Gathering Pipeline Research Articles

Brief Discussion on Construction Technology and Quality Analysis of Oil Field Surface Construction Gathering and Transmission Pipeline

Brief Discussion on Construction Technology and Quality Analysis of Oil Field Surface Construction Gathering and Transmission Pipeline

Failure Analysis on Corrosion Perforation of L245N Gathering Pipeline

Failure Analysis on Corrosion Perforation of L245N Gathering Pipeline

Experimental study on corrosion of 20# steel in oil-water stratified liquids based on wire beam electrode technique

PurposeOil-water two-phase flow is the most prevalent medium in oil field gathering pipelines, and the corrosion of pipelines is often highly localized. Therefore, the purpose of this paper is to investigate the corrosion behavior of 20# pipeline steel in the oil-water stratified liquids, vary the water content of the upper emulsion and study the difference of the corrosion process.Design/methodology/approachCombine the wire beam electrodes (WBE) technique and the corrosion weight loss method to investigate the corrosion behavior of 20# steel in produced water simulation fluid and oil-water stratified liquids, and a corrosion mechanism model was established for analysis and explanation.FindingsThe results of mass loss experiments showed that the average corrosion rate increased with the increase in the water content of the upper emulsion. The corrosion current distribution maps indicated that the most serious corrosion occurred in the produced water simulation liquid, and the corrosion process showed the law of waterline corrosion. In addition, it was also found that the corrosion of the WBE in the stratified liquids had obvious non-uniformities. The electrode wires at the oil-water interface suffered from severe corrosion, caused by the dissolution of crude oil acids in water and the uneven distribution of oxygen in the corrosive medium.Originality/valueThe WBE technique provides a deep insight into the corrosion phenomena at the oil-water interface, which is helpful for characterization of the non-uniformity of corrosion parameters and evaluating the risks of multiphase corrosive media.

Effect of flow field on particle erosion in eroded square elbows

Erosion often occurs on the inner wall of gathering pipelines. Even if the particle size is small, the cumulative erosion may also cause serious erosion on pipelines and even leads to leakages. In order to learn erosion on elbows of pipelines in natural gas stations, mechanisms analysis and computational fluid dynamics (CFD) method were used to investigate erosion on square elbows based on a case of elbows erosion in a gas gathering station. The results show that there are erosion sensitive areas on the eroded surface of elbows which are more likely to be eroded, erosion prediction of elbows could be obtained through CFD method. It is concluded that researches on erosion are important in oil and gas gathering industry and could be a good guiding for life prediction, inspection and operational safety protection of gathering pipelines.

General models for topology layout of oil and gas star-tree pipeline network

Oil&gas gathering pipeline network structure is a significant part of oil&gas field construction, and the rational construction of pipeline network is directly related to the efficiency and benefits of oil&gas field production. Therefore, optimizing the gathering and transportation system of oil and gas fields is the key to reducing development costs. The star-tree type pipe network is widely used in the gathering and transportation system. In order to optimize the star-tree pipe networks (STPNs) that has restrictions on the processing capacity and gathering radius of the station as a whole, this paper establishes four models of pipe network layout with specific constraints. They are Mixed-Integer Linear Programming Models with a large number of discrete variables. We take two virtual fields as examples, use CPLEX solver to solve the above four models as a whole, to obtain the optimal scheme, and also figure out the investment of the pipeline network. We further optimize the hierarchical optimization of the pipeline network with special constraints, then compare and analyze results obtained by the overall optimization. Finally, models are applied to an actual oil field and an actual gas field as examples to optimize the layout, which verifies the validity and feasibility of the models.

Analysis on corrosion-induced failure of shale gas gathering pipelines in the southern Sichuan Basin of China

In the shale gas field in southern Sichuan Basin, the corrosion-induced failure has been observed. In this paper, first, the corrosion phenomenon was analyzed. Second, the causes of corrosion were analyzed thoroughly from the aspects of corrosive environment, materials, and corrosion products. Finally, the field water environment was simulated, and the result showed the following: SRB is one of the main causes of corrosion and perforation of shale gas pipelines, bacterial enrichment is the primary reason for local corrosion, and CO2 promotes the formation of bacterial film and accelerates corrosion.

Corrosion mechanism and anticorrosion technology of oil and gas gathering and transportation pipeline

In the process of oilfield exploitation, the composition of crude oil is relatively complex, which may have strong corrosive medium, and the oil field gathering and transportation pipeline is distributed in various areas of the oilfield, which plays an important role. The corrosive medium of crude oil has a certain corrosive effect on the oil field gathering and transportation pipeline, and once the corrosion is serious, it will cause the leakage of the gathering and transportation pipeline. China’s oilfields have experienced many years of continuous development, some oilfields have entered the middle and late stage of exploitation, and have made certain achievements in various stages of exploitation. We have conducted in-depth research and Analysis on the corrosion factors of oil gathering and transportation pipeline, which consumes a lot of manpower, material resources and financial resources. Therefore, we need to analyze and study the factors influencing the corrosion of oil gathering and transportation pipeline, formulate effective anti-corrosion measures according to the actual situation, extend the service life of oil gathering and transportation pipeline, and promote the longterm development of oil field exploitation and operation.

Pitting Judgment Model Based on Machine Learning and Feature Optimization Methods

Pitting corrosion seriously harms the service life of oil field gathering and transportation pipelines, which is an important subject of corrosion prevention. In this study, we collected the corrosion data of pipeline steel immersion experiment and established a pitting judgment model based on machine learning algorithm. Feature reduction methods, including feature importance calculation and pearson correlation analysis, were first adopted to find the important factors affecting pitting. Then, the best input feature set for pitting judgment was constructed by combining feature combination and feature creation. Through receiver operating characteristic (ROC) curve and area under curve (AUC) calculation, random forest algorithm was selected as the modeling algorithm. As a result, the pitting judgment model based on machine learning and high dimensional feature parameters (i.e., material factors, solution factors, environment factors) showed good prediction accuracy. This study provided an effective means for processing high-dimensional and complex corrosion data, and proved the feasibility of machine learning in solving material corrosion problems.

Analysis of the corrosion failure causes of shale gas surface pipelines

AbstractA shale gas gathering and transportation pipeline in a good block in Sichuan Province started leaking after less than a year of operation. To investigate the causes of corrosion of the sulfate‐reducing bacteria (SRB), optical microscopy, scanning electron microscopy, and X‐ray diffraction were used to analyze the corrosion and perforation of the shale gas surface pipeline in conjunction with bacterial corrosion simulation experiments. The results showed that the pipeline material (L360N) conformed to the requirements of the American Petroleum Institute 5 L standard and that extracellular polymeric substances were present in the corrosion pits. The corrosion products mainly included FeCO3, FeS, CaCO3, MgCO3, and Fe mineralization. At 40°C, the uniform corrosion rate of L360N in the simulation experiment was 0.234 mm/a, and the local corrosion rate was 0.458 mm/a. SRB, saprophytes, and iron bacteria were detected in the on‐site water medium and corrosion products, indicating that the main causes of shale gas pipeline corrosion are bacterial and CO2 corrosion.

Investigation of gas gathering pipelines operation efficiency and selection of improvement methods

Purpose: The article implies theoretical and experimental studies of the liquid pollution accumulations impact on the efficiency of gathering gas pipelines operation at the Yuliivskyi oil and gas condensate production facility (OGCPF). Research of efficiency of gas pipelines cleaning by various methods. Design/methodology/approach: The research methodology consists of determining the hydraulic efficiency of gathering gas pipelines before and after cleaning of their internal cavity by different methods and comparing the obtained results, which allows to objectively evaluate the efficiency of any cleaning method. CFD simulation of gas-dynamic processes in low sections of gas pipelines with liquid contaminants. Findings: Experimental studies of cleaning efficiency in the inner cavity of the gas gathering pipelines of the Yuliivskyi OGCPF by various methods, including: supply of surfactant solution, creating a high-speed gas flow, use of foam pistons were performed. It was established that cleaning the inner cavity of gas gathering pipelines by supplying a surfactant solution leads to an increase in the coefficient of hydraulic efficiency by 2%-4.5%, creating a high-speed gas flow by 4%-7%, and under certain conditions by 8%-10 % and more. However, for two gas pipelines the use of foam pistons allowed to increase the coefficient of hydraulic efficiency from 5.7 % to 10.5 % with a multiplicity of foam from 50 to 90. be recommended for other deposits.The results of CFD simulation showed that the accumulation of liquid contaminants in the lowered sections of gas pipelines affects gas-dynamic processes and leads to pressure losses above the values provided by the technological regime. With the increase in liquid contaminants volume the pressure losses occur. Moreover, with a small amount of contamination (up to 0.006 m3), liquid contaminants do not have a significant effect on pressure loss. If the contaminants volume in the lowered section of the pipeline is greater than the specified value, the pressure loss increases by parabolic dependence. The increase in mass flow leads to an increase in the value of pressure loss at the site of liquid contamination. Moreover, the greater the mass flow, the greater the impact of its changes on the pressure loss. The CFD simulation performed made it possible not only to determine the patterns of pressure loss in places of liquid contaminants accumulation in the inner cavity of gas pipelines, but also to understand the gas-dynamic processes in such places, which is an unconditional advantage of this method over experimental. Research limitations/implications: The obtained simulation results showed that the increase in the volume of liquid contaminants in the inner cavity of gas gathering pipelines leads to an increase in pressure losses above the value provided by the technological regime. To achieve maximum cleaning of gas gathering pipelines, it is necessary to develop a new method that will combine the considered. Practical implications: The performed experimental results make it possible to take a more thorough approach to cleaning the inner cavity of gas gathering pipelines and to forecast in advance to what extent the hydraulic efficiency of gas gathering pipelines can be increased. Originality/value: The obtained results of CFD simulation of gas-dynamic processes in lowered sections of gas pipelines with liquid contaminants, experimental studies of the effectiveness of various methods of cleaning the inner cavity of gas gathering pipelines has original value.

Blocking characteristics of high water-cut crude oil in low-temperature gathering and transportation pipeline

High-pour point and high-viscosity crude oil can be gathered and transported below the pour point during a high water-cut period. However, oil under these conditions can easily aggregate, thereby blocking the pipeline. In this study, a comprehensive field experimental pipeline system (368 m long and 64 mm internal diameter (ID)) was developed to investigate the pipeline blockage mechanism. The changes in the pressure, temperature, and oil–water morphology during cooling experiments were studied. The pipe flow regime under different flow rates of water-blending conditions was divided into blockage, transition, and safe operation modes. The blocking mode was divided into stable development, rising volatility, and fast congestion periods. The rheological change of non-Newtonian crude oil during the cooling process was the dominant mechanism of blockage that caused successive decreases in the oil–water interface until the water phase channel was blocked, finally causing a surge in the flow resistance and pressure drop. The correlation equation of the single well temperature limits as functions of fluid flow rate and water-cut was established, and the error between the prediction results and experiments was between 0.12–0.20 °C. The prediction method for the minimum water-blending flow rate was combined with heat transfer analysis, and the corresponding temperature limit was less than the pour point of crude oil at approximately 1–10 °C (liquid flow rate: 5–30 m3/d, water-cut: 80%–90%). The investigations conducted in this study further ascertained the crucial impact of non-isothermal and non-Newtonian characteristics on the low-temperature oil–water two-phase flow.

Study on corrosion mechanism and the risk of the shale gas gathering pipelines

Corrosion and perforation accidents often occur in shale gas gathering and transportation pipelines, which causes serious economic losses. The medium in shale gas gathering pipelines is complex, and the corrosion rate is fast under the combined action of many factors. In this paper, the corrosion mechanism of shale gas gathering and transportation pipelines was studied by field data analysis and experiments. By means of multiphase flow simulation analysis and magnetic flux leakage internal detection, the characteristics and distribution of pipeline corrosion defects were identified, and the corrosion sensitive area was further determined. The results show that in the shale gas gathering pipelines, there were multiple corrosive media of CO2, O2 and SRB. The local corrosion was more serious under the promotion of Cl- and low liquid flow rate. The 3–9o'clock position on the low-lying and uphill section of the pipelines were the corrosion sensitive areas. Through the analysis of internal corrosion mechanism and ERF curves, there were many high-risk corrosion areas in the pipelines.

Study on the Segmental Pigging Process for the Wet Gas Gathering and Transportation Pipelines of the Puguang Gas Field

Abstract The gathering and transportation pipeline known as Line 1 of Puguang Gas Field has the characteristics of wet gathering and transportation containing high sulfur content, large drops, and liquid loading in low-lying areas. In the process of one pigging operation on the site, the surge volume provided by the no. 1 separator in the master gas gathering station was not effectively utilized and the time intervals for the neighboring pipeline sections were too long. In this paper, we designed several pigging proposals. OLGA was applied to analyze the operating parameter changes for the gathering and transportation pipeline Line 1, which finally determined a reasonable pigging sequence. We designed and selected the “optimal pigging proposal”, which the time duration for the pigging operation of the seven pipeline sections was decreased to 16.91 h. Guided by the “optimal pigging proposal”, the downstream pipeline sections will be challenged by the risks of ice blockage. The ground eddy device was improved in the article, for the purpose of draining liquid loadings in low-lying areas in the Puguang Gas Field and controlling the slug flow. In addition, the application effects of the device were analyzed.

Failure Analysis for Girth Weld of Gathering Pipelines

Through failure generalization, fracture feature analysis and material performance test, a comprehensively analysis was made on the fracture failure analysis for girth weld of gathering pipelines containing H2S gas. The results showed that the fracture failure might be mainly due to sulfide stress cracking in the girth weld. The crack originated from the fusion line on the inner surface of girth weld and extended along the girth weld to outside closed to bends. The sulfide stress cracking of the girth weld was caused by the intersection of multiple factors. The service condition was located in SSC 3 zone and the SSC risk of girth weld was high. The girth weld itself was not been stress-relieved, and its ability to resist SSC was poor. Due to low wall thickness, welding defects, welding stress and additional load, the actual stress of weld was higher.

Natural Gas Gathering and Transmission Pipelines and Social Vulnerability in the United States.

Midstream oil and gas infrastructure comprises vast networks of gathering and transmission pipelines that connect upstream extraction to downstream consumption. In the United States (US), public policies and corporate decisions have prompted a wave of proposals for new gathering and transmission pipelines in recent years, raising the question: Who bears the burdens associated with the existing pipeline infrastructure in the US? With this in mind, we examined the density of natural gas gathering and transmission pipelines in the US, together with county‐level data on social vulnerability. For the 2,261 US counties containing natural gas pipelines, we found a positive correlation between county‐level pipeline density and an index of social vulnerability. In general, counties with more socially vulnerable populations have significantly higher pipeline densities than counties with less socially vulnerable populations. In particular, counties in the top quartile of social vulnerability tend to have pipeline densities that are much higher than pipeline densities for counties in the bottom quartile of social vulnerability. The difference grows larger for counties at the upper extremes of pipeline density within each group. We discuss some of the implications for the indigenous communities and others affected by recent expansions of oil and gas infrastructure. We offer recommendations aimed at improving ways in which decision‐makers identify and address the societal impacts and environmental justice implications of midstream pipeline infrastructure.

Effect of SDS surfactant on gas-liquid flow and slug characteristics in slightly upward pipeline

A new pigging approach with SDS (Sodium dodecyl sulfate) surfactant was proposed for foam drainage in the gathering pipelines with wet gas production, especially for the pipeline section with a great pigging risk. For this purpose, the loop of gas-liquid two-phase flow with a 3 ° slightly upward pipeline was designed. The flow pattern characteristics of gas-liquid two-phase flow were collected by a high-speed camera, and the flow patterns with typical morphological structure were classified. Ultrasonic Doppler velocimeter and ultrasonic transducer were used to measure the velocity signal of the liquid phase near the pipe, and the slug frequency was calculated accurately according to the change of velocity profile data. The slug length was measured by the signal collected by pressure and differential pressure transmitter. The results show that with the addition of SDS surfactant, the flow pattern of gas-liquid two-phase flow is obviously improved, and the working condition of slug flow is suppressed. Besides, in the specific slug flow condition, the slug frequency decreases significantly and the slug length increases. It indicates that the addition of SDS surfactant is favorable to liquid discharge, and provide a reference value for the application of SDS surfactant in foam drainage in wet-gas gathering pipelines.

Modification of D-W model for corrosion rate of shale gas pipeline under the synergistic corrosion of SRB and CO2

Purpose The purpose of this paper is to develop an equation for the synergistic corrosion of SRB and CO2 based on the D-W model. Design/methodology/approach The bacterial types in the a and ß pipelines were studied by the most probable number method, and the corrosion morphology of L360 in pipeline water samples was studied by surface analysis. The corrosion rate of L360 was studied using the weight loss method. The gray correlation method was used to calculate the degree of correlation between the influencing factors of corrosion under the synergistic effect of CO2 and SRB. The curve obtained from PIPESIM software and experiments data was then fitted using multiple non-linear regression method by MATLAB software. Findings The equation was used to predict the corrosion of the ß pipeline for verification, and it was found that seven out of ten excavation sites were within a 20% error range. Originality/value Using the gray correlation method, an equation that considers synergistic corrosion of SRB and CO2 has been developed based on the D-W model. The equation could be used to predict the corrosion rate of shale gas gathering pipelines through SRB and CO2 synergistic corrosion.

General Models for Optimal Design of Star–Star Gathering Pipeline Network

AbstractThe arrangement of gas gathering stations (GGS) and central processing facilities (CPF) in the natural gas gathering pipeline network really counts. Their reasonable number and locations ca...

Experimental effectiveness studies of the technology for cleaning the inner cavity of gas gathering pipelines

Purpose: The purposes of the article are to determine the hydraulic efficiency of two gas gathering pipelines of the Yuliivskyi oil and gas condensate production facility (OGCPF) and develop a set of measures to increase it; to experimentally determine the efficiency of using foams to increase the hydraulic characteristics of the gas gathering pipelines in the Yuliivskyi OGCPF; to develop a set of measures that will help to improve the hydraulic characteristics of gas gathering pipelines. Design/methodology/approach: The research methodology consists in determining the hydraulic efficiency of gas gathering pipelines before and after cleaning their inner cavity with foams with different expansion ratios and comparing the obtained values, which allows to objectively assess the efficiency of this cleaning method. The studies were performed within the framework of research and development work by the specialists of the Ukrainian Scientific Research Institute of Natural Gases. Findings: The pilot testing was carried out to determine the efficiency of cleaning the inner cavity of gas gathering pipelines with foams with different expansion ratios. It showed positive results. It was determined that cleaning the inner cavity of gas gathering pipelines with foams with the expansion ratio from 80 to 90 led to an increase in the hydraulic efficiency coefficient by 10.5%, and with foams with the expansion ratio from 50 to 60 – by 5.7%. The measures taken to clean the inner cavity of gas gathering pipelines from liquid contaminations have proven their efficiency and can be recommended for other fields. Research limitations/implications: The obtained results show that it is reasonable to conduct the experimental studies on the efficiency of cleaning the inner cavity of gas gathering pipelines with the foams with higher expansion ratios. To achieve the maximum quality of cleaning the gas gathering pipelines, it is necessary to develop a new method that will combine the use of foam and gel piston.Practical implications: The performed experimental studies help to take a more reasonable approach to cleaning the inner cavity of gas gathering pipelines with foams and to predict in advance the effect of the foam expansion ratio on the hydraulic efficiency of gas gathering pipelines. Originality/value: The experimental studies on the effect of foam expansion ratios on the hydraulic efficiency of gas gathering pipelines are original.

Experimental and numerical simulation of erosion-corrosion of 90° steel elbow in shale gas pipeline

Coexistence of the solid particle erosion and acid liquid corrosion is common in shale gas gathering and transportation pipelines. It is conceivable that the synergistic effect of erosion and corrosion accelerates the pipeline damage process. In this research, a novel experimental device is designed to study the erosion-corrosion characteristics of 90° steel elbow in the gas-liquid-solid three-phase flow. A total of 28 group experiments are designed including 4 gas velocities, 3 liquid pH values, and 150 μm average sand particles. Moreover, a numerical simulation model is built based on the FLUENT code to predict the erosion-corrosion behavior. Experimental and simulation results show that the most severe erosion-corrosion region of the pipe bend occurs at the axial angle of the elbow between 20° and 50° and at the radial angle of the elbow between −45° and 45°. At the bottom of the elbow and the outer wall surface close to the outlet, the synergistic effect of erosion and corrosion accelerates the wear of the pipeline, but the opposite phenomenon exists at the position of the elbow with an axial angle of 50–70°.