Reducing THI Injection and Gas Hydrate Agglomeration by Under-Inhibition of Crude Oil Systems

2021 ◽  
Author(s):  
Jose G. Delgado-Linares ◽  
Ahmad A.A. Majid ◽  
Luis E. Zerpa ◽  
Carolyn A. Koh
Keyword(s):  
High Pressure ◽  
Crude Oil ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Management Strategies ◽  
Crude Oils ◽  
Flow Assurance ◽  
Natural Surfactants ◽  
The One ◽  
Assurance Problem

Abstract Gas hydrates constitute a serious flow assurance problem. Over the last decades, industry has faced this problem by using avoidance methods (e.g. injection of thermodynamic hydrate inhibitors) and management strategies (e.g. addition of hydrate anti-agglomerants). In the former, hydrates are completely avoided by shifting the hydrate boundary towards higher pressure and lower temperatures; in the latter, hydrates are allowed to form but their tendency to agglomerate is reduced. It should be noted that some crude oils are naturally able to avoid hydrate agglomeration, this non-plugging tendency may originate from the surfactant-like behavior of fractions like asphaltenes and acids. Recent works have shown that the natural non-plugging potential of certain oils can be affected by the addition of polar molecules like alcohols. There is another strategy for managing hydrate that consist of the addition of THIs at a concentration lower that the one required to full hydrate inhibition. In this case, hydrates are under-inhibited. Studies carried out on hydrate agglomerating systems have shown that under-inhibition might prevent hydrate agglomeration only in a specific range of THI concentrations and sub-cooling; however, work on non-plugging oils is scarce. In this paper, the hydrate agglomeration of two crude oils under-inhibited with methanol and MEG was evaluated through a visual rocking cell apparatus and a high-pressure rheometer. Results showed that THIs and the crude oil's natural surfactants were capable of acting synergistically in reducing hydrate agglomeration and improving the system flowability.

Hydrate Agglomeration in Crude Oil Systems in Which the Asphaltene Aggregation State Is Artificially Modified

SPE Journal ◽  
2020 ◽  
pp. 1-11
Author(s):  
Davi Costa Salmin ◽  
Jose G. Delgado-Linares ◽  
David T. Wu ◽  
Luis E. Zerpa ◽  
Carolyn A. Koh
Keyword(s):  
Crude Oil ◽  
Gas Hydrate ◽  
Management Strategies ◽  
Crude Oils ◽  
Aggregation State ◽  
Bulk Oil ◽  
Naturally Occurring ◽  
New Findings ◽  
Crude Oil Fractions ◽  
External Interventions

Summary Some crude oils contain naturally occurring surfactants that avoid hydrate agglomeration. Natural hydrate antiagglomeration has been linked to different crude oil fractions, including asphaltenes. Asphaltenes can promote the formation of stable water-in-oil (W/O) emulsions due to their amphiphilic properties. The surfactant-like behavior of asphaltenes is related to their aggregation state. Asphaltenes are strong emulsifying agents when in an aggregated state but weak emulsifying agents when either precipitated or well solubilized in the bulk oil phase. The asphaltene aggregation state may be artificially modified, changing its interfacial activity, by mixing crude oil with heptane–toluene mixtures. This work investigated the influence of the asphaltene aggregation state on gas hydrate agglomeration. Results show that the natural hydrate antiagglomerant properties of crude oils can be highly dependent on the artificially induced asphaltene aggregation state. For instance, if asphaltenes were induced to be solubilized into the bulk oil phase, the natural hydrate antiagglomerant behavior was diminished. However, when asphaltene aggregation was induced, gas hydrate agglomeration was avoided. These new findings could have significant implications for the implementation of novel hydrate management strategies that can reduce or eliminate the need for external interventions and hence minimize capital and operational expenditures by taking advantage of the intrinsic natural antiagglomerant properties of some crude oils.

Surface Treatment Strategies for Mitigating Gas Hydrate & Asphaltene Formation, Growth, and Deposition in Flowloops

2021 ◽  
Author(s):  
Marshall A Pickarts ◽  
Jose Delgado-Linares ◽  
Erika Brown ◽  
Vinod Veedu ◽  
Carolyn A. Koh
Keyword(s):  
High Pressure ◽  
Crude Oil ◽  
Surface Treatment ◽  
Memory Effect ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Flow Assurance ◽  
Stainless Steel Surface ◽  
Pipe Surface

Abstract Numerous solids including gas hydrates, waxes, and asphaltenes have the potential to form in the production lines of gas and oil fields. This creates a highly non-ideal scenario as the accumulation of said species leads to flow assurance issues, especially with long-term processes like deposition. Since an ever-increasing amount of material is deposited in place at the pipe surface, production stoppage or active mitigation efforts become inevitable. The latter production issues result in increased safety risks and operational expenditures. Therefore, a cost-effective, passive deposition mitigation technology, such as a pipeline coating or surface treatment is especially appealing. The ability to address multiple pipeline flow assurance issues simultaneously without actively disrupting production would represent a dramatic step forward in this area. This study is part of a long-term ongoing effort that evaluates the performance and application of an omniphobic surface treatment for solids deposition prevention in industrially relevant systems. In particular, this specific work concentrates on the efficacy and robustness of the treatment under fully flowing conditions. The apparatuses utilized for this include two flowloops: a lab-scale, high-pressure flowloop for gas hydrate and surface treatment durability studies, and a bench-scale, atmospheric pressure loop for crude oil and asphaltene experiments. Film growth in high-pressure flowloop tests corroborated previous reports of delayed gas hydrate nucleation observed in rocking cells. Without the aid of the memory effect, treated oil-dominated experiments never experienced hydrate formation, spending upwards of a week in the hydrate stability zone (at the subcooled/fluid test conditions). Subsequent tests which utilized the memory effect then revealed that the hydrate formation rate reduced in the presence of the surface treatment compared to a bare stainless-steel surface. This testing was part of a larger set of trials conducted in the flowloop, which lasted about one year. The surface treatment durability under flowing conditions was evaluated during this time. Even after experiencing ∼4000 operating hours and 2 full pressure cycles, no evidence of delamination or damage was detected. Finally, as part of an extension to previous work, corroded surface asphaltene deposition experiments were performed in a bench-top flowloop. Treated experiments displayed an order of magnitude reduction in both total oil (all fractions of crude oil) and asphaltene fraction deposited.

scholarly journals Investigation on Gas Hydrates Formation and Dissociation in Multiphase Gas Dominant Transmission Pipelines

2020 ◽  
Vol 10 (15) ◽  
pp. 5052 ◽  
Author(s):  
Sayani Jai Krishna Sahith ◽  
Srinivasa Rao Pedapati ◽  
Bhajan Lal
Keyword(s):  
Crude Oil ◽  
Phase Behavior ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Formation Rate ◽  
Water System ◽  
Hydrate Formation ◽  
Multiphase System ◽  
Gas Hydrate Formation ◽  
Water Cut

In this work, a gas hydrate formation and dissociation study was performed on two multiphase pipeline systems containing gasoline, CO2, water, and crude oil, CO2, water, in the pressure range of 2.5–3.5 MPa with fixed water cut as 15% using gas hydrate rocking cell equipment. The system has 10, 15 and 20 wt.% concentrations of gasoline and crude oil, respectively. From the obtained hydrate-liquid-vapor-equilibrium (HLVE) data, the phase diagrams for the system are constructed and analyzed to represent the phase behavior in the multiphase pipelines. Similarly, induction time and rate of gas hydrate formation studies were performed for gasoline, CO2, and water, and crude oil, CO2, water system. From the evaluation of phase behavior based on the HLVE curve, the multiphase system with gasoline exhibits an inhibition in gas hydrates formation, as the HLVE curve shifts towards the lower temperature and higher-pressure region. The multiphase system containing the crude oil system shows a promotion of gas hydrates formation, as the HLVE curve shifted towards the higher temperature and lower pressure. Similarly, the kinetics of hydrate formation of gas hydrates in the gasoline system is slow. At the same time, crude oil has a rapid gas hydrate formation rate.

scholarly journals A New Inhibitor to Prevent Hydrate Formation

2021 ◽  
Vol 5 (1) ◽  
pp. 1-6
Author(s):  
Bazvand M
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Deep Sea ◽  
Hydrate Formation ◽  
Cost Effective ◽  
Vinyl Pyrrolidone ◽  
Flow Assurance ◽  
Main Structure ◽  
Poly Vinyl Pyrrolidone ◽  
Prevention Methods

Due to the growing demand for energy as well as the depletion of shallow land reservoirs, it sounds more important to utilize deep sea reservoirs. Due to their special conditions, drilling and production of these reservoirs face more problems. The science that helps us avoiding problems during operation is called flow assurance. One of the important issues in flow assurance is to prevent formation of gas hydrates. One of gas hydrates preventing methods is to use of inhibitors. Using of inhibitors is a cost- effective and eco-friendly method; so, it is used more nowadays. This paper introduces a new hydrate inhibitor that has been developed from the modification of one of the most widely used inhibitors present in the industry, Poly Vinyl Pyrrolidone, to improve its efficiency. The main structure of the paper is about what is the gas hydrate and its prevention methods. Finally, compare different inhibitors with new one. The results show that hydrate formation time for all polymers is approximately the same, while a half of new inhibitor in compare with amount of others inhibitors causes the same results. This matter shows a double efficiency, and this means a saving of double Polymer consumption.

The Impact of the Composition of the Crude Oils on the Wax Crystallization

2014 ◽  
Vol 625 ◽  
pp. 196-200 ◽  
Author(s):  
Arya Hosseinipour ◽  
Khalik M. Sabil ◽  
Andhy Arya Ekaputra ◽  
Azuraien B. Japper ◽  
Lukman B. Ismail
Keyword(s):  
Differential Scanning Calorimetry ◽  
High Pressure ◽  
Crude Oil ◽  
Crude Oils ◽  
Solubility Curve ◽  
Scanning Calorimetry ◽  
Wax Precipitation ◽  
Wax Appearance Temperature ◽  
Wax Crystallization ◽  
The Impact

One of the major problems in petroleum industry is wax precipitation and deposition. The component’s compositional and structural analysis of the crude oils is key factors to be studied to mitigate wax formation and precipitation tendency for the betterment of the crude oil flowability. In this work, the compositions and structures of two Malaysian and Sudanese crude oil samples were determined to investigate their effects on wax precipitation. The GC/MS was used to analyze hydrocarbon components. For this work, high pressure micro differential scanning calorimetry (HPμDSC) is used to determine the wax crystallization point and solubility curve. Results showed a linear relationship between wax appearance temperature (WAT) and weight percentage of component in the crude oil having > 14 carbon atoms. In addition, the effect of temperature on the amount of wax precipitation has also been investigated. Keywords: N-paraffin, Wax appearance temperature, Wax precipitation, High pressure micro differential scanning calorimetry

scholarly journals Study on the decomposition mechanism and kinetic model of natural gas hydrate slurry in water-in-oil emulsion flowing systems

RSC Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 3879-3889
Author(s):  
Xiaofang Lv ◽  
Yang Liu ◽  
Shidong Zhou ◽  
Bohui Shi ◽  
Kele Yan
Keyword(s):  
Kinetic Model ◽  
Natural Gas ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Decomposition Mechanism ◽  
Flow Assurance ◽  
Natural Gas Hydrate ◽  
Oil Emulsion ◽  
Natural Gas Hydrates ◽  
Water In Oil Emulsion

Hydrate slurry decomposition in flow systems is a significant subject that involves flow assurance and development of marine natural gas hydrates.

Ethylene Glycol as Gas Hydrate Stabilising Substance

2015 ◽  
Author(s):  
Anne Schulz ◽  
Heike Strauß
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Ethylene Glycol ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Methane Hydrate ◽  
Sea Water ◽  
Drilling Fluid ◽  
Sodium Dodecyl ◽  
Gas Hydrate Formation

Gas hydrates are solid substances consisting of water and gas which are stable under high pressure and low temperature conditions. After Davy discovered chlorine hydrate in 1810, gas hydrates from natural gas were found to be the reason for gas pipeline plugging in 1934 by Hammerschmidt. In 1965, the Russian scientist Makogon discovered natural gas hydrate deposits. This was the beginning of research in the geological occurrence of the gas hydrates. Today, hundreds of gas hydrate wells for exploration have been drilled all over the world in the permafrost and deep sea regions. Several big projects for gas hydrate research and exploration have been financed by Japan, India, Korea, China and the USA. It is assumed that the amount of carbon in natural gas hydrates is twice the amount present in oil, gas and coal together. This makes them interesting as a future energy source. To drill into horizontal layers filled with gas hydrates in the pores, directional wells are needed. To achieve an adequate cutting transport, a high performance drilling fluid has to be used instead of sea water. The drilling fluid must be able to keep the gas hydrate reservoir stable while drilling and prevent the formation of secondary gas hydrates in the liquid. Moreover, the gas hydrate cuttings should not dissociate on their way to the surface. To avoid altering of the drilling fluid due to water and gas produced as a result of gas hydrate dissociation, cuttings should be kept stable to separate them from the fluid like any other rock cuttings by the surface equipment. To prevent gas hydrate formation, thermodynamic inhibitors, like salt, glycols or methanol are used. Also, kinetic inhibitors are added to the drilling fluid to prevent gas hydrate agglomeration and formation for a period of time. Well known kinetic inhibitors are polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and polyvinylcaprolactam (PVCap). Although ethylene glycol (EG) is seen as a thermodynamic inhibitor for gas hydrates, it is shown in this study that it is able to stabilize methane hydrate significantly. For the investigation, a high pressure cell with pressures up to 8.5 MPa was used. The equilibrium point of methane hydrate was detected. Solutions with PVP, PEG, hydroxyethylcellulose (HEC), Sodium dodecyl sulfate (SDS) and a kinetic inhibitor containing EG were tested (concentrations from 1 to 10 wt.‰). PVP, PEG and HEC could not stabilize gas hydrates at the test condition. SDS showed both a stabilizing and promoting effect. EG can significantly stabilize gas hydrates.

Study of the Effect of Crude Oils on the Metallic Corrosion

2018 ◽  
Vol 5 (1) ◽  
pp. 43-54
Author(s):  
Suresh Aluvihara ◽  
Jagath K Premachandra
Keyword(s):  
Crude Oil ◽  
Sulfur Content ◽  
Salt Content ◽  
Ferrous Metal ◽  
Relative Weight ◽  
Oil Refining ◽  
Crude Oils ◽  
Hardness Tester ◽  
Corrosion Rates ◽  
Ferrous Metals

Corrosion is a severe matter regarding the most of metal using industries such as the crude oil refining. The formation of the oxides, sulfides or hydroxides on the surface of metal due to the chemical reaction between metals and surrounding is the corrosion that  highly depended on the corrosive properties of crude oil as well as the chemical composition of ferrous metals since it was expected to investigate the effect of Murban and Das blend crude oils on the rate of corrosion of seven different ferrous metals which are used in the crude oil refining industry and investigate the change in hardness of metals. The sulfur content, acidity and salt content of each crude oil were determined. A series of similar pieces of seven different types of ferrous metals were immersed in each crude oil separately and their rates of corrosion were determined by using their relative weight loss after 15, 30 and 45 days. The corroded metal surfaces were observed under the microscope. The hardness of each metal piece was tested before the immersion in crude oil and after the corrosion with the aid of Vicker’s hardness tester. The metallic concentrations of each crude oil sample were tested using atomic absorption spectroscopy (AAS). The Das blend crude oil contained higher sulfur content and acidity than Murban crude oil. Carbon steel metal pieces showed the highest corrosion rates whereas the stainless steel metal pieces showed the least corrosion rates in both crude oils since that found significant Fe and Cu concentrations from some of crude oil samples. The mild steel and the Monel showed relatively intermediate corrosion rates compared to the other types of ferrous metal pieces in both crude oils. There was a slight decrease in the initial hardness of all the ferrous metal pieces due to corrosion.

Thermodynamic Modelling of Gas Hydrate Formation in the Presence of Inhibitors and the Consideration of their Effect

2014 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Peyman Sabzi ◽  
Saheb Noroozi
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Low Temperatures ◽  
Hydrate Formation ◽  
Transportation Systems ◽  
Flow Lines ◽  
Main Approach ◽  
Efficient Inhibitor ◽  
System A ◽  
Gas Hydrate Formation

Gas hydrates formation is considered as one the greatest obstacles in gas transportation systems. Problems related to gas hydrate formation is more severe when dealing with transportation at low temperatures of deep water. In order to avoid formation of Gas hydrates, different inhibitors are used. Methanol is one of the most common and economically efficient inhibitor. Adding methanol to the flow lines, changes the thermodynamic equilibrium situation of the system. In order to predict these changes in thermodynamic behavior of the system, a series of modelings are performed using Matlab software in this paper. The main approach in this modeling is on the basis of Van der Waals and Plateau's thermodynamic approach. The obtained results of a system containing water, Methane and Methanol showed that hydrate formation pressure increases due to the increase of inhibitor amount in constant temperature and this increase is more in higher temperatures. Furthermore, these results were in harmony with the available empirical data.Keywords: Gas hydrates, thermodynamic inhibitor, modelling, pipeline blockage

scholarly journals Linkages between Energy Delivery and Economic Growth from the Point of View of Sustainable Development and Seaports

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4255
Author(s):  
Elżbieta Szaruga ◽  
Zuzanna Kłos-Adamkiewicz ◽  
Agnieszka Gozdek ◽  
Elżbieta Załoga
Keyword(s):  
Sustainable Development ◽  
Crude Oil ◽  
Cross Correlation ◽  
Point Of View ◽  
Oil Products ◽  
Modern Approach ◽  
Economic Cycles ◽  
Study Results ◽  
The One ◽  
Oil And Oil Products

This paper presents the synchronisation of economic cycles of GDP and crude oil and oil products cargo volumes in major Polish seaports. On the one hand, this issue fits into the concept of sustainable development including decoupling; on the other hand, the synchronisation may be an early warning tool. Crude oil and oil products cargo volumes are a specific barometer that predicts the next economic cycle, especially as they are primary sources of energy production. The research study applies a number of TRAMO/SEATS methods, the Hodrick–Prescott filter, spectral analysis, correlation and cross-correlation function. Noteworthy is the modern approach of using synchronisation of economic cycles as a tool, which was described in the paper. According to the study results, the cyclical components of the cargo traffic and GDP were affected by the leakage of other short-term cycles. However, based on the cross-correlation, it was proved that changes in crude oil and oil products cargo volumes preceded changes in GDP by 1–3 quarters, which may be valuable information for decision-makers and economic development planners.

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