Dry tree well flow assurance challenges and solutions for offshore gas condensate field development

2014 ◽  
Vol 54 (2) ◽  
pp. 522
Author(s):  
Jeff Zhang ◽  
Ian Kopperman

Offshore field developments usually conceive that the dry tree wells (DTW) have less flow assurance challenges when compared with subsea development options. The relatively short vertical flow path for the DTW production risers causes fewer issues with respect to hydrate and wax management; however, the DTWs have particular flow assurance challenges due to dry tree well platforms design constraints. This extended abstract presents the various flow assurance challenges associated with the design and operation of DTWs for deepwater gas-condensate field developments, including: the impact of production riser annulus thermal behaviour and soil modelling uncertainties on the topsides materials selection; the coupling of low temperature propagation and cold liquid management issues topsides during cold well start-up; and, the narrow operating window to establish the forward flow for the downstream systems following cold well start-up. The absence of the capacity provided by subsea pipelines and flowlines, thus, leads to the requirement for integrated consideration of the DTWs and downstream topsides and potentially pipeline systems. The coupling for low temperature and liquid management issues, particularly for transient operations, requires rigorous flow assurance analysis. This extended abstract summarises the analytical solutions developed, applying the advanced flow assurance tools available, by considering the operating constraints, with the downstream process and export systems, to determine practical design solutions and operating philosophies.

2020 ◽  
Vol 52 (1) ◽  
pp. 424-435 ◽  
Author(s):  
Jeppe Nygaard ◽  
Michael Caulfield ◽  
Robert Gooder ◽  
Duncan Chedburn

AbstractThe Culzean Field is situated 240 km east of Aberdeen in Block 22/25a. The field was discovered in 2008 by well 22/25a-9Z targeting a tilted fault block, encountering lean-gas condensate in the fluvial Triassic Skagerrak (Joanne Sandstone Member) and the Jurassic Pentland formations. The field is high-pressure–high-temperature (HPHT) with initial conditions of 936 Bar (13 575 psi), 176°C (348°F) and charged with a lean-gas condensate. Development of the field was sanctioned in 2015 and is the latest UK HPHT field to be developed with start-up in mid-2019. The field development plan comprises production from six development wells drilled from a wellhead platform with bridge connections to a central process platform with accommodation on an additional bridge-linked utilities and living quarters platform. Gas is exported to shore via the Central Area Transmission System pipeline and produced condensate is exported via the floating storage and offloading vessel ‘Ailsa’. Production is expected to reach a plateau production rate in the order of 100 000 boepd with an overall recovery of up to 300 MMboe.


Author(s):  
R.R. Haliulin ◽  
◽  
S.N. Zakirov ◽  
A.H. Kha ◽  
N.E. Vedernikov ◽  
...  

2004 ◽  
Vol 16 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Venkataraman M. Iyer ◽  
Dasaratha V. Rama

Audited financial statements can be viewed as the product of negotiations between a company's management and its auditor. Relative power of these two parties is a major factor that determines the outcome of the negotiation. This study examines the impact of auditor tenure, importance of a client to an audit partner, nonaudit purchases, and prior audit firm experience of client personnel on client perceptions about their ability to persuade the auditor in the context of an accounting disagreement. We obtained responses to a survey from 124 CPAs in industry who are employed as CEOs, CFOs, controllers, or treasurers. Our results indicate that respondents from companies with short auditor tenures were somewhat more likely to indicate that they could persuade the auditor to accept their (client's) position in case of a disagreement. This finding is consistent with the argument that auditors are susceptible to influence in the early years as they are still in the process of recouping start-up costs, but is not consistent with concerns expressed by legislators and others that long auditor tenures will adversely affect audit quality. Respondents who believed their business was more important for the audit partner were also more likely to believe that they could persuade the auditor. However, the purchase of nonaudit services and prior audit experience were not related to client's perceptions about their ability to persuade the auditor.


2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.


2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.


Author(s):  
Junfan Yu ◽  
Saskia De Klerk ◽  
Michael Hess

AbstractThis research focuses on how entrepreneurs utilize cronyism to acquire resources. A case study method allowed us to explore three firms in the private property development industry in China. These firms uniquely cultivated cronyism and achieved distinctly different outcomes. Our findings highlight Chinese entrepreneurs in start-up ventures and later-stage enterprises employ cronyism. The underlying rationale for using cronyism have common and heterogeneous motivations. The similarity and distinguishing rationale also apply to the impact of cronyism. We also find two contingency working mechanisms for cronyism: entrepreneurial characteristics and a staged model for cronyism. With the firm’s growth, cronyism remains important, but firms with more community involvement outperform others. This research contributes to the theory on strategic network utilization for resource acquisition during entrepreneurial development stages. We investigate how entrepreneurial strategies can assist in adapting to the “rules of the game” while utilizing resources within the set contextual constraints.


2011 ◽  
Vol 332-334 ◽  
pp. 27-30 ◽  
Author(s):  
Mei Niu ◽  
Zi Lu Wu ◽  
Jin Ming Dai ◽  
Wen Sheng Hou ◽  
Sheng Shi ◽  
...  

Wool fiber was firstly pretreated by nano-SiO2/Ag antibacterial agent, and then dyed with an acid dyes at low temperature by ultrasonic dyeing. Many factors had an important influence on the dye ability and the antibacterial behavior during the dyeing process of antibacterial wool fiber. The experimental results indicate that the dye-takeup rates of antibacterial wool fiber were enhanced with the increase of the concentration of nano-SiO2/Ag, the dyeing temperature, the dyeing time and the ultrasonic frequency (less than 60Hz). However, the antibacterial ratios of wool fiber were declined in the impact of these factors other than the concentration of antibacterial agent.


2014 ◽  
Vol 20 (6) ◽  
pp. 517-541 ◽  
Author(s):  
Wadid Lamine ◽  
Sarfraz Mian ◽  
Alain Fayolle

Purpose – This paper seeks to advance ongoing research in entrepreneurial perseverance. While the concept of perseverance is not new, few researchers paid attention to behavioural persistence in the entrepreneurial context. The purpose of this paper is to explore the emergence of new technology based firms (NTBF) by focusing on the role of nascent entrepreneurs’ social skills in the meeting the changes of entrepreneurial perseverance. Design/methodology/approach – In this paper the authors study the start-up phase of entrepreneurial process. The authors opted for a longitudinal case study approach in order to enhance the knowledge on entrepreneurs’ social skills and perseverance. For triangulation purpose the data were gathered using four different information sources. The use of Nvivo8 as the data analysis tool helped to impose a discipline and structure which facilitated the extraction of core insights. Findings – This paper contributes to the understanding of the entrepreneurial perseverance in the context of new venture creation. Particularly, reading the entrepreneurial process through the lens of the perseverance strategies model (Van Gelderen, 2012) provided a way to identify and then to assess the impact of the social skills on the overall entrepreneurial perseverance and their combined impact on the performance of NTBF creation process. In doing so, the authors identify the impact of entrepreneurs’ social skills to deal with a series of entrepreneurial problems such as scarcity of resources, uncertainty and ambiguity and consequently their impact on the likelihood of survival for new ventures. The issues that arose mostly reflected the inherent complexity of technology transfer processes, the university and entrepreneurs’ diverging cultures, and the very characteristics of the start-up phase of NTBFs. The findings reveal how social skills impact the entrepreneurial paths and probable outcomes. Research limitations/implications – This paper contributes to the understanding of the entrepreneurial perseverance in the context of NTBF creation. The findings reveal how social skills and perseverance impact the entrepreneurial paths and probable outcomes. Practical implications – The paper has implications for entrepreneurial support mechanisms such as technology business incubators in helping them to improve the efficacy and efficiency of their assistance to entrepreneurs through the development of their skill-sets and perseverance and providing enabling networking. In addition, the research has implications for entrepreneurship education and training. Indeed, there is an urgent need to design and implement courses and programs aiming at developing soft skills in entrepreneurship. Originality/value – In exploring networking and issues of perseverance for nascent entrepreneurs operating in new technology-based sectors, which the authors consider as an under searched area in entrepreneurial literature.


2009 ◽  
Vol 145-146 ◽  
pp. 177-180 ◽  
Author(s):  
Roger Loo ◽  
Andriy Hikavyy ◽  
Frederik E. Leys ◽  
Masayuki Wada ◽  
Kenichi Sano ◽  
...  

Several device concepts have been further evaluated after the successful implementation of epitaxial Si, SiGe and/or Si:C layers. Most of the next device generations will put limitations on the thermal budget of the deposition processes without making concessions on the epitaxial layer quality. In this work we address the impact of ex-situ wet chemical cleans and in-situ pre-epi bake steps, which are required to obtain oxide free Si surfaces for epitaxial growth. The combination of defect measurements, Secondary Ion Mass Spectroscopy, photoluminescence, lifetime measurements, and electrical diode characterization gives a very complete overview of the performance of low-temperature pre-epi cleaning methods. Contamination at the epi/substrate interface cannot be avoided if the pre-epi bake temperature is too low. This interface contamination is traceable by the photoluminescence and lifetime measurements. It may affect device characteristics by enhanced leakage currents and eventually by yield issues due to SiGe layer relaxation or other defect generation. A comparison of state of the art 200 mm and 300 mm process equipment indicates that for the same thermal budgets the lowest contamination levels are obtained for the 300 mm equipments.


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