Stabilisation of Gaslift Production Using a Dynamic Simulator

2001 ◽  
Author(s):  
Yvonne V. Roberts ◽  
Matt Nicol
Keyword(s):  
Production Management ◽  
Mechanical Damage ◽  
Phase Changes ◽  
Fluid Composition ◽  
Remedial Action ◽  
Original Design ◽  
The North ◽  
Water Cut ◽  
The Impact ◽  
Gas Lift

Abstract A common problem with gas lifted wells is the development, over time, of instabilities in the injection/production behaviour. The question raised is initially that of “probable cause and effect”; the understanding of which is essential to the determination of possible remedial action. The major causes of unstable behaviour fall into three broad categories: • Design related - the original design is inappropriate or inflexible. • Mechanical - damage to, and/or failure of, valves and equipment. • Dynamic flow behaviour - changes in fluid composition and/or phase changes. Commonly, the instability incorporates elements from more than one category. This paper discusses one case in which a horizontal well in the North Sea, which had a gas lift completion designed for operation at a water cut of around 20%, exhibited unstable production after a rapid rise in water cut to approximately 80%. The paper shows how a new and unique dynamic gas lift simulator was used to reproduce the observed well behaviour, and how the model was then used to recommend remedial action to stabilise production. The impact of these remedial actions is discussed in the context of the overall production management. Finally, the implementation of the recommendations and the subsequent well behaviour are presented.

Comprehensive Approach to Tackle Systemic Failure in Gas Lift Valves in Pre Salt Wells

2021 ◽  
Author(s):  
Elaine Daniele M P C Real ◽  
Thiago Geraldo Silva ◽  
Otavio Borges Ciribelli ◽  
Tatiana Sanomya
Keyword(s):  
Failure Process ◽  
Comprehensive Approach ◽  
Fluid Composition ◽  
Artificial Lift ◽  
Production Wells ◽  
Production History ◽  
Early Failures ◽  
Water Cut ◽  
The Impact ◽  
Gas Lift

Abstract This work describes a comprehensive approach to tackle systemic failure in gas lift valves in pre-salt wells. Failure analyses in gas lift valves were performed after unexpected early failures leading to tubing-annulus communication. Understanding the root causes of this problem generates value for assets, increasing equipment life, preventing unnecessary workover, and reducing costs. Suspect failed valves are systematically removed from the wells, usually by slick-line workovers, and brought to an onshore workshop, where their integrity and mechanical functionality can be analyzed. The valve's run life, equipment model and manufacturer, annular fluid, flow through the gas lift valve, operational pressure and temperature, composition of reservoir fluids and solids deposition were verified. Besides, transient simulations were carried out to provide insights on the root causes of the failure. Also, a good understanding on how each valve works, including its engineering design, was necessary to thoroughly understand the failure process. The study of gas-lift injection valves early failure in pre-salt wells have been an excellent way to understand the life cycle of production wells before the need to start lift gas injection. That leads to a comprehensive understanding about the effects of the fluids left in annulus and have supported Petrobras in most effectively managing of well integrity and workover costs. The analysis incorporates the impact of oil production, water cut, completion type, annular fluid composition, anti-scaling fluid injection (composition and efficiency) and the differential pressure between the tubing of the annulus in the valve failure model. The composition of the deposit found inside the valves and the production history of the well were essential to assemble the puzzle of how the failure mechanism works. With the acquired knowledge, it has been possible to apply barriers to avoid future events of unwanted tubing-annulus communication arising from gas-lift valve failures. This article provides a methodology and examples for a most effective understanding of the gas-lift valves failure mechanisms and their root causes, which proved to be a valuable tool for the artificial lift design and for the planning of well operations. That has contributed to maximize equipment life, cost reduction and, at last, generating value for the company.

Integrated Asset Modeling in Mature Offshore Fields: Challenges and Successes

2014 ◽  
Author(s):  
R.. Nazarov ◽  
P.. Zalama ◽  
M.. Hernandez ◽  
C.. Rivas
Keyword(s):  
Production Management ◽  
Treatment Plant ◽  
Integrated Model ◽  
Production Optimization ◽  
Production Model ◽  
Peak Performance ◽  
Fluid Composition ◽  
Well Performance ◽  
System Pressure ◽  
Gas Lift

Abstract Production management in mature fields is a very challenging task which involves a multidisciplinary technical approach to minimize the decline rate and extend the life of the asset/field. Most of the time Integrated Asset Modeling (IAM) techniques are applied to green fields with main objectives of identifying the “bottlenecks” or to forecast production with different development cases. In the case of mature fields it is mostly considered as an optional study with less analytical value due to low operating surface pressures, already existing facilities, known well performance and studied reservoir geology. Nevertheless the processing of the reservoir, production and operational data in mature assets through one integrated workflow facilitates field management overall, thereby helping in the estimation of the remaining reserves and indicating real opportunities for optimization not seen by initial engineering scenarios. Additionally, IAM should be incorporated before getting to EOR studies. This paper describes the applied reservoir engineering workflow and integrated production model for the TSP fields (Teak, Samaan and Poui) located in the South East of Trinidad. TSP fields are jointly owned by by Repsol (70%), Petrotrin (15%) and NGC (15%) and are operated by Repsol. Current production of TSP is 13, 500 bopd. The oil produced from these fields is generally light oil, with an average range of 25-40 API and a solution GOR 200-1400scf/stb. Gas lift is the artificial lift system used in 95% of the wells. Average water cut is around 85%. Interaction of Production Engineering, Subsurface, Drilling, HSE, Facilities, and Maintenance departments is the key aspect to sustain the efficient operability of the TSP fields and operate at peak performance in spite of ageing installations, flow assurance problems and depleted reservoirs. The implementation of Operated Asset Structure in TSP in 2013 reinforced the cooperation between departments to achieve the main goals: minimum production deferrals, production optimization, screening of new opportunities and reserves, process improvement, facilities maintenance and effective logistics. Additionally, the Integrated Asset Modeling has been incorporated as part of the engineering surveillance which includes 3 fields, 100 wells, gas lift injection network, gas compressors, water treatment plant, etc. Real data from different sources and platforms, such as pressure temperature sensors, daily measured well parameters, reported operational figures, monthly welltests and screened remaining reserves are jointly transferred to the integrated model, built in commercial software (GAP/RESOLVE), bringing the field data processing and production management to the state-of-the-art level. Gas lift volume availability and system pressure, performed rigless intervention jobs (including recompletion of new zones), change of the fluid composition in certain wells, reconfiguration of facilities are timely reflected in the TSP integrated model. Based on the sensitivity runs and output results immediate actions are taken to comply with the production target.

Nachhaltigkeit im Wald – vor und hinter der Welle der Globalisierung | Sustainable Forest Management – In Front and Behind the Wave of Globalization

2000 ◽  
Vol 151 (12) ◽  
pp. 502-507
Author(s):  
Christian Küchli
Keyword(s):  
Forest Management ◽  
Cultural Landscape ◽  
Sustainable Forest Management ◽  
Essential Element ◽  
Specific Situation ◽  
The South ◽  
The North ◽  
Time Space ◽  
Starting Point ◽  
The Impact

Are there any common patterns in the transition processes from traditional and more or less sustainable forest management to exploitative use, which can regularly be observed both in central Europe and in the countries of the South (e.g. India or Indonesia)? Attempts were made with a time-space-model to typify those force fields, in which traditional sustainable forest management is undermined and is then transformed into a modern type of sustainable forest management. Although it is unlikely that the history of the North will become the future of the South, the glimpse into the northern past offers a useful starting point for the understanding of the current situation in the South, which in turn could stimulate the debate on development. For instance, the patterns which stand behind the conflicts on forest use in the Himalayas are very similar to the conflicts in the Alps. In the same way, the impact of socio-economic changes on the environment – key word ‹globalisation› – is often much the same. To recognize comparable patterns can be very valuable because it can act as a stimulant for the search of political, legal and technical solutions adapted to a specific situation. For the global community the realization of the way political-economic alliances work at the head of the ‹globalisationwave›can only signify to carry on trying to find a common language and understanding at the negotiation tables. On the lee side of the destructive breaker it is necessary to conserve and care for what survived. As it was the case in Switzerland these forest islands could once become the germination points for the genesis of a cultural landscape, where close-to-nature managed forests will constitute an essential element.

Healthcare System in the Arctic Zone of Russia. Known and Emerging Issues and Solutions to Them

2019 ◽  
pp. 3-20
Author(s):  
V.N. Leksin
Keyword(s):  
Metallurgical Industry ◽  
Healthcare Services ◽  
The Arctic ◽  
Russian Arctic ◽  
Arctic Zone ◽  
Shift Workers ◽  
The North ◽  
Medical Institutions ◽  
Emerging Issues ◽  
The Impact

The impact on healthcare organization on the territory of Russian Arctic of unique natural and climatic, demographic, ethnic, settlement and professional factors of influencing the health of population, constantly or temporarily living on this territory is studied. The necessity is substantiated of various forms and resource provision with healthcare services such real and potential patients of Arctic medical institutions, as representatives of indigenous small peoples of the North, workers of mining and metallurgical industry, military personnel, sailors and shift workers. In this connection a correction of a number of All-Russian normative acts is proposed.

A general practice provider federation in a mixed health economy in England: a case study investigation

2018 ◽  
Vol 68 (suppl 1) ◽  
pp. bjgp18X696929
Author(s):  
Jill Mitchell
Keyword(s):  
General Practice ◽  
Shared Vision ◽  
Health Economy ◽  
Structured Interviews ◽  
The North ◽  
Common Strategy ◽  
Common Purpose ◽  
Collaborative Working ◽  
The Impact

BackgroundThere is an emerging debate that general practice in its current format is out-dated and there is a requirement to move to a federated model of provision where groups of Practices come together. The emergence of federations has developed over the past 5 years but the factors that influence how federations develop and the impact of this new model is an under researched area.AimThe study explored the rationale around why a group of independent GP practices opted to pursue an alternative business venture and the benefits that this strategy offered.MethodA single organisational case study of a federation in the North of England was conducted between 2011–2016. Mixed methods data collection included individual and group semi-structured interviews and quantitative surveys.ResultsFederations promote collaborative working, relying on strategic coherence of multiple individual GP practices through a shared vision and common purpose. Findings revealed many complexities in implementing a common strategy across multiple independent businesses. The ability of the federation to gain legitimacy was two dimensional – externally and internally. The venture had mixed successes, but their approach to quality improvement proved innovative and demonstrated outcomes on a population basis. The study identified significant pressures that practices were experiencing and the need to seek alternative ways of working but there was no shared vision or inclination to relinquish individual practice autonomy.ConclusionOrganisational development support is critical to reform General Practice. Whether central funding through the GP Five Year Forward View will achieve the scale of change required is yet to be evidenced.

The Impact of Sanctions on North Korea’s Foreign Trade from the Perspective of the Comparative Advantage Theory

2019 ◽  
pp. 4-15
Author(s):  
I. A. Korgun ◽  
G. D. Toloraya
Keyword(s):  
Foreign Trade ◽  
Competitive Advantage ◽  
National Economy ◽  
North Korea ◽  
Rent Seeking ◽  
Economic Transformation ◽  
Global Trade ◽  
Negative Consequences ◽  
The North ◽  
The Impact

The presented study analyzes the opportunities for North Korea to capitalize on its competitive advantages in foreign trade in the context of sanctions.Aim. The study aims to identify mechanisms that allow North Korea to engage in foreign trade in circumvention of UN sanctions and to analyze their impact on the national economy.Tasks. The authors analyze the structure of North Korea’s national economy, its initial competitive advantage, identify the specific features of North Korea’s foreign trade in the context of sanctions, and determine the consequences of illicit trade in circumvention of sanctions for the national economy.Methods. This study uses an interdisciplinary approach that combines the classical theory of competitive advantage with the concept of rent seeking, with the concept of rent seeking and analysis of trade flows.Results. The study shows that, despite the restrictions imposed by sanctions, North Korea strives to make the most of its advantages, such as resource availability and cheap labor, in global trade. The country builds its own export-import chains in circumvention of sanctions. These chains are rather mobile, flexible, and controlled by the elite. As a result, benefits from trade that could be evenly distributed among the population are concentrated in the hands of a narrow segment of society. ‘Rent seeking’ makes it possible to formulate the negative consequences of these processes for the North Korean economy and the international community.Conclusions. Solving the North Korean issue requires an economic transformation in the country through the replacement of restrictive sanctions with more constructive ones. The exclusion of North Korea from open global trade leads to the country’s marginalization and impairs the transparency of international commodity flows.

Environmental impact of nutrients from nordic fish farming

1995 ◽  
Vol 31 (10) ◽  
pp. 61-71 ◽  
Author(s):  
M. Enell
Keyword(s):  
Major Part ◽  
Fish Farming ◽  
Fish Farms ◽  
Feed Composition ◽  
The North ◽  
Comprehensive Development ◽  
The Baltic ◽  
Inland Water Bodies ◽  
The Impact ◽  
Feed Coefficient

During the last 20 years there has been an interesting development of the Nordic fish farming, with regard to the feeding and farming technology and to the increase in production quantities. During the period 1974-1994 the production increased from 15,800 to about 250,000 tonnes/year. In 1974 the major part of the production was in Denmark, and in 1994 the major part was in Norway. The nutrient impact of fish farming on surrounding sea areas is mainly a function of the feed coefficient, the feed composition and metabolic processes in the fish. The comprehensive development of the feed composition and the feeding technology has resulted in reduced load of unmetabolized nutrients from fish farms, calculated per tonne fish produced. In 1974 the mean Nordic feed coefficient was 2.08 and in 1994 the coefficient was 1.25. Feed coefficients of 1.0-1.1 are now reported for Danish and Norwegian freshwater and marine fish farms. The nitrogen (N) and phosphorus (P) content of the feed has decreased, in addition the quality of the nutrient substances in the feed has changed, especially for N. The N content has decreased from 7.8 to 6.8% during the period 1974-1994 and the content of P has decreased from 1.7 to 0.7% during the same period. This development of the feed coefficient and the feed composition has resulted in a present load from a typical Nordic fish farm of 55 kg N and 4.8 kg P/t fish produced. The figures for 1974 were 132 kg N and 31 kg P/t fish produced. The Nordic fish farming production in 1994 resulted in a load of about 13,750 t N and about 1,200 t P on the actual recipients. The load from the Swedish, Finnish and Danish fish farming operations, with the Baltic Sea and the Skagerrak as the recipients, is negligible in comparison with other pollution sources. The quantities of N and P from the fish farming are equal to 0.5% of the atmospheric deposition on the sea surface and 3% of the atmospheric P load. Norwegian, Icelandic and the Faroe Islands fish farming operations are using the North Sea and the Norwegian Sea as the recipients. However, the nutrient load from single fish farms in certain coastal and inland water bodies can be significant and must be considered in the impact assessment together with other sources.

Preaching and Sermons

2017 ◽  
Author(s):  
Robert H. Ellison
Keyword(s):  
Eighteenth Century ◽  
North Atlantic ◽  
Religious Revival ◽  
Early Nineteenth Century ◽  
Denominational Identity ◽  
The North ◽  
The North Atlantic ◽  
The One ◽  
The Impact

Prompted by the convulsions of the late eighteenth century and inspired by the expansion of evangelicalism across the North Atlantic world, Protestant Dissenters from the 1790s eagerly subscribed to a millennial vision of a world transformed through missionary activism and religious revival. Voluntary societies proliferated in the early nineteenth century to spread the gospel and transform society at home and overseas. In doing so, they engaged many thousands of converts who felt the call to share their experience of personal conversion with others. Though social respectability and business methods became a notable feature of Victorian Nonconformity, the religious populism of the earlier period did not disappear and religious revival remained a key component of Dissenting experience. The impact of this revitalization was mixed. On the one hand, growth was not sustained in the long term and, to some extent, involvement in interdenominational activity undermined denominational identity; on the other hand, Nonconformists gained a social and political prominence they had not enjoyed since the middle of the seventeenth century and their efforts laid the basis for the twentieth-century explosion of evangelicalism in Africa, Asia, and South America.

Sign in / Sign up

Export Citation Format

Share Document