Calculation of flow velocity in oil pipelines

It is simpler to calculate flow rate using flow velocity, which can be measured experimentally or calculated using the N-S equation. Simply put, it’s an estimation based on experience.

The title is flow rate, but the content talks about volume flow?

Anyway, normal flow rates are usually calculated based on velocity. .

1. How to calculate the natural gas flow rate in high-pressure conditions in oil pipelines? (Known pipeline specifications, daily production volume, pipeline temperature, and pressure) Answer: It is relatively simple to perform calculations for a single gas phase; the density of natural gas can be determined from pressure and temperature (tools such as HYSYS and ASPEN are commonly used, or tables can be consulted). There is a large amount of data available regarding natural gas, and it is quite accurate. With the daily production amount, the flow rate per hour (kg/hr) can be determined; the volume flow rate (m3/hr) is obtained from the density. Based on the pipeline specifications, the inner diameter of the pipeline can be found (make sure to use meters as the unit). The cross-sectional area of the pipeline can then be calculated (in m2). With the volume flow rate and the cross-sectional area, the flow velocity can be determined. (Velocity = volumetric flow rate/area). 2. How is the flow rate calculated for oil pipelines in a high-pressure gas-liquid mixed transport state? (Known pipeline specifications, daily liquid production volume, daily gas production volume, pipeline temperature, pressure) Answer: The method is the same as above; it’s just that the volumetric flow rate of two-phase flow is not as easy to calculate as that of single-phase flow. It is recommended that you use simulation software for calculations; it is a more accurate and appropriate method. If there is no simulation software, the volumetric flow rates of the liquid and gas are added together to obtain the total volumetric flow rate. Note that such calculations have large errors. The flow rates of actual liquids and gases are not the same; the difference varies greatly depending on the flow pattern. The case of 5%-20% in the gas phase is the most difficult to calculate, as plug flow often occurs, which has a significant impact on the pipeline and must be taken into account. In engineering design, this is by no means a minor issue. 3. How is the flow rate calculated under the condition of high-pressure transportation of oil, gas, and water in oil pipelines? (Known pipeline specifications, daily oil production, daily gas production, daily water production, pipeline temperature, pressure) Answer: Same as 2; in flow conditions, oil and water can be considered as a single liquid phase, but if the flow rate is very low, then there is a significant difference.