Experimental Study on Natural-Gas-Hydrate-Slurry Flow

Abstract

Summary To better understand hydrate-slurry flow, a series of experiments was performed, including water, natural gas, and diesel oil, under 4-MPa system pressure and 1.25-m/s initial linear velocity. The experiments have been conducted in a high-pressure hydrate-flow loop newly constructed at China University of Petroleum (Beijing), and dedicated to flow-assurance studies. A focused-beam reflectance measurement (FBRM) probe is installed in this flow loop, which provides a qualitative chord length distribution (CLD) of the particles/droplets in the system. First, the influence of flow rate on the hydrate-slurry flow was discussed. Then, we studied other influencing factors—such as water cut and additive dosage—on the hydrate induction period and the CLD before/after hydrate formation. Third, a new correlation was fitted between the dimensionless rheological index n′ and water cut as well as additive dosage, according to these experimental data. Finally, a laminar-flow model for the prediction of the pressure drop for the quasisingle-phase hydrate slurry was established, and tested by comparison with the experimental results in this paper.

Study on the growth rate of natural gas hydrate in water-in-oil emulsion system using a high-pressure flow loop

“…23 What has been done was to try to simulate these conditions in a laboratory loop and study the hydrate formation. [24][25][26][27][28][29][30][31][32][33][34][35][36] Turner et al 23 and Lv et al 26 proposed a hydrate formation mechanism, expressed as hydrates forming and growing as shells outside the water droplets entrained in the oil phase, as water-in-oil emulsion. Shi et al 29,30 developed an inward and outward hydrate growth shell model to describe hydrate formation in a water-in-oil emulsion system, which considered the inuences of kinetics as well as mass and heat transfer on hydrate formation.…”

Study on the decomposition mechanism and kinetic model of natural gas hydrate slurry in water-in-oil emulsion flowing systems

“… 2,5,6 Research on the hydrate dissociation mechanisms is the key to managing the issues of hydrate blockage in flow systems, 7 exploring deep-water hydrate resources, 8–11 applying hydrate technology as gas media for gas storage and transportation, 12 purification and separation, 13–16 and developing hydrate slurry transportation technology. 17–21 …”

Study on the Decomposition Mechanism of Natural Gas Hydrate Particles and Its Microscopic Agglomeration Characteristics

“…As exploration and production is going into deeper water, the focus of flow-assurance strategies are shifting from traditional methods to risk-control techniques [2]. Hydrate slurry flow has gradually gained the attention of researchers [13][14][15][16][17][18][19][20], who have referred to it as a form of hydrate risk control. However, studies on hydrate slurry are still in the period of experimental investigation with preliminary theoretical development [21].…”