Latest Developments In Floating LNG Liquefaction Technologies: How We Are Combining Proven and Innovative Technologies For The Future

Among Floating liquefied natural gas (FLNG) operations, natural gas liquefaction is the most energy intensive. Hence, to achieve energy-efficient and eco-friendly FLNG operations that can meet offshore environment requirements, a hydrofluoroolefin-based single mixed refrigerant (SMR) natural gas (NG) liquefaction process is proposed. The proposed process is optimized using a sine cosine paradigm to reduce the overall energy consumption. Then, the economic performance of the proposed process is performed and analyzed against that of the conventional LNG process. Finally, uncertainty quantification is performed to analyze the process outputs under the effects of uncertain key decision variables to guarantee operational reliability. The optimization yields an energy consumption of 0.2317 kW, resulting in a 41.73% energy saving compared to the conventional SMR process. Moreover, the total annualized cost is reduced to 26.02% owing to the appropriate mixed refrigerant selection and process design. The results of the uncertainty quantification analysis indicate that the flow rates of methane and butane, the evaporation pressure, and the condensation pressure are the most influential factors when processing energy consumption and utilizing the minimum internal temperature approach. This study highlights the importance of introducing eco-friendly refrigerants to replace conventional refrigerants used in NG liquefaction processes.

This chapter provides a brief review of the developments in the optimization of Natural gas (NG) liquefaction techniques since 2001. NG liquefaction is energy intensive and small improvements in liquefaction efficiency brings huge cost benefits thus optimization is needed. To tackle the NG liquefaction optimization problem, two different optimization philosophies, i) deterministic and ii) stochastic, have been adopted. The limitations of the deterministic approach have paved the way for derivative-free stochastic approaches. Although both techniques work well for the reported problem, their application is limited to the specific problems and generalization is quite difficult. Therefore to overcome this problem, a third of the so called knowledge-inspired class have been evolved for NG liquefaction optimization. Thus, this chapter covers the major development that took place in NG liquefaction area and after reviewing the trends future research directions are given.

This chapter provides a brief review of the developments in the optimization of Natural gas (NG) liquefaction techniques since 2001. NG liquefaction is energy intensive and small improvements in liquefaction efficiency brings huge cost benefits thus optimization is needed. To tackle the NG liquefaction optimization problem, two different optimization philosophies, i) deterministic and ii) stochastic, have been adopted. The limitations of the deterministic approach have paved the way for derivative-free stochastic approaches. Although both techniques work well for the reported problem, their application is limited to the specific problems and generalization is quite difficult. Therefore to overcome this problem, a third of the so called knowledge-inspired class have been evolved for NG liquefaction optimization. Thus, this chapter covers the major development that took place in NG liquefaction area and after reviewing the trends future research directions are given.

Brief Synopses of New Arabic-Language Publications

Feasibility study of carbon dioxide capture from power plants and other major stationary sources and storage in Iranian oil fields for enhanced oil recovery (EOR)

Exploration activities in Campos Basin offshore Brazil started in 1968 with seismic surveys carried out by PETROBRAS. The first oil discovery was made in 1974, one hundred kilometers offshore in 126 meters water depth. Thirthy oil and gas fields have been discovered so far. The main producing reservoirs are sandstones but production is also obtained from limestones, Early Cretaceous to Miocene in age. Campos Basin production started in August, 1977, through a floating production system with one single well producing 12,000 BOPD. As of December, 1987, the average daily output of the basin was 367,000 BOPD. Campos Basin proved reserves at the end of 1987, using 500 m (1,640 ft) as water depth cut off, reached 1.6 billion barrels of oil and 39.5 billion cubic meters of natural gas (1.4 Tcf). Deep water discoveries as from 1984 are expected to increase the total reserves to 7.0 billion barrels of oil and over 100 billion cubic meters of natural gas (3.5 Tcf). Floating Production Systems with subsea completions are being widely used as the main technique for petroleum recovery from small and medium size fields in Campos Basin. Nineteen of those systems were installed, redeployed or discontinued, arriving to the current configuration of 12 systems and more than 100 subsea completions, five of which in waters deeper than 380 meters. Future plans comprise the development by steps of the giant Albacora and Marlim fields, with recoverable oil reserves of at least 1.1 and 3.6 billion barrels, respectively, using floating production systems and subsea completions between 250 to 800 meters water depth. INTRODUCTION Located off the coastline of Rio de Janeiro State, (Fig. 1), Campos Basin is the Brazilian principal source of petroleum accounting for 60% of the domestic crude oil output of 610,000 barrels per day. Most of the Campos fields now producing are located in water depths shallower than 200 meters (656 ft). The proved reserves of the basin, at the end of 1987, were 1.6 billion barrels of crude oil and 39.5 billion cubic meters of natural gas(1.4 Tcf). The basin scenario has been changing as from November, 1984 when the first deep water field, the giant Albacora, with over one billion barrels of recoverable oil, was discovered. In February, 1985, a second deep water giant, the Marlim Field, confirmed the huge hydrocarbon potential of the basin adding more than 3.5 billion barrels to the recoverable oil estimates. Marlim Field is still under delimitation, particularly its southern extension. The major challenge facing PETROBRÁS, is developing technology required to produce oil from those deep water giant fields as part of the all-out effort to diminish the present dependence of Brazil to foreign sources of petroleum supply.

Liquefied natural gas supply chain using liquid air as a cold carrier: Novel method for energy recovery

Optimization of mixed fluid cascade LNG process using a multivariate Coggins step-up approach: Overall compression power reduction and exergy loss analysis

Mixed refrigerant (MR) system is commonly used for natural gas liquefaction plants due to its higher efficiency of heat transfer rate. Dual mixed refrigerant process (DMR) applies mixed refrigerant in the precooling unit to overcome the inherent limitations of propane refrigerant precooling; thus, it is further adaptable to liquefy the raw gas with wider external conditions. In the paper, taking the clean gas from one oilfield in Xinjiang, China, as the research object, the relevant parameters of key nodes in the DMR natural gas liquefaction process were obtained according to the simulation of the natural gas liquefaction process by HYSYS. Based on these parameters of the key nodes and the exergy analysis, the exergy loss of every facility in the process was calculated. It is found that the liquefaction ratio of natural gas is 90%, and the total exergy loss of compressors is 68521.70 kW. The exergy loss of compressors is the most, the proportion of which can reach 99.43% in the whole liquefaction process. It is very significant for the exergy analysis to get the energy efficiency of every facility and then provide some measures to decrease the exergy loss in the process.

Advanced natural gas liquefaction and regasification processes: Liquefied natural gas supply chain with cryogenic carbon capture and storage

On the sustainability of small-scale expansion-based natural gas liquefaction: Supersonic separator, Joule-Thomson, and turbo-expander

With the requirement of energy decarbonization, natural gas (NG) and hydrogen (H2) become increasingly important in the world’s energy landscape. The liquefaction of NG and H2 significantly increases energy density, facilitating large-scale storage and long-distance transport. However, conventional liquefaction processes mainly adopt electricity-driven compression refrigeration technology, which generally results in high energy consumption and carbon dioxide emissions. Absorption refrigeration technology (ART) presents a promising avenue for enhancing energy efficiency and reducing emissions in both NG and H2 liquefaction processes. Its ability to utilize industrial waste heat and renewable thermal energy sources over a large temperature range makes it particularly attractive for sustainable energy practices. This review comprehensively analyzes the progress of ART in terms of working pairs, cycle configurations, and heat and mass transfer in main components. To operate under different driven heat sources and refrigeration temperatures, working pairs exhibit a diversified development trend. The environment-friendly and high-efficiency working pairs, in which ionic liquids and deep eutectic solvents are new absorbents, exhibit promising development potential. Through the coupling of heat and mass transfer within the cycle or the addition of sub-components, cycle configurations with higher energy efficiency and a wider range of operational conditions are greatly focused. Additives, ultrasonic oscillations, and mechanical treatment of heat exchanger surfaces efficiently enhance heat and mass transfer in the absorbers and generators of ART. Notably, nanoparticle additives and ultrasonic oscillations demonstrate a synergistic enhancement effect, which could significantly improve the energy efficiency of ART. For the conventional NG and H2 liquefaction processes, the energy-saving and carbon emission reduction potential of ART is analyzed from the perspectives of specific power consumption (SPC) and carbon dioxide emissions (CEs). The results show that ART integrated into the liquefaction processes could reduce the SPC and CE by 10~38% and 10~36% for NG liquefaction processes, and 2~24% and 5~24% for H2 liquefaction processes. ART, which can achieve lower precooling temperatures and higher energy efficiency, shows more attractive perspectives in low carbon emissions of NG and H2 liquefaction.

Conceptual design and modeling of novel-integrated process configurations for helium extraction and natural gas liquefaction is investigated. Mixed fluid cascade (MFC) refrigeration system is considered for providing the needed refrigeration in the natural liquefaction section. Using an absorption refrigeration system as the precooling cycle is investigated in one of the introduced processes. Integrated flash and distillation method is used for helium extraction. Purity of the extracted crude helium is 50% (mole). Process streams operational condition and specifications of the devices are presented and explained. Composite curves of the heat exchangers demonstrate that thermal design has been done properly. Ratio of the power consumption to the produced liquefied natural gas (LNG) of the MFC process is 0.265 kWh per kg LNG and applying absorption refrigeration system instead of the pre-cooling cycle decreases it to 0.1849 kWh per kg LNG. For the modified process with absorption refrigeration system helium extraction rate and power consumption ratio are 0.951 and 132.9 (kWh/[kgmole Helium]) respectively. Exergy method is applied on the under consideration processes. The results show that the compressors have the highest rate of exergy destruction among the other process equipment. An extensive economic analysis is done on the proposed processes. The results show that prime cost of the product (US$/kg LNG) for MFC and modified MFC processes are 0.1939 and 0.2069, respectively. Finally, a sensitivity analysis is done based on the economic factors such as electrical energy price and prime cost of the product.

Summary Liquefied natural gas (LNG) has yet to be deployed in the development of offshore fields in spite of several detailed studies completed and offshore technology development demonstrating its technical feasibility. The perceived risks associated with deploying unproven technology in a high construction cost and volatrile gas price environment have so far inhibited offshore liquefaction projects. The potential deployment of such technologies is of paramount importance considering the massive volumes of natural gas currently deemed as "stranded" and the exploitation of which is compelling not only because of the inherent economic benefit but also because of the otherwise adverse impact on oil production. It is conceivable that deep water offshore locations may contain quantities of natural gas rivalling those of onshore locations. Such a statement cannot even be confirmed because drilling for offshore natural gas reservoirs, expected to be found considerably deeper than oil reservoirs, has been unattractive exactly because of the absence of coherent exploitation strategies. If anything, the mere presence of large natural gas deposits even in the form of solution gas in oil is now often considered as largely undesirable because of the cost of just handling non-monetized natural gas. This paper discusses potential offshore LNG processes and reviews natural gas liquefaction cycles in the context of compactness, ease of operation, process safety, and efficiency. Particular attention is paid to the lower-efficiency turboexpander processes for plant capacities up to 3 million tonnes per annum (MTPA, approximately 0.43 Bcf/d). These cycles offer several advantages over the alternative optimized cascade and mixed refrigerant (MR) liquefiers for offshore applications.

The Kuqa foreland thrust belt, which has superior petroleum geological conditions and lines of structural belts, is an important target for natural gas exploration in Tarim basin. But owing to the bad surface conditions, the complex deformation of the underground structures and the poor quality of seismic data here, it is difficult to define the trap and evaluate the reservoir. Since the discovery of the Kela 2 gas field and the Dina 2 gas field, there was no further progress at one time. Recently, a serie of technique research aimed at the targeting Cretaceous subsalt rocks strata in Kuqa foreland thrust belt has been carried out: The application of wide line and large geophone array seismic acquisition technique in complex mountainous areas can effectively improve the quality of seismic data; With 3D anisotropy seismic pre-stack migration technique, the seismic imaging and migration homing problem of the complex over-thrust and the irregular object is effectively resolved; The modeling technology of the compressive salt-related structures effectively guides the high and steep complicated structure interpretation; The technique of recognizing and forecasting of the thick conglomerate layer in shallow strata can be applied to build the seismic velocity field and confirm the traps. The great progress in exploration technology has enriched the geological understanding and brought about three major changes in exploration: In Kelasu structure zone, the exploration target turns to deep strata from the shallow ones; In eastern Kuqa depression, it goes to tight sand gas exploration while in the western part it switches to the lithologic hydrocarbon reservoir exploration. In this way, the subsalt layer hydrocarbon exploration has made a great breakthrough, companied with a new gas exploration upsurge. In five years, Dabei-3, Keshen-2, Keshen-5, Bozi-1, Keshen-8 and many other gas reservoirs have been found. 800 billion cubic meters of natural gas has been confirmed and about 30 important traps have been reserved. The total natural gas reserves amount has exceeded 2 trillion.