scholarly journals Characterization of Physical Field and Flow Assurance Risk Analysis of Subsea Cage-Sleeve Throttling Valve

2021 ◽  
Vol 9 ◽  
Author(s):  
Donglei Jiang ◽  
Wenbo Meng ◽  
Yi Huang ◽  
Yi Yu ◽  
Youwei Zhou ◽  
...  
Keyword(s):  
Low Temperature ◽  
Production System ◽  
Oil And Gas ◽  
Negative Impact ◽  
Hydrate Formation ◽  
Simulation Method ◽  
Gas Production ◽  
Oil And Gas Development ◽  
Regular Production ◽  
Subsea Production System

The subsea production system is presently widely adopted in deepwater oil and gas development. The throttling valve is the key piece of equipment of the subsea production system, controlling the safety of oil and gas production. There are many valves with serious throttling effect in the subsea X-tree, so the hydrate formation risk is relatively high. In this work, a 3D cage-sleeve throttling valve model was established by the numerical simulation method. The temperature and pressure field of the subsea throttling valve was accurately characterized under different prefilling pressure, throttling valve opening degree, and fluid production. During the well startup period, the temperature of the subsea pipeline is low. If the pressure difference between the two ends of the pipeline is large, the throttling effect is obvious, and low temperature will lead to hydrate formation and affect the choice of throttling valve material. Based on the analysis of simulation results, this study recommends that the prefilling pressure of the subsea pipe is 7–8 MPa, which can effectively reduce the influence of the throttling effect so that the downstream temperature can be kept above 0°C. At the same time, in regular production, a suitable choke size is opened to match the production, preventing the serious throttling effect from a small choke size. According to the API temperature rating table, the negative impact of local low temperature caused by the throttling effect on the temperature resistance of the pipe was considered, and the appropriate subsea X-tree manifold material was selected to ensure production safety. The hydrate phase equilibrium curve is used to estimate the hydrate formation risk under thermodynamic conditions. Hydrate inhibitors are injected to ensure downstream flow safety.

Proxy Model for Real-Time Estimation of Cool Down Time of Subsea Production System to Prevent Hydrates Formation

2021 ◽  
Author(s):  
Joseph Rizzo Cascio ◽  
Antonio Da Silva ◽  
Martino Ghetti ◽  
Martino Corti ◽  
Marco Montini
Keyword(s):  
Real Time ◽  
Production System ◽  
Field Data ◽  
Oil And Gas ◽  
Time Estimation ◽  
Integrated Approach ◽  
Proxy Model ◽  
Real Time Estimation ◽  
Subsea Production System ◽  
Formation Of Hydrates

Abstract Objectives/Scope The benefits of real-time estimation of the cool down time of Subsea Production System (SPS) to prevent formation of hydrates are shown on a real oil and gas facility. The innovative tool developed is based on an integrated approach, which embeds a proxy model of SPS and hydrate curves, exploiting real-time field data from the Eni Digital Oil Field (eDOF, an OSIsoft PI based application developed and managed by Eni) to continuously estimate the cool down time before hydrates are formed during the shutdown. Methods, Procedures, Process The Asset value optimization and the Asset integrity of hydrocarbon production systems are complex and multi-disciplinary tasks in the oil and gas industry, due to the high number of variables and their synergy. An accurate physical model of SPS is built and, then, used to develop a proxy model, which integrates hydrate curves at different MeOH concentration, being able to estimate in real time the cool down time of SPS during the shutdown exploiting data from subsea transmitters made available by eDOF in order to prevent formation of hydrates. The tool is also integrated with a user-friendly interface, making all relevant information readily available to the operators on field. Results, Observations, Conclusions The integrated approach provides a continues estimation of cool down time based on real time field data (eDOF) in order to prevent formation of hydrates and activate preservation actions. An accurate physical model of SPS is built on a real business case using Olga software and cool down curves simulated considering different operating shutdown scenarios. Hydrate curves of the considered production fluid are also simulated at different MeOH concentration using PVTsim NOVA software. Off-line simulated curves are then implemented as numerical tables combined with eDOF data by an Eni developed fast executing proxy model to produce estimated cool down time before hydrates are formed. A graphic representation of SPS behavior and its cool down time estimation during shutdown are displayed and ready to use by the operators on field in support of the operations, saving cost and time. Novel/Additive Information The benefits of real time estimation of the cool down time of SPS to prevent hydrates formation are shown in terms of saving of time and cost during the shutdown operations on a real case application. This integrated approach allows to rely on a continue, automatic and acceptably accurate estimate of the available time before hydrates are formed in SPS, including the possibility to be further developed for cases where subsea transmitters are not available or extended to other flow assurance issues.

scholarly journals A Novel Low-Temperature Non-Corrosive Sulfate/Sulfide Scale Dissolver

2020 ◽  
Vol 12 (6) ◽  
pp. 2455
Author(s):  
Hany Gamal ◽  
Salaheldin Elkatatny ◽  
Dhafer Al Shehri ◽  
Mohamed Bahgat
Keyword(s):  
Low Temperature ◽  
Corrosion Rate ◽  
High Performance ◽  
Oil And Gas ◽  
Ethylenediaminetetraacetic Acid ◽  
Gas Production ◽  
Operating Conditions ◽  
Superior Performance ◽  
X Ray ◽  
Dissolution Efficiency

The oil and gas production operations suffer from scale depositions. The scale precipitations have a damaging impact on the reservoir pores, perforations, downhole and completion equipment, pipeline network, wellhead chokes, and surface facilities. Hydrocarbon production possibly decreased because of the scale accumulation in the well tubular, leading to a well plugging, this requires wells to be shut-in in severe cases to perform a clean-out job. Therefore, scale deposition is badly affecting petroleum economics. This research aims to design a scale dissolver with low cost, non-damaging for the well equipment and has a high performance at the field operating conditions. This paper presents a novel non-corrosive dissolver for sulfate and sulfide composite scale in alkaline pH and works at low-temperature conditions. The scale samples were collected from a production platform from different locations. A complete description of the scale samples was performed as X-ray diffraction (XRD) and X-ray fluorescence (XRF). The new scale dissolver was prepared in different concentrations to examine its dissolution efficiency for the scale with time at low temperatures. The experimental design studied the solid to fluid ratio, temperature, solubility time, and dissolution efficiency in order to achieve the optimum and most economic performance of solubility in terms of high dissolution efficiency with the smallest possible amount of scale dissolver. A solubility comparison was performed with other commercial-scale-dissolvers and the corrosion rate was tested. The experimental work results demonstrated the superior performance of the new scale dissolver. The new scale dissolver showed a solubility efficiency of 91.8% at a low temperature of 45 °C and 79% at 35 °C. The new scale dissolver showed a higher solubility ratio for the scale sample than the ethylenediaminetetraacetic acid (EDTA) (20 wt. %), diethylenetriamine pentaacetic acid (DTPA) (20 wt. %), and HCl (10 wt. %). The corrosion rate for the new non-corrosive dissolver was 0.01357 kg/m2 (0.00278 lb./ft²) which was considered a very low rate and non-damaging for the equipment. The low corrosive effect of the new dissolver will save the extra cost of adding the corrosion inhibitors and save the equipment from the damaging effect of the corrosive acids.

Risk Assessment of Subsea X-Tree System

2011 ◽  
Vol 148-149 ◽  
pp. 1000-1006 ◽  
Author(s):  
Chang Yong Wang ◽  
Hong Huan Zhang ◽  
Meng Lan Duan
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Reliability Analysis ◽  
Deep Water ◽  
Production System ◽  
Oil And Gas ◽  
Oil And Gas Exploration ◽  
Analysis Process ◽  
Subsea Production System ◽  
Exploration And Development

That the oil and gas exploration and development is extending into deep water proceeds the rapidly shift to subsea production system. However, complex subsea equipment and frequency offshore accidents aroused the concern on the risk assessment of subsea system. The paper illustrates the hazard aspects which should be focused on in the subsea equipment compared with the surface equipment. The hazards identification and risk analysis on subsea X-tree system is carried out. A general risk-prevent process of subsea X-tree system is illustrated, so does the reliability analysis process. Besides, some commendations on subsea detection and maintenance are presented in the paper.

Development and Application of a New Style Low Dosage Hydrate Inhibitors

2014 ◽  
Author(s):  
Weixin Pang ◽  
Qingping Li ◽  
Fujie Sun
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
South China Sea ◽  
Field Test ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Effective Technology ◽  
Low Dosage

The hydrate is an important issue that the flow assurance has to face in the oil and gas industry, especially in the deepwater area. With high pressure and low temperature, the hydrate formation is easily happened and leads to plug in the pipeline. In addition to the traditional thermodynamic inhibitor, the low dosage hydrate inhibitors (LDHI) has been increasing used as a costly effective technology for gas hydrate control. The LDHI include kinetic hydrate inhibitor (KHI) and anti-agglomerant (AA), the former can inhibit the hydrate formation in the pipeline, and the latter can prevent the agglomeration and plug of hydrate particles. According to the properties of oil and gas of South China Sea, a new KHI and AA were developed, a field test of the KHI has been undertaken and the results indicate that it can prevent the hydrate formation and plug in the pipeline well, the lab evaluation of the developed AA is in progress and the field test will be performed by the next year.

scholarly journals The Assessment of the Impact of Sanctions on Russia for Oil & Gas Industry and Defence Industry Complex of Russia

2019 ◽  
Vol 12 (3) ◽  
pp. 46-57 ◽  
Author(s):  
S. V. Kazantsev
Keyword(s):  
Oil And Gas ◽  
Negative Impact ◽  
Financial Economic ◽  
Gas Production ◽  
Gas Industry ◽  
Oil And Gas Production ◽  
Foreign Earnings ◽  
Defence Industry ◽  
Wide Range ◽  
The Impact

The article presents the results of the author’s research of the impact of a wide range of restrictions and prohibitions applied to theRussian Federation, used by a number of countries for their geopolitical purposes and as a means of competition. The object of study was the impact of anti-Russian sanctions on the development of Oil & Gas industry and defence industry complex ofRussiain 2014–2016. The purpose of the analysis was to assess the impact of sanctions on the volume of oil and gas production, the dynamics of foreign earnings from the export of oil and gas, and of foreign earnings from the sale abroad of military and civilian products of the Russian defence industry complex (DIC). As the research method, the author used the economic analysis of the time series of statistical data presented in open statistics and literature. The author showed that some countries use the anti-Russian sanctions as a means of political, financial, economic, scientific, and technological struggle with the leadership ofRussiaand Russian economic entities. It is noteworthy that their introduction in 2014 coincided with the readiness of theUSto export gas and oil, which required a niche in the international energy market. The imposed sanctions have affected the volume of oil production inRussia, which was one of the factors of reduction of foreign earnings from the country’s oil and gas exports. However, the Russian defence industry complex has relatively well experienced the negative impact of sanctions and other non-market instruments of competition

Study on the Optimization of Hydrate Management Strategies in Deepwater Gas Well Testing Operations

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Shangfei Song ◽  
Bohui Shi ◽  
Weichao Yu ◽  
Lin Ding ◽  
Yang Liu ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Management Strategies ◽  
Hydrate Formation ◽  
Oil And Gas Industry ◽  
Gas Production ◽  
Optimal Dosage ◽  
Well Testing ◽  
Delayed Effect ◽  
Gas Well ◽  
Risk Margin

Abstract Low temperature and high pressure conditions favor the formation of gas clathrate hydrates which is undesirable during oil and gas industries operation. The management of hydrate formation and plugging risk is essential for the flow assurance in the oil and gas production. This study aims to show how hydrate management in the deepwater gas well testing operations in the South China Sea can be optimized. To prevent the plugging of hydrate, three hydrate management strategies are investigated. The first method, injecting thermodynamic hydrate inhibitor (THI) is the most commonly used method to prevent hydrate formation. THI tracking is utilized to obtain the distribution of mono ethylene glycol (MEG) along the pipeline. The optimal dosage of MEG is calculated through further analysis. The second method, hydrate slurry flow technology is applied to the gas well. Pressure drop ratio (PDR) is defined to denote the hydrate blockage risk margin. The third method is the kinetic hydrate inhibitor (KHI) injection. The delayed effect of KHI on the hydrate formation induction time ensures that hydrates do not form in the pipe. This method is effective in reducing the injection amount of inhibitor. The problems of the three hydrate management strategies which should be paid attention to in industrial application are analyzed. This work promotes the understanding of hydrate management strategies and provides guidance for hydrate management optimization in oil and gas industry.

Experimental Study and Prediction Model for Hydrate Plugging Formation in Single-Pass Gas-Dominated Pipes with Diameter Reduction

SPE Journal ◽  
2021 ◽  
pp. 1-19
Author(s):  
Jianbo Zhang ◽  
Zhiyuan Wang ◽  
Shengnan Chen ◽  
Jihao Pei ◽  
Nan Ma ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
Gas Production ◽  
Targeted Prevention ◽  
Oil And Gas Production ◽  
Single Pass ◽  
Hydrate Deposition ◽  
Constant Diameter ◽  
Diameter Reduction

Summary Gas hydrate plugging in flowlines acts as a major blockage risk in oil, gas, and natural gas hydrate production. Current studies on hydrate plugging is mainly conducted in pipes with a constant diameter, whereas the effects of varying diameters have been less explored. Pipes with diameter reductions are very common in the oil and gas production process. Herein, by performing experiments with pipes of four different sizes, including one with a constant diameter and three with diameter reductions, the hydrate plugging in single-pass gas-dominated pipes with diameter reduction is investigated systematically, the results of which show that the existence of diameter reduction can facilitate the deposition of hydrate particles on pipe walls and the formation of a hydrate deposition layer. Meanwhile, hydrate sloughing occurs during the growth of the hydrate deposition layer under fluid shear force. With the increase in the diameter reduction ratio or subcooling for hydrate formation, the hydrate deposition is observed to increase significantly, thus resulting in the reduction of time for hydrate plugging. According to these results, the hydrate plugging mechanism in pipes with diameter reduction is proposed. Further, in combination with the hydrate deposition difference between the inside and outside of the arc-shaped low-speed area, a new numerical model is established for hydrate plugging prediction in the pipe with diameter reduction, which can predict the growth and evolution of the hydrate deposition layer accurately with the consideration of the diameter’s reduction. The results of this work provide a valuable guidance for the targeted prevention and management of hydrate plugging in flowlines with diameter reductions.

Influence of an energy factor on the relations between Azerbaijan and Russia

2018 ◽  
pp. 121-141
Author(s):  
Roman Temnikov
Keyword(s):  
Soviet Union ◽  
Oil And Gas ◽  
Negative Impact ◽  
Gas Production ◽  
Soviet Republic ◽  
Oil And Gas Production ◽  
Energy Factor ◽  
The Soviet Union ◽  
Hard Times

The relations between Azerbaijan and Russia have deep historical roots. For about two centuries they have been part of common state – Russian empire and the Soviet Union. Such cohabitation in the frames of one state had led to emergence of common features in development of two societies. One of these features is an important role of oil and gas production in economy. But despite of this similarity the Azerbaijani-Russian relations were not always benevolent. First of all, Azerbaijan for almost two centuries had been under Russian occupation. Even after dissolution of the USSR the relations of the former center – Moscow with the former Soviet republic which restored the independence – Azerbaijan, remained difficult. Practically from the first years of independence energy factor in the Azerbaijani-Russian relations has had the negative impact on already tense relations between two countries. During the modern period, after the beginning of gas production on new fields in Azerbaijan and after completion of the Southern gas corridor’ construction on delivery of the Azerbaijani gas to Europe, the Azerbaijani-Russian relations will expect hard times again.

Offshore Oil and Gas: The Future Engineering Contribution

1974 ◽  
Vol 188 (1) ◽  
pp. 11-24 ◽  
Author(s):  
L. C. Allcock
Keyword(s):  
Continental Shelf ◽  
Oil And Gas ◽  
New Technology ◽  
Gas Production ◽  
Oil And Gas Development ◽  
Oil And Gas Production ◽  
The Future ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
Production Industry

Development of offshore oil and gas production from the continental shelf and in even deeper water will be dependent on engineers. It is of primary importance to understand the nature of the oil and gas production industry in order to follow more clearly the contribution that will be required from many of the professional branches of engineering, and a great deal of new technology must be developed in order that the problems of the future may be overcome. The difficulty may not be in defining the future engineering of oil and gas development but in finding engineers in sufficient numbers to meet the demand.

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