Effects of high oil viscosity on oil-gas upward flow behavior in deviated pipes

The crude oil in Kuidong region of Liaohe Tanhai Oilfield is characterized by high oil viscosity, high density, high content of colloid asphalt, low content of wax and low freezing point. In the shallow region, the large current, high content of silt, long-distance subsea buried pipeline and drift ice in winter have brought great challenge to offshore construction and oil-gas transportation. In this paper, the investigations of offshore construction project and platform process are shown. Based on the well production rate, gas-oil ratio, water cut, wellhead back pressure and outlet temperature, the range of daily transportation volume was acquired, as well as the maximum inlet pressure and pressure difference of the pump. The paper also selected technically and economically feasible pumps, then designed the public projects, corresponding electric power and self-control facilities. The selected skidded twin screw multiphase pump system can smoothly transport produced liquid to the terminal systems onshore without any effect on the daily output.

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An experimental investigation of the oil film distribution in an oil–gas cyclone separator

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408916658319 ◽

2016 ◽

Vol 231 (1) ◽

pp. 14-25 ◽

Cited By ~ 1

Author(s):

Lingzi Wang ◽

Jianmei Feng ◽

Shijing Xu ◽

Xiang Gao ◽

Xueyuan Peng

Keyword(s):

Flow Pattern ◽

Pressure Loss ◽

Film Flow ◽

Separation Efficiency ◽

Flow Behavior ◽

Outer Cylinder ◽

Cylinder Wall ◽

Cyclone Separator ◽

Oil Film ◽

Oil Gas

The film flow behavior in an oil–gas cyclone separator was experimentally studied to improve the separation efficiency in terms of the effect of the oil film on the cylinder wall. The oil film flow pattern was captured using a high-speed camera, and the cylinder wall was divided into seven regions to analyze according to the different oil film flow patterns. Along the cyclone cylinder height, the central part of the cylinder was the main flow area, in which droplet–wall collisions and oil film splashing were severe. Additionally, the oil film’s distribution characteristics under inlet velocities of 14.0, 16.0, and 18.0 m/s were compared, and the results showed that more splashing oil droplets were generated under higher inlet velocity. Moreover, changing the structure of the central channel and outer cylinder slightly changed the oil film’s area and flow pattern but exhibited a weak effect on the oil film thickness and re-entrainment. Then, an improved structure was proposed by adding a porous cylinder to the outer cyclone to avoid the generation of small splashing droplets from the oil film. The performance of the modified separator was measured in a real oil-injected compressor system, which demonstrated higher separation efficiency with no increase in static pressure loss. The separation efficiency increased by up to 2.7%, while the pressure loss decreased by up to 10%. Thus, the improved structure can improve the performance of oil–gas separators by changing the distribution and thickness of the oil film on the cylinder wall.

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The Effect of Compositional Gradient in Field Development

10.2118/205801-ms ◽

2021 ◽

Author(s):

Farasdaq Muchibbus Sajjad ◽

Steven Chandra ◽

Patrick Ivan ◽

Wingky Suganda ◽

Yudi Budiansah ◽

...

Keyword(s):

Oil Recovery ◽

Oil And Gas ◽

Flow Behavior ◽

Cross Flow ◽

Generalized Solution ◽

Oil Viscosity ◽

Compositional Gradient ◽

Field Development ◽

Scale Deposition ◽

Compositional Convection

Abstract The existence of fluid’s compositional gradient in a reservoir drives convective flow which brings significant impacts to the operations, e.g., in formulation of injected fluid for well stimulation and enhanced oil Recovery (EOR). However, fluid compositional gradient is not always included in modeling reservoir performance due to PVT sampling limitation and simulation constraint. This work aims to show the significance of compositional convection in oil/gas reservoir and provides our experiences in dealing with this issue in Indonesian’s fields. PHE ONWJ as one of the most prolific producers of oil and gas in Indonesia currently operates an offshore block that has been producing for almost 40 years. Operating in a relatively mature well, PHE ONWJ often encounters significant fluid property change namely oil viscosity and specific gravity that changes overtime as depletion process occur. Data from X field, operated by PHE ONWJ, shows that compositional convection impacts workover and tertiary operations, by deviating from simulation results. We present the evidence of compositional convection using mechanistic models. We firstly adopt field data for setting the initial composition stratification. The stratification is identified through DST or fluid sampling. We secondly perform similarity simulation to analyze the effect of compositional gradient towards oil production. Similarity simulation is performed in the simplified domain for providing generalized solution. This solution is then scaled for the real domain. Finally, we show our approach to encounter the problems. Based on the similarity study inspired by the case of X Field, it shows that the compositional stratification affects geochemistry and near-wellbore flow behavior. The compositional convection develops multiple fluid properties at different depth, which create cross flow among layers. It also causes scale deposition in near wellbore which reduces the permeability and alters rock-fluid interactions, such as wettability and relative permeability. The alteration of near-wellbore geochemistry creates severe flow assurance issues in the wellbore. The mixing of multiple fluids from different layers cause paraffin and scale deposition. In some fields, the mixing triggers severe corrosions which could impact on wellbore integrity. The compositional stratification forces us to develop multiple treatments for different layers in single wellbore. Since the fluid’s properties are different for each layer, the compatibility between injected fluid and reservoir fluids varies.

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Oil-Gas-Water Three-Phase Slug Flow Liquid Holdup Model in Horizontal Pipeline

Volume 1: Project Management; Design and Construction; Environmental Issues; GIS/Database Development; Innovative Projects and Emerging Issues; Operations and Maintenance; Pipelining in Northern Environments; Standards and Regulations ◽

10.1115/ipc2006-10269 ◽

2006 ◽

Author(s):

Jing Mei Zhao ◽

Jing Gong ◽

Da Yu

Keyword(s):

Slug Flow ◽

Water Film ◽

Mineral Oil ◽

Superficial Velocity ◽

Oil Viscosity ◽

Liquid Holdup ◽

Three Phase ◽

Water Based ◽

Water Cut ◽

Oil Gas

According to experiments and relational documents, slug regime, appeared in this experiment, can be divided into the following flow regimes: oil-based separated slug, oil-based dispersed slug, water-based separated and water-based dispersed slug. Experiments for oil-gas-water three-phase flow in a stainless steel pipe loop (25.7mm inner diameter, 52m long) are conducted. Compressed air, mineral oil and water are used as experiment medium. Mineral oil Viscosity is 64.5mPa.s at 20°C. Gas superficial velocity, liquid superficial velocity and water cut ranges are 0.5∼15 m/s, 0.05∼0.5 m/s and 0∼100% respectively. There are some strange observed in this experiment. At the very low gas superficial velocity less than 1m/s, the average liquid holdup of low liquid superficial velocity was larger than that of higher liquid superficial velocity especially in higher inlet water cut experiments. This is because at very low gas superficial velocity, the regime is separated slug flow which has water film below their liquid film zone, velocity difference between oil film and water film will affect the average liquid holdup greatly. With the increase of gas and liquid superficial velocity, the regime becomes dispersed slug flow which oil and water are homogeneous. It will be more obvious with the increasing of water cut for the thicker water film. A new liquid holdup model of oil-based and water-based separated slug has been developed. Based on statistical analysis, it is observed that the new model gives excellent results against the experimental data.

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A Comparison of Oil-Water Flow and Oil-Gas Flow in Capillary Model

Volume 4: Dynamics, Control and Uncertainty, Parts A and B ◽

10.1115/imece2012-87720 ◽

2012 ◽

Cited By ~ 1

Author(s):

Yihe Zhang ◽

Liming Dai

Keyword(s):

Pressure Drop ◽

Liquid Film ◽

Gas Flow ◽

Capillary Flow ◽

Flow Behavior ◽

Thin Liquid Film ◽

Flow Process ◽

Capillary Model ◽

Oil Water ◽

Oil Gas

A capillary model is employed to study the slug flow behavior in pore structure. Oil-water system and oil-gas system are investigated in the experiments. During the flow process, it is observed that the wetting phase liquid will generate a thin liquid film on the inner surface of the tube wall, and the liquid film plays an important role in capillary flow. At the meantime, the pressure drop across the tube is recorded during the experiment, result shows that the pressure drop magnitude is proportional to the oil slug length, while it is not significantly affected by the liquid injecting velocity.

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