scholarly journals Dynamics of Live Oil Droplets and Natural Gas Bubbles in Deep Water

2020 ◽  
Vol 54 (19) ◽  
pp. 11865-11875
Author(s):  
Jonas Gros ◽  
J. Samuel Arey ◽  
Scott A. Socolofsky ◽  
Anusha L. Dissanayake
Keyword(s):  
Natural Gas ◽  
Deep Water ◽  
Gas Bubbles ◽  
Oil Droplets ◽  
Live Oil

Ultrasonic Scattering Measurements of Dispersed Oil Droplets in the Presence of Gas

2014 ◽  
Vol 2014 (1) ◽  
pp. 266-282 ◽  
Author(s):  
Paul D. Panetta ◽  
Dale McElhone ◽  
Kyle Winfield ◽  
Grace Cartwright
Keyword(s):  
Natural Gas ◽  
Water Column ◽  
Droplet Size ◽  
Oil Spills ◽  
Acoustic Scattering ◽  
Gas Bubbles ◽  
Deepwater Horizon ◽  
Oil Droplets ◽  
Large Wave ◽  
Dispersed Oil

ABSTRACT To help minimize the effects of oil spills on marine environments, chemical dispersants are used to disperse the oil in the water column so the oil can be consumed by naturally occurring bacteria. During the Deepwater Horizon incident, 1.1 million gallons of dispersant were injected directly into the flowing plume of oil and natural gas over 1500 meters deep. Dispersant's main effect is to decrease the surface tension at the oil-water interface causing the oil to form droplets smaller than ~70 microns so they can remain in the water column. Currently the efficacy of aerial applied dispersants on surface slicks is determined by measuring the droplet size decrease using a Laser In-Situ Scattering Transmissometer (LISST) or by detecting the oil in the water column using fluorometers. LISST instruments are limited to dilute mixtures, below ~500 ppm, because the LISST signal saturates for concentrated mixtures, and their windows can become occluded by oil and biofilms. Fluorometers only measure oil concentration; thus they cannot distinguish between naturally dispersed oil droplets, which can float back to the surface, from chemically dispersed oil droplets, which will remain in the water column to be naturally biodegraded. When gas is present as was the case in the Deepwater Horizon incident where it was estimated that the plume consisted of ~22% natural gas, the LISST cannot distinguish between oil droplets and gas bubbles and thus is not able to track the effectiveness of dispersants in the presence of gas. Acoustic measurements overcome the problems associated with the LISST and fluorometers and are ideal for applications subsurface near a blowout and for low ppm levels expected for surface slicks. One of the key features of the sound wave propagating through the water is the scattering at the interface between the water and object. In previous work we showed the proof of concept to measure the average oil droplet size using acoustic. We used the resonance behavior of the gas bubbles to identify them and separate their contribution to the measured acoustic scattering for various oil and dispersant combinations . We developed acoustic scattering and resonance measurements to track the size of oil droplets in the presence of gas during subsurface releases at SINTEF and in Ohmsett's large wave tank.

scholarly journals Rheology of THF hydrate slurries at high pressure

2020 ◽  
Vol 75 ◽  
pp. 16
Author(s):  
Paulo H. de Lima Silva ◽  
Mônica F. Naccache ◽  
Paulo R. de Souza Mendes ◽  
Adriana Teixeira ◽  
Leandro S. Valim
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Natural Gas ◽  
Deep Water ◽  
Flow Behavior ◽  
Oil Industry ◽  
Production Lines ◽  
Oil Emulsions ◽  
Slurry Viscosity ◽  
Financial Losses

One of the main issues in the area of drilling and production in deep and ultra-deep water in the oil industry is the formation of natural gas hydrates. Hydrates are crystalline structures resembling ice, which are usually formed in conditions of high pressure and low temperature. Once these structures are formed, they can grow and agglomerate, forming plugs that can eventually completely or partially block the production lines, causing huge financial losses. To predict flow behavior of these fluids inside the production lines, it is necessary to understand their mechanical behavior. This work analyzes the rheological behavior of hydrates slurries formed by a mixture of water and Tetrahydrofuran (THF) under high pressure and low temperature conditions, close to the ones found in deep water oil exploration. The THF hydrates form similar structures as the hydrates originally formed in the water-in-oil emulsions in the presence of natural gas, at extreme conditions of high pressure and low temperature. The experiments revealed some important issues that need to be taken into account in the rheological measurements. The results obtained show that the hydrate slurry viscosity increases with pressure. Oscillatory tests showed that elasticity and yield stress also increase with pressure.

Numerical Study on Evaporation of Lubricating Oil Droplets Under Natural Gas Engine Conditions

2018 ◽  
Author(s):  
Liyan Feng ◽  
Zixin Wang ◽  
Ping Yi ◽  
Weixin Gong ◽  
Jingchen Cui ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Natural Gas ◽  
Methane Concentration ◽  
Evaporation Rate ◽  
Carbon Number ◽  
Droplet Evaporation ◽  
Lubricating Oil ◽  
Oil Droplets ◽  
Oil Droplet ◽  
Natural Gas Engines

The distribution of lubricating oil droplets in cylinder is one of main causes of abnormal combustion of natural gas engines. The evaporation of lubricating oil droplet is one of the key sub-processes controlling its auto-ignition event. The components of lubricating oil with different carbon number (16–50) shows significantly different evaporation and ignition characteristics from gasoline and diesel fuels. Even though there are many evaporation models focusing on the evaporation behaviors of multi-component droplets, most of them are limited to the liquid fuels, which are composed by more volatile hydrocarbons. Therefore, understanding the evaporation characteristics of lubricating oil droplets is very important for investigating the mechanism of abnormal combustion of natural gas engines. In this study, a multi-component evaporation model for lubricating oil was developed, which considers several key characteristics in the droplet evaporation process, including the finite heat conduction and limited mass diffusion in liquid phase, multi-component diffusion in gas phase, real vapor-liquid equilibrium at the droplet interface, as well as the nitrogen quantity dissolved in liquid phase. The simulation results by this model were compared with experimental results, and good agreements have been achieved. Then, this model was used to study the evaporation behaviors of different hydrocarbon droplets, including lubricating oil droplet. The influences of ambient temperatures and pressures, as well as methane concentration on evaporation characteristics (namely the heat up period, average evaporation rate, and droplet lifetime) were investigated. The results show that both heat up period and evaporation rate of lubricating oil droplets increase as the methane concentration increases. Besides, the droplet lifetime monotonically decreases as the ambient pressure decreases. This is different from the diesel and gasoline droplets, for which the effects of pressure on the droplet evaporation behaviors are depended on the ambient temperature.

Measurements of hydrate film fracture under conditions simulating the rise of hydrated gas bubbles in deep water

2014 ◽  
Vol 116 ◽  
pp. 109-117 ◽  
Author(s):  
Sheng-Li Li ◽  
Chang-Yu Sun ◽  
Guang-Jin Chen ◽  
Zhi-Yun Li ◽  
Qing-Lan Ma ◽  
...  
Keyword(s):  
Deep Water ◽  
Gas Bubbles ◽  
Hydrate Film

Identification of Natural Gas Hydrates in Blocks 25a, 25b, 26 and 27 Offshore Trinidad Using Available Well Log Data

2014 ◽  
Author(s):  
M. M. Smith ◽  
L. E. Sobers
Keyword(s):  
Natural Gas ◽  
Deep Water ◽  
Gas Hydrates ◽  
Seismic Data ◽  
East Coast ◽  
Depositional Environments ◽  
Well Log ◽  
Borehole Data ◽  
Log Data ◽  
Natural Gas Hydrates

Abstract Natural gas hydrates can be found in conventional hydrocarbon depositional environments such as clastic marine sediments, siltstones and unconsolidated sands and in oceanic environments for reservoir pressures greater than 663 psi (46 bars) and temperatures less than 20 °C. These conditions are found in the deep water (> 300 m) acreage off the South East coast of Trinidad. Natural gas hydrates have been recovered in this area during drilling and seismic data have shown that there may be deposits in some areas. In this study we reviewed all the available borehole data and employed well log interpretation techniques to identify natural gas hydrates in the deep water acreage blocks 25 a, 25 b, 26 and 27 off the Trinidad South East coast. The analysis of well log data for the given depths did not present evidence to suggest the presence of natural gas hydrates in Blocks 25 a, 25 b, 26 and 27. In this paper we present our analysis of the data available and recommend the formation depths which should be logged in during the deep water exploration drilling to confirm the seismic data and core data which indicate the presence of natural gas hydrates in these blocks.

Options for Monetising Deep Water Gas in Trinidad and Tobago

2014 ◽  
Author(s):  
N. A. Alleyne ◽  
V.. Stoute
Keyword(s):  
Natural Gas ◽  
Trinidad And Tobago ◽  
Deep Water ◽  
Fossil Fuels ◽  
Critical Path ◽  
Petroleum Exploration ◽  
Financial Outcomes ◽  
Associated Gas ◽  
Gas To Liquids ◽  
Water Gas

Abstract Notwithstanding the global thrust to develop renewable sources of energy, fossil fuels, coal, crude oil and natural gas are expected to play a significant role in meeting the world's energy needs for decades to come. Natural gas with the highest hydrogen concentration among the fossil fuels is the preferred fossil fuel from an environmental impact standpoint. Trinidad and Tobago, like the rest of the world, is taking its petroleum exploration activities into deep water, its onshore and continental shelf provinces being fully explored. The development of petroleum reservoirs in deep water has many challenges. This paper explores the unique challenges posed by developing deep water gas fields with a focus on the options available for monetising the natural gas produced from these fields. The options for getting gas to market are well known and include pipelines, liquefied natural gas (LNG), compressed natural gas (CNG), gas to solid petrochemicals (GTS), gas to liquids (GTL) and gas to wire (GTW). Most of these options are operating in Trinidad and Tobago. The paper evaluates the financial outcomes from applying the pipeline, LNG and CNG options, either offshore or onshore, for gas extracted from deep water fields across a range of reserve levels and well productivities. It aims to establish criteria for deciding which means of monetisation is preferred. The reserve and productivity ranges reflect typical values encountered in the deep water provinces in Latin America, North America and Africa. These provinces account for 85% of all the deep water fields and 74 % the deep water reserves which have been discovered worldwide. Because the paper focuses on the monetisation of natural gas, its findings will be applicable to any successful deep water exploration in Trinidad and Tobago because all situations, even the discovery of oil, will require that the associated gas be handled. The handling of gas has the potential of being on the critical path in deciding on the development of deep water fields in Trinidad and Tobago.

Natural gas generation in the deep-water area of the Qiongdongnan Basin, China

2018 ◽  
Vol 36 (24) ◽  
pp. 2125-2131
Author(s):  
Long Su ◽  
Dongwei Zhang ◽  
Peng Liu ◽  
Ying Chen ◽  
Jihui Lin
Keyword(s):  
Natural Gas ◽  
Deep Water ◽  
Water Area ◽  
Qiongdongnan Basin ◽  
Gas Generation ◽  
Deep Water Area

scholarly journals Deflection of natural oil droplets through the water column in deep-water environments: The case of the Lower Congo Basin

2018 ◽  
Vol 136 ◽  
pp. 44-61 ◽  
Author(s):  
Romain Jatiault ◽  
Damien Dhont ◽  
Lies Loncke ◽  
Xavier Durrieu de Madron ◽  
Dominique Dubucq ◽  
...  
Keyword(s):  
Water Column ◽  
Deep Water ◽  
Congo Basin ◽  
Oil Droplets ◽  
Natural Oil
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