Gas Gathering Research Articles

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.

An Automatic Pointer Meter Reading Method based on Deep Learning in Gas Gathering Station

pointer meters are widely used in gas gathering stations, and manual meter reading is time-consuming and laborious. This paper proposes an automatic reading method of pointer meters in gas gathering stations based on deep learning and image processing algorithm. Firstly, the input image is detected by YOLO neural network algorithm to quickly locate the position of the pointer meter in the image; then, the meter image is segmented from the background image, and after filtering and binarization preprocessing, the meter border is preliminarily detected by Hough transform. After further removing the background interference, the pointer area and scale value area are segmented by connected domain detection to detect. After measuring the center of mass of the scale value area, the center of the dial is corrected again by RANSAC fitting circle, and the pointer angle is identified by index table thinning algorithm, and finally the meter indication is calculated. The results show that this method can quickly locate the pointer meters in the gas gathering station under complex background and reduce the light interference.

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.

Study on Ground Engineering and Management of Carbonate Oil Field A under Rolling Development Mode

Carbonate rock has the characteristics of complicated accumulation rules, large-scale development, high yield but unstable production. Therefore, the management and control of surface engineering projects of carbonate rock oil and gas reservoirs faces huge difficulties and challenges. The construction of surface engineering should conform to the principle of integrated underground and ground construction and adapt to the oilfield development model. This paper takes the newly added area A of the carbonated oil field as an example to study the ground engineering under the rolling development mode and aims to provide the constructive ideas for the surface engineering under rolling development mode. The overall regional process design adheres to the design concept of "environmental protection, efficiency, and innovation", strictly follows the design specifications, and combines reservoir engineering and oil production engineering programs, oil and gas physical properties and chemical composition, product programs, ground natural conditions, etc. According to the technical and economic analysis and comparison of area A, this paper has worked out a suitable surface engineering construction, pipeline network layout and oil and gas gathering and transportation plan for area A. Some auxiliary management recommendations are also proposed in this paper, like sand prevention management and HSE management for carbonate reservoirs.

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...

Pyrolysis behavior of coal in a moving bed with baffled internals under different residence times

In view of the problems faced by a conventional moving bed coal pyrolysis process, such as the inability to deal with pulverized coal, low light tar yield, poor tar quality, etc., a moving bed pyrolysis process with baffled internals was developed to control heat and mass transfer of the gas-solid two-phase and the pyrolysis reaction process. The multi-stage gas gathering system can collect the oil and gas products released in different pyrolysis stages of coal in time. The pyrolysis behavior and product quality of Naomaohu coal at different temperatures and residence times were investigated. The results show that the baffle internals enhance heat and volatile matter transfer among particles, enabling it to process 0.4–6.0 mm pulverized coal. When pyrolysis temperature is 550°C and residence time is 3.0h, the pyrolysis tar yield reaches the highest 11.38%, which is 86.87% of the Gray-King assay yield, and the mass fraction of light components below 360°C in the tar fraction is 85.0%. With the extension of the residence time, the H2 volume fraction in the pyrolysis gas increases from 22.1% to 35.1%, and the CO volume fraction increases from 8.0% to 9.5%. Tar yield in the first and second layer reactors increases with increasing residence time, and the tar yield in the third and fourth layer reactors isobtained when the residence time is 2.0 h. As the number of beds increases, content of light components in the tar simulated distillation fraction increases; content of tar aliphatic hydrocarbon compounds decreases, and that of monocyclic aromatic hydrocarbons and bicyclic aromatic hydrocarbons gradually increases. Based on the above results, it provides technical support for large-scale industrial processing of small particle size pulverized coal, and preparation of higher yield and quality tar.

A Noisy-OR gate based fuzzy fault tree approach for micro-leakage evaluation of bolt-gasket-flange connection (BGFC)

In the natural gas gathering and transportation station, bolt-gasket-flange connection (BGFC) is the main connection mode, but due to its large number, the micro-leakage may result in serious consequences. For this reason, early BGFC micro-leakage evaluation can effectively assist decision-making and prevent the occurrence of accidents. To solve the problem of insufficient field data collection, we proposed a Noisy-OR gate based fuzzy fault tree approach, and calculated the corresponding minimum cut sets and the highest risk factors. Moreover, sensitivity analysis (SA) was used to determine that material problems (wear and corrosion of the sealing surface), man-made operation problems (bolts and flanges) and working conditions (pipe vibration and temperature fluctuations) are the key factors that contributing to the BGFC micro-leakage. In brief, the combination of the fuzzy fault tree analysis and Noisy-OR gate is an effective approach for BGFC micro-leakage evaluation, which is of great significance to the micro-leakage analysis, safe operation, and risk assessment of the gas station.

Integrity and cost evaluation of natural fibers/HDPE composite tailored for piping applications

This paper focused on the establishment of performance level and cost of plantain fibers reinforced High Density Polyethylene (HDPE) matrixes as gas pipeline material using pressure containment of the new materials as performance criterion. The cost of modified plantain fibers, the cost of plantain fibers reinforced HDPE (PFRHDPE) and the cost of PFRHDPE master batch (HDPE resin + plantain fiber particles + stabilizer, plasticizer) for pipes extrusion production and pipelines fittings injection productions were established. The burst pressure evaluated for available standard outside diameter ratio (SDR) using the ultimate tensile strength of PFRHDE is very much greater than the standard SDR design pressures even when the temperature derating factors were applied. The Maximum Allowable Operating Pressure (MAOP) of PFRHDPE and induced stresses of pressurized pipes established indicated that the new material is suitable for pipeline design for natural gas and liquid petroleum (LPG) lines. The PFRHDPE developed has better specific properties than the conventional steel and HDPE pipe material in terms of yield strength, elastic modulus and density of the new material. But in terms of cost, steel and HDPE has approximate desirability for selection with PFRHDPE. The energy required to manufacture and process steel products is about 480 MJ/m2, while that of plastics is about 320 MJ/m2. The study further established that PFRHDPE can be applied in the design of oil and gas gathering, transportation and distribution lines.

Failure Analysis on Leakage and Perforation of Natural Gas Pipeline

CO2 corrosion is one of the most common corrosion forms in the process of oil and gas field development and oil and gas gathering and transportation. In the process of natural gas gathering and transportation, the problem of pipeline corrosion caused by CO2 is widespread, which often leads to serious local thinning, even perforation and fracture of the pipe body. Once it occurs, it will cause great economic losses and disastrous consequences to the actual production. Therefore, it is of great practical significance to study the mechanism of CO2 corrosion and analyze the influencing factors of CO2 corrosion in order to prevent the safety accidents and improve the efficiency of natural gas transportation. In this paper, a natural gas pipeline wall perforation failure analysis as an example, the sample from the natural gas pipeline corrosion product morphology and composition of micro analysis, and the CO2 corrosion mechanism, influencing factors and other aspects are described in detail.

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°.

Study on Erosion Behavior and Separation Efficiency of a Shale Gas Vertical Separator

In a shale gas gathering and transportation station, the sand particles that are not separated by the upstream desander will cause erosion damage to the vertical separator. In response to this problem, based on the field data of a production well in the Changning area, the corresponding mathematical model and vertical separator geometric model were established. On the basis of the software FLUENT, the effects of different gas velocity, particle size, and sand mass flow on the erosion of the separator and the motion of particles were simulated. The corresponding results show that the erosion scar of the inlet baffle presents a ring shape, and the maximum erosion position on the wall changes with the increase of gas velocity. The erosion rate of the inlet baffle is proportional to the sand flow rate and geometrically related to the gas velocity; the maximum erosion rate of the vertical separator is 520 μm/a under the conditions of 6 kg/d sand input; the separation efficiency decreases with the increase of particle size and speed.

NSIL Evaluation and Sensitivity Study of Diverse Redundant Structure

In order to evaluate the safety integrity level (SIL) of safety instrumented systems (SIS) with diverse redundancy structures including more realistic assumptions, the average probability of failure on demand (PFDavg) models for the common diverse redundancy structures (1oo2, 2oo2, and 2oo3) have been established based on the fault tree analysis (FTA) method. These models take into account the common cause failures (CCF) and diagnostic coverage (DC) parameters with the correction coefficient. The model is applied to the SIL assessment of the emergency shutdown system (ESD) with diverse redundancy in gas storage and gathering. The proof test interval T is used as an indicator to compare and verify the sensitivity of both the new model and the previous models. The results can be concluded as follows: 1) The new model achieves higher consistency than the previous models; 2) The proposed model considers that different redundancy structures have CCF, which are more realistic and have higher applicability to be used to solve practical engineering problems.

In situ mathematically simulation for CO2 internal corrosion in wet natural gas gathering pipelines system by HYSYS

The rate of corrosion due to the presence of carbon dioxide in a carbon steel pipe is an important design consideration for gathering pipelines, particularly in the transport of wet natural gas. To evaluate the corrosion rate in a gathering pipeline, in situ simulation study using HYSYS program employed to predict CO2 corrosion in natural gas gathering pipelines system. The effects of operational conditions, inhibitors, pipe parameters and flow regime on the CO2 corrosion are studied in this paper. Increasing operating pressure leads to increase the pH and decrease the CO2 corrosion rate when the operating pressure over 10 MPa and the solution contents 0.85kmol/m3 iron carbonate. The CO2 corrosion rate does not always increase with temperature, and which will reach a maximum value at 45 °C. A high gas velocity will lead to a high corrosion rate. Less free water present in pipeline may lead to more serious corrosion than that of a large amount of free water. The corrosion rate may be inhibited by liquid hydrocarbon and glycol, and the glycol is not an economic inhibitor, especially when there is a large amount of free water in pipeline. The large diameter and flat pipe are useful for decreasing CO2 corrosion rate. The shear stress and corrosion rate will increase sharply when the slug flow forms in pipeline. Through comparing the data of simulation with field corrosion rate data, feasibility of this numerical simulation method is proved.

Application of Computer Energy Optimization Method in Oil and Gas Gathering and Transportation System

With the continuous development of society and economy, human demand for petrochemical-related products and derivatives is becoming more and more vigorous. However, the increase in oilfield development time and the expansion of scale easily make it difficult to control energy consumption. In response to this bottleneck problem, this paper relies on computer technology to explore the development of energy optimization software for oil and gas gathering and transportation systems, which provides convenience for grassroots technical managers by realizing control of the operating parameters of the oil gathering system, realizing process management and fine management., Changed the traditional oilfield management model. At the same time, taking the water-mixing oil collection process as an example, explore the application process and effect of the software in the oil field.

Research on Formation Prediction Model of Gas Hydrate

In the process of gas extraction, gathering and transportation, etc., the formation of hydrates will cause blockage of mining facilities and pipelines and affect normal production, and even there are hidden dangers, causing difficulties in gas development. Therefore, the building of the hydrate prediction model is an urgent problem to be solved in the prevention and control of hydrate; it plays an important role in accurately and efficiently predicting the specific position and time of hydrate formation. In this paper, The formation mechanism and conditions of gas hydrate were described, and the prediction models of hydrate were introduced from two aspects: whether there are inhibitors (alcohols and electrolytes) in the hydrate system, respectively, the VdW-P model, a series of thermodynamic models based on it, and Chen Guo model based on hydrate dynamics were mainly described. Under different application conditions, the appropriate prediction model can effectively predict the formation of hydrate.

Discussion on Water Dew Point and Hydrocarbon Dew Point of Natural Gas

During natural gas processing and gathering and transportation, water dew point and hydrocarbon dew point as two of control parameters in natural gas because of safety, economy and efficiency etc. In the field chilled mirror manual visual method always be taken to measure water and hydrocarbon dew point due to online instrument test under a differential condition from the pipeline. For hydrocarbon dew point, there’re some assays have implied that heavier components in natural gas have an important effect on hydrocarbon dew point, at the same time hydrocarbon dew point gained under the pressure between 2MPa~4MPa is equal to the max condensation temperature which has a practical meaning. On the other hand, the retrograde condensation cannot be ignored; for water dew point, application of molecular sieve would make dew point measurement easier, while application of dehydrating agents such as methanol; glycols and glycerol could cause interference, instruments &operators differences are exist, but the changing process is consistent when chilled down temperature. In this case, Attention should be given to a white fog which might appear on the center of the surface of the chilled mirror one or more times while temperature dropping down. At last some suggestions are given from two aspects of processing and measurement of water and hydrocarbon dew point.

Study on gas characterization and fluorescence characteristics of intermediates in biogenic gas production from lignite by ultrasound assisted hydrogen peroxide pretreatment

In order to improve the utilization efficiency of coal by microorganisms and increase gas production, ultrasound assisted hydrogen peroxide oxidation of lignite was studied. The changes of accumulated gas, methane content, carbon dioxide content, and fluorescence characteristics of intermediate products in lignite and oxidized lignite system were studied by drainage gas gathering method, gas chromatography (GC) and fluorescence spectrophotometer. It was found that the cumulative gas could be divided into three stages: rapid gas production, slow gas production, and basic stable stage. The methane production rate of raw coal and lignite treated by ultrasound assisted hydrogen peroxide reached 987.23 μmol/g and 1290.22 μmol/g, respectively. The methane yield for oxidized lignite was 30.69% higher than that of raw lignite. The ultrasonic-assisted hydrogen peroxide pretreatment for lignite could effectively increase methane production. The analysis results of the fluorescence characteristics of the intermediates indicated that the total fluorescence intensity (FI) integral of intermediates decreased with the increase of time. The fluorescence peak positions mainly changed in tyrosine aromatic proteins and soluble microbial metabolites. Ultrasound-assisted hydrogen peroxide pretreatment lignite changed the amount of tyrosine-based aromatic proteins, hydrophobic organic acid fulvic acid, humic acids, and soluble microbial metabolites in the slow and stable stages of lignite biogas.

Reliability analysis of gas pipeline with corrosion defect based on finite element method

PurposeGas pipelines are facing serious risk because of the factors such as long service life, complex working condition and most importantly, corrosion. As one of the main failure reasons of gas pipeline, corrosion poses a great threat to its stable operation. Therefore, it is necessary to analyze the reliability of gas pipelines with corrosion defect. This paper uses the corresponding methods to predict the residual strength and residual life of pipelines.Design/methodology/approachIn this paper, ASME-B31G revised criteria and finite element numerical analysis software are used to analyze the reliability of a special dangerous section of a gas gathering pipeline, and the failure pressure and stress concentration of the pipeline under three failure criteria are obtained. Furthermore, combined with the predicted corrosion rate of the pipeline, the residual service life of the pipeline is calculated.FindingsThis paper verifies the feasibility of ASME-B31G revised criteria and finite element numerical analysis methods for reliability analysis of gas pipelines with corrosion defect. According to the calculation results, the maximum safe internal pressure of the pipeline is 9.53 Mpa, and the residual life of the pipeline under the current operating pressure is 38.41 years, meeting the requirements of safe and reliable operation.Originality/valueThe analysis methods and analysis results provide reference basis for the reliability analysis of corroded pipelines, which is of great practical engineering value for the safe and stable operation of natural gas pipelines.