2 Feb, 2015

PetroSkills Introduces new e-Learning Libraries for Petroleum Professionals

(TULSA, OK) Feb. 2nd, 2015 – PetroSkills has introduced ePetroTM, a new series of online learning programs for petroleum professionals. Designed to provide the industry knowledge required by professionals in the oil and gas industry, the new libraries are developed to the same exacting standards and in complement to the ePILOTTM online series for technical operation−over 800 hours of technical skills and safety training used at over 500 sites worldwide.

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21 Jan, 2015

Variation of Crude Oil Properties with Temperature in a Gathering Line

In the October and November 2014 Tips of the Month (TOTM), we demonstrated that Gas-Oil-Ratio (GOR) has a large impact on the capacity of crude oil gathering lines. If GOR is less than the saturation solution gas, the increase in GOR reduces the viscosity and density of crude oil which causes the pressure drop to decrease. However, if the GOR exceeds the saturation solution gas the system becomes two phase and pressure drop increases. The solution gas is a function of temperature, pressure, gas and liquid compositions. In this TOTM, we will study the impact of temperature on the crude oil properties in the gathering systems for the case presented in the November 2014 TOTM. Specifically, the variation of the crude oil relative density and viscosity with the temperature will be studied. Finally, the impact of temperature on the oil and gas velocity and pressure drop along a gathering line for nominal pressure of 6900 kPag (1000 psig) and nominal pipe size of 101.6 mm (4 inches) will be demonstrated using a multiphase rigorous method from a commercial simulator. The calculated properties, oil and gas velocities and pressure drops are presented in graphical format as a function of the oil stock tank volume flow rate, solution gas, Rs, and temperature.

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4 Nov, 2014

Impact of Solution Gas on Crude Oil Properties in a Gathering Line

In the October 2014 Tip of the Month (TOTM), we demonstrated that Gas-Oil-Ratio (GOR) has a large impact on the capacity of crude oil gathering lines. In general as GOR increased the pressure drop increased which lowered the line capacity. In addition, at high pressures and low GOR, pressure drop was lower than the pressure drop for dead oil (solution gas is zero) because the viscosity of live oil is lower than viscosity of dead oil. This effect was bigger for the smaller line diameter. In this TOTM, we will study the impact of solution gas (Rs) on the crude oil properties in the gathering systems for one of the cases presented in the October 2014 TOTM. Specifically, the variation of the crude oil relative density and viscosity with the solution gas (Rs) will be studied. Finally, the impact of solution gas (Rs) on the oil and gas velocity and pressure drop along a gathering line for nominal pressure of 6900 kPag (1000 psig) and nominal pipe size of 101.6 mm (4 inches) will be demonstrated using multiphase rigorous method from a commercial simulator. The calculated properties, oil and gas velocities and pressure drops are presented in graphical format as a function of the oil stock tank volume flow rate and solution gas, Rs

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7 Oct, 2014

Impact of Gas-Oil Ratio (GOR) on Crude Oil Pressure Drop in Gathering Systems

In the June 2008 Tip of the Month (TOTM), we demonstrated how general-purpose process simulation programs can be used to simulate gas dominated two-phase pipelines. In the August 2008 TOTM, we discussed the value of the simple Flanigan correlation and how it can be used to model and analyze the behavior of a wet gas transmission pipeline. The results of the Flanigan correlation were compared with more rigorous calculation methods for multiphase pipelines. In this TOTM, we will study the impact of gas-oil ratio (GOR) on pressure drop in crude oil gathering systems. Specifically, pressure drop along a gathering line for nominal pressures of 690, 3450, and 6900 kPag (100, 500, and 1000 psig) and nominal pipe size of 101.6 and 152.4 mm (4 and 6 inches) was calculated using multiphase rigorous method from commercial simulator. The calculated pressure drops are presented in graphical format as a function of the oil stock tank volume flow rate and GOR. Variation of thermophysical properties was considered.

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3 Sep, 2014

Lean Sweet Natural Gas Water Content Correlation

In the October, November, December 2007 and February 2014 Tips of the Month (TOTM), we studied in detail the water phase behaviors of sweet and sour natural gases and acid gas systems. We also evaluated the accuracy of different methods for estimating the water content of sour natural gas and acid gas systems. The water vapor content of natural gases in equilibrium with water is commonly estimated from Figure 6.1 of Campbell book or Figure 20.4 of Gas Processors and Suppliers Association (GPSA), including corrections for the molecular weight (relative density) of gas and salinity of water. In this article, we will present two new correlations for estimating the water content of lean and sweet natural gases. The performance of the proposed correlations is compared with the rigorous simulation and shortcut method software and other correlations.

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