evidence synthesis. Final searches were completed on 5–10 August 2026. We propose the D–M–T–P–R–E evidence-integration framework—Diagnosis, Mechanism, Treatment, Placement/selectivity, Reservoir/production Response, and Energy–water efficiency—supported by evidence levels E1–E5, design-specific methodological appraisal, a legacy reporting-completeness descriptor, and cross-scale external-consistency assessment. The synthesis indicates that robust field performance requires mechanism-specific diagnosis, verified placement, measurable flow redistribution, sustained water reduction, and attributable incremental oil. The proposed framework provides a structured basis for decision support while preventing unsupported transfer of isolated laboratory metrics to field performance. The supplied extraction matrix retains 74 of the 120 studies as a post-inclusion traceability/comparability subset; endpoint-specific numerical comparisons were performed only where physical definitions, operating conditions, and source-level data were sufficiently comparable and verifiable, and no universal pooled meta-analysis was performed.

Sand production constrains artificial-lift reliability, shutdown management, and energy efficiency. This study develops an integrated experimental framework linking particle settling, bulk sand transport, shutdown-related plugging, and electrical demand using 12 anonymized Kumkol wells. The database contains 4380 daily records, 720 laboratory tests, 84 shutdown/restart events, 3600 energy points, 4800 high-frequency restart samples, and 132 maintenance events. In 480 settling column tests, Stokes yielded R² = 0.937 and MAPE = 24.8%; one-parameter calibration improved R² to 0.981 and MAPE to 11.3%, with leave-one-well-out MAPE of 11.4%. In 240 flow loop tests, the full-data non-unstable threshold was 1.052 m/s; nested held-out well accuracy was 87.9%, and the strict stable criterion yielded 83.8%. Shutdown duration was the dominant field predictor: plug odds rose 3.87-fold per 10 h, and nested threshold validation yielded 78.6% accuracy. For ESPs, the ratio-based SEC minimum occurred near 0.773 m/s. A denominator-free active power model controlling for pressure rise, VFD frequency, sand concentration, and well effects achieved R² = 0.851 and retained a positive velocity coefficient in all leave-one-well-out fits. The results define a locally calibrated energy–transport operating window; laboratory transport thresholds are not claimed as direct field setpoints without hydrodynamic scaling and on-well verification. The flow loop threshold block comprises only four independent wells; accordingly, its held-out results are treated as small-cluster evidence, and the numerical velocities remain laboratory reference constraints rather than direct field settings.