Water Pipeline Research Articles

Integrity Management of Subsea Pipelines for Water and Gas Transportation in Offshore Gas Storage Facilities

Abstract In the pilot test stage of N gas storage, relying on the construction of D oilfield, the injection production operation was achieved. The D355 subsea water transmission pipeline from the old A artificial island to the B artificial island was converted into a gas transmission pipeline. To ensure the safe and stable operation of the pipeline during the test stage, the feasibility was determined through verification and analysis of the pipeline; High consequence area identification and risk assessment have been carried out on the pipeline, and the risk level is within an acceptable range; Due to the lack of internal testing conditions, a comprehensive inspection and evaluation of the pipeline was conducted, including underwater magnetic memory non-destructive testing, external testing, and pressure testing; In response to the detected problem of exposed pipelines, concrete pads were used for interlocking treatment; In response to the scaling on the inner wall of the pipeline, conservative cleaning measures have been taken, including neutral immersion cleaning and non clogging cleaning with steel wire balls. After thorough argumentation, testing, and treatment, the pipeline has operated well after being put into operation, which is a successful practice for the integrity management of old submarine pipelines. It provides valuable integrity management experience for the gathering and transformation of various offshore oil and gas fields and the construction of offshore gas storage facilities.

Research and Application of Leakage Monitoring Techniques for Gas Field Water Pipelines

Abstract To study the effectiveness and application effects of leakage monitoring techniques for gas field water pipelines in the Sichuan-Chongqing region, seven kinds of flow limitation holes with different diameters were used to simulate the leakage of the gas field water pipeline to carry out a field test. The monitoring conditions of two leakage monitoring techniques, namely dynamic pressure wave compound method and negative pressure wave and transmission balance method, were compared and analyzed under different working conditions. The test results showed that: (1) When the pipeline was full, the leakage with apertures being smaller than 2 mm could not be effectively monitored. A single-end alarm could be achieved using the dynamic pressure wave compound method, but the positioning was ineffective. An alarm could not be effectively achieved using the transmission balance method. (2) When the pipeline was full, for the leakage with apertures being 2 mm and above, early warning could be well achieved using the both methods, and the monitoring effects were nearly the same, with the average positioning error being about 48 m and the average alarm response time being about 58 s. (3) When there were empty pipe slug flows in the pipeline, only apertures being 5 mm and above could be alarmed; however, positioning could not be effectively achieved, and system technical indicators could not be reached. (4) When there were large elevation differences in the gas field water pipeline and empty pipe slug flows could not be eliminated, the both techniques were not applicable.

Enhancement of heat dissipation efficiency in the CSNS target through the innovative design of a serial cooling water channel

This paper presents a coupling of the Monte Carlo method with computational fluid dynamics (CFD) to analyze the flow channel design of an irradiated target through numerical simulations. A novel series flow channel configuration is proposed, which effectively facilitates the removal of heat generated by high-power irradiation from the target without necessitating an increase in the cooling water flow rate. The research assesses the performance of both parallel and serial cooling channels within the target, revealing that, when subjected to equivalent cooling water flow rates, the maximum temperature observed in the target employing the serial channel configuration is lower. This reduction in temperature is ascribed to the accelerated flow of cooling water within the serial channel, which subsequently elevates both the Reynolds number and the Nusselt number, leading to enhanced heat transfer efficiency. Furthermore, the maximum temperature is observed to occur further downstream, thereby circumventing areas of peak heat generation. This phenomenon arises because the cooling water traverses the target plates with the highest internal heat generation at a lower temperature when the flow channels are arranged in series, optimizing the cooling effect on these targets. However, it is crucial to note that the pressure loss associated with the serial structure is two orders of magnitude greater than that of the parallel structure, necessitating increased pump power and imposing stricter requirements on the target container and cooling water pipeline. These findings can serve as a reference for the design of the cooling channels in the target station system, particularly in light of the anticipated increase in beam power during the second phase of the China Spallation Neutron Source (CSNS Ⅱ).

Sewerage and drainage manhole measuring using terrestrial laser scanning techniques

ABSTRACT A common method for measuring sewer and drainage manholes with tape measure lacks precision in cases of sediment accumulation or deep manholes, impacting data accuracy. This paper proposed a method for measuring sewer and drainage manholes using terrestrial laser scanning. This method first utilizes a plane fitting equation and the RANSAC method to determine the ground and segmentation planes, enabling automatic trimming of the point cloud of the manhole. Subsequently, the pipe’s inlet and outlet extraction is done using the point cloud combining Region Growing method. Finally, according to the feature of cylinder pipe and elliptical cylinder pipe, the inlet and outlet are reconstructed using the extracted point cloud. Experimental results show that the radius of pipe’s inlet or outlet can be measured by the proposed method with an accuracy of 5.20 mm, the height difference of the manhole can be measured with an accuracy of 7.05 mm, meeting the requirement of a permissible deviation of 10 mm for measuring the lowest point of manhole specified in the “ Code for construction and acceptance of water and sewerage pipeline works “ (GB50268-2008).

Isolation and characterization of a novel bacterium that promotes the degradation of poly(glycolic acid) by its extracellular esterase under thermophilic conditions

Poly(glycolic acid) (PGA) is widely utilized in the shale oil and gas industry owing to its biodegradable nature, as well as superior mechanical and barrier properties. However, PGA degradability is limited by environmental conditions such as temperature and pH, and using acids to optimize the degradation can have adverse environmental impact. Thus, it is essential to identify methods that can effectively promote the degradation of PGA under mild conditions, such as microbial degradation. In the present study, strain DB14, a bacterium that promotes PGA degradation, was isolated from drain water of a steam pipeline. Sequence analysis of the 16S rRNA gene of the bacterium revealed that it is mostly closely related to Geobacillus icigianus; however, it also differed from Geobacillus icigianus in several physiological properties. To investigate PGA degradation by strain DB14, a PGA film and disc were incubated with the strain. The residual weight of the PGA film (thickness: 170 μm) significantly reduced after incubation, whereas the decrease in the thickness of the PGA disc (thickness: 3 mm) was relatively small. The penetration of water, the bacterium, and the extracellular enzymes into the interior from the reaction-erosion front of the PGA disc may be inhibited by the high barrier performance of PGA. Strain DB14 was also found to change the pH of the surrounding environment to approximately 8–9. To investigate the effect of pH on PGA degradability, degradation tests with crude extracellular enzymes derived from strain DB14 were conducted in various buffers. The results showed that the degradation activity was highest at pH 8, which implied that DB14 efficiently maximized the hydrolytic capacity of its enzyme for degrading PGA. Thus, this study provides a basis for developing environmentally friendly technologies that can promote the degradation of PGA molding articles, especially those used in wellbores for oil and gas recovery.

Earthquake damage mitigation methods for buried pipelines under compressive loads: A case study of the Thames water pipeline

Promoting tensile failure by providing a proper orientation angle between the pipe axis and the fault line is the main seismic design philosophy for buried steel pipelines. However, most of the severe damage and failures experienced by pipelines are mainly due to negative crossing angle and thus compressive loads acting along the pipeline. This paper investigates different earthquake damage mitigation methods such as Carbon Fiber Reinforced Polymer (CFRP) wrapped pipes, Steel Pipes for Fault Crossing (SPF), and corrugated pipes for buried steel pipelines which are mainly subjected to compressive loads. Therefore, the Thames water transmission pipeline, which is a well-known case study, that suffered major and minor damage due to compressive forces in the 1999 Kocaeli earthquake, is considered to simulate and compare the earthquake damage mitigation capabilities of these countermeasures. The numerical studies are performed by using a three-dimensional nonlinear finite element model. The results show that the use of CFRP composites in buried pipelines, regardless of their thickness, wrapping length, or layer orientation, does not have the expected damage reduction effect, but does increase the effective length between major wrinkles or change the type of pipe failure. On the other hand, SPFs and corrugated pipes are more effective in earthquake damage reduction due to their high axial and rotational capabilities.

Effects of Expelled Air during Filling Operations with Blocking Columns in Water Pipelines of Undulating Profiles

Effects of Expelled Air during Filling Operations with Blocking Columns in Water Pipelines of Undulating Profiles

Space–time prediction of residual chlorine in a water distribution network using artificial intelligence and the EPANET hydraulic model

ABSTRACT Insufficient knowledge of physical models and difficulty in fitting statistical models impair the choice of models to regulate residual chlorine in water distribution. This paper compared the performance of physical and statistical models in predicting residual chlorine concentrations in drinking water distribution. Drinking water was sampled from the downstream 128 water points water pipeline. Online chlorine concentrations were determined at water draw-off points. EPANET, the physical model, was used because of its efficiency in tracking dissolved chemicals. Statistical models used were regression, decision tree, random forest and artificial neural network. In the whole distribution network, the artificial neural network performed at R2 of 94%, multi-linear regression (62%), random forest (55%), decision tree (41%), and EPANET (24%). However, EPANET yielded improved performance with R2 above 70% when separately applied to individual sub-distribution networks; hence, is recommended for secondary chlorination in small distribution networks. For modelling large distribution networks, statistical models, especially an artificial neural network, are recommended. However, such cases still need support from confirmatory systems of interpretable parametric or hydraulic models that can achieve good performance with R2 ≥ 80%. Water utilities can use these results to deploy model(s) for managing residual chlorine within safe limits of residual chlorine concentration in water distribution practice.

Evaluating Life-Cycle Unit Costs of Traditional Cement Concrete and New Polymer Concrete Manholes in Wastewater Systems

Wastewater manholes are crucial infrastructure components in sewage systems. They provide necessary access points for inspection and maintenance. However, limited studies were conducted on the life-cycle cost analysis of manholes. The primary objective of this study is to compute and compare the Life-Cycle Unit Cost (LCUC) of cement concrete and polymer concrete manholes to identify a cost-effective alternative for public agencies. To achieve the objective, this study analyzed commonly used 1.83 m diameter manhole data; 343 cement concrete manhole and 88 polymer concrete manhole cost data were collected from the Clark County Water Reclamation District (CCWRD), Las Vegas, Nevada, United States. The results show that the initial costs of polymer concrete are higher than those of traditional cement concrete. Statistical tests were conducted to determine the group differences. The findings show that the LCUCs of polymer concrete manholes are significantly cost-effective when compared to traditional cement concrete manholes. Public agencies can utilize polymer concrete manholes to save costs in future water and wastewater pipeline manhole construction projects.

Experimental study on hydrate blockage formation and decomposition in gas-dominated Fluctuating pipes

Current research pertaining to hydrate flow assurance in the transportation of deep-sea natural gas through undulating pipelines remains sparse. Employing a novel undulating pipeline equipped with multipoint-distributed sensors, we delve to the processes of hydrate generation, migration, deposition, blockage, and decomposition. Our findings reveal that the upward inclination sections of both lifting and underlying pipes are particularly vulnerable to hydrate blockage. The lifting pipe is not conducive to hydrate deposition and blockage, whereas the underlying pipe poses a heightened risk for hydrate formation. Increasing subcooling leads to a reduction in blockage duration and sloughing frequency, alongside an extension in decomposition time. Furthermore, increasing the water injection rate and pipeline curvature prolongs the blockage of the lifting pipe. However, the impact of the water injection rate on the underlying pipe is negligible. Increasing pipeline curvature promotes the blockage of the underlying pipe. We propose models that encapsulate hydrate blockage and decomposition based on varying gas–liquid distributions. This research fills the gap in the study of hydrate blockage and decomposition in undulating pipelines and provides a reference for monitoring hydrate risks in natural-gas transmission pipelines.

Distributed Low-Power Electronic Units for Sensing and Communication in Water Pipeline Monitoring

Distributed Low-Power Electronic Units for Sensing and Communication in Water Pipeline Monitoring

Characteristics and Leak Localization of Transient Flow in Gas-Containing Water Pipelines

Characteristics and Leak Localization of Transient Flow in Gas-Containing Water Pipelines

Investigating the internal erosion behavior and microscopic mechanisms of chemically stabilized soil: an experimental study

IntroductionInternal erosion triggered by water pipeline leaks seriously threatens the stability of the urban ground. Hangzhou, a city in Zhejiang Province, China, is facing critical challenges due to urban ground collapse (UGC) caused by internal erosion. However, there is a lack of research on the prevention of UGC by improving the internal erodibility of underground soil. Addressing this issue is of utmost importance to ensure the city’s stability and safety. This paper proposes to improve the internal erodibility of typical sandy silt soils with chemical stabilisers.MethodsThe effects of three chemical stabilisers, lignosulphonate (LS), lime (LI), and lignin fibre (LF), on the critical shear stress (τc) and erosion coefficient (kd) of sandy silt soils were investigated, which from Hangzhou, Zhejiang, China, by the hole erosion test (HET) at different mixing amounts and at different conservation times.ResultsThe findings indicate that LF mainly improves the erosion resistance of sandy silt by increasing τc, and the maximum increase is 2.38 times; LI mainly improves the erosion resistance by decreasing kd, and the maximum decrease is 2.18 times. After adding LS, τc and kd did not change significantly. The scanning electron microscope (SEM) test revealed that the inclusion of LF led to the formation of larger agglomerates in the sandy silt soil. The microstructure of sandy silt soil remained dispersed even after adding LS. Various chemical stabilisers used to improve sandy silt soils exhibited distinct erosion mechanisms. Sandy silt soils improved with LF exfoliated into agglomerates, displaying high resistance to erosion. On the other hand, the sandy silt treated with LF still lacks a protective layer and shows minimal improvements in its ability to withstand erosion. In contrast, the LS-amended sandy silt remains stripped with individual soil particles with insignificant changes in erosion resistance.DiscussionThis study can provide a conceptual framework for choosing foundation treatment techniques in future urban development projects.

Characteristics of Transient Flow in Rapidly Filled Closed Pipeline

In this study, a one-dimensional mathematical model based on rigid theory is developed to evaluate the maximum water filling flow rate and filling time of closed pipeline water supply systems during rapid-filling processes. Polynomial fitting is utilized for prediction, and numerical simulation results are analyzed to understand the variations in maximum water filling flow rate, filling time, and pressure with respect to opening valve time, air valve area, filling head, and segmented filling pipe length. The findings highlight the significant impact of the filling head on the maximum water filling flow rate, while the filling time is predominantly influenced by the gas discharge coefficient. Rapid changes occur only at the initial stage of rapid filling, reaching the maximum value with a very high acceleration (around t = 4 s). It is observed that pressure fluctuations in the gas–liquid two-phase flow inside the pipeline lead to velocity differences and periodic changes in gas pressure opposite to the filling head. When the gas discharge coefficient reaches approximately 0.3, pressure variation within the water supply system diminishes, and the time and flow rate required for pipeline filling become independent of the discharge coefficient. This study suggests the use of a segmented filling approach to ensure the effectiveness and stability of pipeline filling.

Proposed Approach for Modelling the Thermodynamic Behaviour of Entrapped Air Pockets in Water Pipeline Start-Up

Proposed Approach for Modelling the Thermodynamic Behaviour of Entrapped Air Pockets in Water Pipeline Start-Up

Adaptive Signal Extraction Based on RLMD-SVD for Water Pipeline Leakage Localization

Adaptive Signal Extraction Based on RLMD-SVD for Water Pipeline Leakage Localization

An interpretable machine learning-based pitting corrosion depth prediction model for steel drinking water pipelines

Steel pipes are a crucial element of the water supply system and are necessary for safely delivering large quantities of water from purification plants to consumers. Corrosion is a significant factor that deteriorates the interior and exterior of the steel pipes. Although the effectiveness of machine learning has been demonstrated in various fields, machine learning has rarely been used to identify corrosion mechanisms in buried steel pipes. A hybrid machine-learning–based corrosion depth prediction model was developed by integrating a corrosion depth trend prediction model based only on elapsed years with machine-learning algorithms. Shapley additive explanation (SHAP) was used to analyze the hybrid machine-learning–based corrosion depth prediction models, revealing corrosion mechanisms and explaining the interactions among influencing factors through global and local interpretations. The SHAP local interpretation showed that the hybrid machine-learning–based corrosion depth prediction models can effectively capture the interrelationship between soil and water corrosiveness.

Impact of Seismic Geohazards on water supply systems and pipeline performance: Insights from the 2023 Kahramanmaras Earthquakes

This study delves into the profound repercussions of geohazards on water supply systems, specifically in the aftermath of the Kahramanmaras earthquakes. The influence of these geohazards was far-reaching, impacting a vast geographical expanse affected by the seismic events. The primary focus of this investigation centers on the provinces of Adiyaman, Gaziantep, and Hatay, providing representative damage examples from the earthquake-affected areas. The study illustrates various types of pipe failures induced by geohazards such as fault displacements, landslides, and liquefaction. The analysis encompasses diverse cases of damage, starting from the water resources, progressing through issues at transmission lines, and extending to challenges faced by pumping and treatment facilities. Key aspects of damages and geohazards are presented, shedding light on the intricate dynamics of these interactions. It is crucial to note the scarcity of real cases in the existing literature, emphasizing the need for extensive site investigations and dedicated research endeavors to construct a comprehensive database of case histories in this domain. This study addresses this gap, contributing valuable insights into the tangible impacts of geohazards on water supply systems. By comprehending and effectively addressing the risks associated with geohazards, water supply organizations can fortify the safety and resilience of their infrastructure. The findings presented herein offer a foundation for informed decision-making and strategic planning, fostering a proactive approach to mitigate potential damages and enhance the overall robustness of water supply systems in regions prone to seismic events and associated geohazards.

Strain response law of large-diameter PCCPs under internal water pressure based on BOTDA

Prestressed concrete cylinder pipes (PCCPs) are widely used in trans-regional large-scale water conveyance projects, so it is of great significance to monitor their condition. In this paper, the Brillouin Optical time domain analysis (BOTDA) sensing system is used to measure the circumferential strain of PCCPs under internal water pressure. The test results show that BOTDA technology can accurately monitor the shape variable of the outer wall of the pipe. Moreover, the circumferential strain is not uniform, and there are multiple relative maxima and minima. When the internal water pressure is 1.2 MPa, the absolute maximum and minimum strain is 579.17με and 217.78με respectively. In addition, there is a positive linear correlation between the strain and the internal water pressure, but the hysteresis effect is obvious in the case of insufficient water filling. This study provides reliable experimental data for the application of distributed optical fiber sensing technology in large-diameter water pipelines.

Research on pressure propagation in long-distance water pipelines for fault conditions by VMD and wavelet transform

Long-distance water pipelines in complex geographical environments face potential risks such as leaks. This study uses variational mode decomposition (VMD) and continuous wavelet transform (WT) to analyze pressure fluctuation signals in pipelines for detecting and locating leaks and other anomalies. CFD simulations are conducted to obtain pressure fluctuation data under various fault conditions. The pressure signals are then decomposed into multiple Intrinsic Mode Functions (IMFs) using VMD, and WT is applied to analyze their time–frequency characteristics. The results show significant differences in amplitude and frequency of IMF components between fault and normal conditions, with reduced amplitude and altered frequency under fault conditions, providing a basis for fault detection. Additionally, the IMF characteristics differ at different fault locations, aiding in fault localization. This research offers an effective method for leak detection and localization in long-distance pipelines, crucial for enhancing safety and stability.