Experimental Study on Hydrate Induction Time of Gas-Saturated Water-in-Oil Emulsion using a High-Pressure Flow Loop

Abstract

and available online here Cet article fait partie du dossier thématique ci-dessous publié dans la revue OGST, Vol. 70, n°6, pp. 909-1132 et téléchargeable ici D o s s i e rOil & Gas Science and Technology -Rev. IFP Energies nouvelles, Vol. 70 (2015), No. 6, pp. 909-1132 Copyright © 2015, IFP Energies nouvelles > Editorial -Enhanced Oil Recovery (EOR), Asphaltenes and HydratesÉditorial -EOR «récupération assistée du pétrole», Asphaltènes et Hydrates D. Langevin and F. Baudin ENHANCED OIL RECOVERY (EOR) > HP-HT Drilling Mud Based on Environmently-Friendly Fluorinated ChemicalsBoues de forage HP/HT à base de composés fluorés respectueux de l'environnement Abstract -Hydrate is one of the critical precipitates which have to be controlled for subsea flow assurance. The induction time of hydrate is therefore a significant parameter. However, there have been few studies on the induction time of the natural gas hydrate formation in a flow loop system. Consequently, a series of experiments were firstly performed, including water, natural gas and Diesel oil, on the hydrate induction time under various conditions such as the supercooling and supersaturation degree, water cut, anti-agglomerant dosage, etc. The experiments were conducted in a high-pressure hydrate flow loop newly constructed in the China University of Petroleum (Beijing), and dedicated to flow assurance studies. Then, based on previous research, this study puts forward a method for induction time, which is characterized by clear definition, convenient measurement and good generality. Furthermore, we investigated the influences of the experimental parameters and analyzed the experimental phenomena for the hydrate induction time in a flowing system.

Experimental study of growth kinetics of CO2 hydrates and multiphase flow properties of slurries in high pressure flow systems

“…The time interval between the start point and end point is dened as the induction time of the ow system (T ind ¼ T e À T s ). This is similar to the method proposed by Lv et al 32 for measuring the induction time of methane hydrates in oil-water emulsion systems. Taking experiment 9 as an example, Fig.…”

“…Different researchers have proposed different denitions of hydrate induction time based on different experimental systems. [30][31][32][33][34][35] In this work, induction time is described from the macroscopic aspect, including critical nuclei stage and visible crystal stage. In other words, the induction time is determined by a start point and an end point that is easy to observe and characterized by the large amount of hydrate formation.…”

An investigation on gas hydrate formation and slurry viscosity in the presence of wax crystals

“…And, the time elapsed until the appearance of a detectable volume of hydrate phase or, equivalently, until the consumption of a detectable number of gas moles is defined as induction time, which is the time taken for hydrate crystal nuclei to form . According to the definition of induction time proposed by Lv et al, the induction time is the time difference between two key points from the temperature data in the high‐pressure autoclave reactor. One point is when the temperature is at the hydrate formation equilibrium temperature (Figure ).…”

“…Because hydrate nucleation is a micro nonvisual process, induction time is generally used as a method to measure the hydrate nucleation process. Results indicate that induction time is affected by supercooling degree, supersaturation, flow shear rate, and various additives . The classic kinetic models combined with mass and heat transfer and shell growth models have been reported to predict hydrate growth process in emulsion systems.…”

Heat conduction and thermal convection on thermal front movement during natural gas hydrate thermal stimulation exploitation

“…Natural Gas Hydrate (NGH) is regarded as the most promising alternative energy resource because of its wide distribution, large resources and cleanliness [1][2][3][4]. There exist three basic techniques to extract gas contained within NGH sediment, which are thermal stimulation, depressurization and chemical inhibitor stimulation [5][6][7]. Thermal stimulation is believed to be the one of most effective of the three methods, and the movement of thermal front is the key factor controlling the exploitation procedure [8][9][10].…”